-
-=head1 NAME
+S=head1 NAME
Catalyst::Manual::Cookbook - Cooking with Catalyst
=head1 RECIPES
-=head2 Force debug screen
+=head1 Basics
-You can force Catalyst to display the debug screen at the end of the request by
-placing a C<die()> call in the C<end> action.
+These recipes cover some basic stuff that is worth knowing for catalyst developers.
- sub end : Private {
- my ( $self, $c ) = @_;
- die "forced debug";
- }
+=head2 Delivering a Custom Error Page
-If you're tired of removing and adding this all the time, you can add a
-condition in the C<end> action. For example:
+By default, Catalyst will display its own error page whenever it
+encounters an error in your application. When running under C<-Debug>
+mode, the error page is a useful screen including the error message and
+L<Data::Dump> output of the relevant parts of the C<$c> context object.
+When not in C<-Debug>, users see a simple "Please come back later" screen.
- sub end : Private {
- my ( $self, $c ) = @_;
- die "forced debug" if $c->req->params->{dump_info};
- }
+To use a custom error page, use a special C<end> method to short-circuit
+the error processing. The following is an example; you might want to
+adjust it further depending on the needs of your application (for
+example, any calls to C<fillform> will probably need to go into this
+C<end> method; see L<Catalyst::Plugin::FillInForm>).
-Then just add to your query string C<"&dump_info=1">, or the like, to
-force debug output.
+ sub end : Private {
+ my ( $self, $c ) = @_;
+ if ( scalar @{ $c->error } ) {
+ $c->stash->{errors} = $c->error;
+ $c->stash->{template} = 'errors.tt';
+ $c->forward('MyApp::View::TT');
+ $c->error(0);
+ }
-=head2 Disable statistics
+ return 1 if $c->response->status =~ /^3\d\d$/;
+ return 1 if $c->response->body;
-Just add this line to your application class if you don't want those nifty
-statistics in your debug messages.
+ unless ( $c->response->content_type ) {
+ $c->response->content_type('text/html; charset=utf-8');
+ }
- sub Catalyst::Log::info { }
+ $c->forward('MyApp::View::TT');
+ }
-=head2 Scaffolding
+You can manually set errors in your code to trigger this page by calling
-Scaffolding is very simple with Catalyst.
+ $c->error( 'You broke me!' );
-The recommended way is to use Catalyst::Helper::Controller::Scaffold.
+=head2 Disable statistics
-Just install this module, and to scaffold a Class::DBI Model class, do the following:
+Just add this line to your application class if you don't want those nifty
+statistics in your debug messages.
-./script/myapp_create.pl controller <name> Scaffold <CDBI::Class>Scaffolding
+ sub Catalyst::Log::info { }
+=head2 Enable debug status in the environment
+Normally you enable the debugging info by adding the C<-Debug> flag to
+your C<use Catalyst> statement. However, you can also enable it using
+environment variable, so you can (for example) get debug info without
+modifying your application scripts. Just set C<CATALYST_DEBUG> or
+C<E<lt>MYAPPE<gt>_DEBUG> to a true value.
+=head2 Sessions
-=head2 File uploads
+When you have your users identified, you will want to somehow remember that
+fact, to save them from having to identify themselves for every single
+page. One way to do this is to send the username and password parameters in
+every single page, but that's ugly, and won't work for static pages.
-=head3 Single file upload with Catalyst
+Sessions are a method of saving data related to some transaction, and giving
+the whole collection a single ID. This ID is then given to the user to return
+to us on every page they visit while logged in. The usual way to do this is
+using a browser cookie.
-To implement uploads in Catalyst, you need to have a HTML form similar to
-this:
+Catalyst uses two types of plugins to represent sessions:
- <form action="/upload" method="post" enctype="multipart/form-data">
- <input type="hidden" name="form_submit" value="yes">
- <input type="file" name="my_file">
- <input type="submit" value="Send">
- </form>
+=head3 State
-It's very important not to forget C<enctype="multipart/form-data"> in
-the form.
+A State module is used to keep track of the state of the session between the
+users browser, and your application.
-Catalyst Controller module 'upload' action:
+A common example is the Cookie state module, which sends the browser a cookie
+containing the session ID. It will use default value for the cookie name and
+domain, so will "just work" when used.
- sub upload : Global {
- my ($self, $c) = @_;
+=head3 Store
- if ( $c->request->parameters->{form_submit} eq 'yes' ) {
+A Store module is used to hold all the data relating to your session, for
+example the users ID, or the items for their shopping cart. You can store data
+in memory (FastMmap), in a file (File) or in a database (DBI).
- if ( my $upload = $c->request->upload('my_file') ) {
+=head3 Authentication magic
- my $filename = $upload->filename;
- my $target = "/tmp/upload/$filename";
+If you have included the session modules in your application, the
+Authentication modules will automagically use your session to save and
+retrieve the user data for you.
- unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
- die( "Failed to copy '$filename' to '$target': $!" );
- }
- }
- }
+=head3 Using a session
- $c->stash->{template} = 'file_upload.html';
- }
+Once the session modules are loaded, the session is available as C<<
+$c->session >>, and can be writen to and read from as a simple hash reference.
-=head3 Multiple file upload with Catalyst
+=head3 EXAMPLE
-Code for uploading multiple files from one form needs a few changes:
+ use Catalyst qw/
+ Session
+ Session::Store::FastMmap
+ Session::State::Cookie
+ /;
-The form should have this basic structure:
- <form action="/upload" method="post" enctype="multipart/form-data">
- <input type="hidden" name="form_submit" value="yes">
- <input type="file" name="file1" size="50"><br>
- <input type="file" name="file2" size="50"><br>
- <input type="file" name="file3" size="50"><br>
- <input type="submit" value="Send">
- </form>
+ ## Write data into the session
-And in the controller:
+ sub add_item : Local {
+ my ( $self, $c ) = @_;
- sub upload : Local {
- my ($self, $c) = @_;
+ my $item_id = $c->req->param("item");
- if ( $c->request->parameters->{form_submit} eq 'yes' ) {
+ push @{ $c->session->{items} }, $item_id;
- for my $field ( $c->req->upload ) {
+ }
- my $upload = $c->req->upload($field);
- my $filename = $upload->filename;
- my $target = "/tmp/upload/$filename";
+ ## A page later we retrieve the data from the session:
- unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
- die( "Failed to copy '$filename' to '$target': $!" );
- }
- }
- }
+ sub get_items : Local {
+ my ( $self, $c ) = @_;
- $c->stash->{template} = 'file_upload.html';
- }
+ $c->stash->{items_to_display} = $c->session->{items};
-C<for my $field ($c-E<gt>req->upload)> loops automatically over all file
-input fields and gets input names. After that is basic file saving code,
-just like in single file upload.
+ }
-Notice: C<die>ing might not be what you want to do, when an error
-occurs, but it works as an example. A better idea would be to store
-error C<$!> in $c->stash->{error} and show a custom error template
-displaying this message.
-For more information about uploads and usable methods look at
-L<Catalyst::Request::Upload> and L<Catalyst::Request>.
+=head3 More information
-=head2 Authentication with Catalyst::Plugin::Authentication
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session>
-In this example, we'll use the
-L<Catalyst::Plugin::Authentication::Store::DBIC> store and the
-L<Catalyst::Plugin::Authentication::Credential::Password> credentials.
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-Cookie>
-In the lib/MyApp.pm package, we'll need to change the C<use Catalyst;>
-line to include the following modules:
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-URI>
- use Catalyst qw/
- ConfigLoader
- Authentication
- Authentication::Store::DBIC
- Authentication::Credential::Password
- Session
- Session::Store::FastMmap
- Session::State::Cookie
- HTML::Widget
- Static::Simple
- /;
-
-The Session, Session::Store::* and Session::State::* modules listed above
-ensure that we stay logged-in across multiple page-views.
-
-In our MyApp.yml configuration file, we'll need to add:
-
- authentication:
- dbic:
- user_class: MyApp::Model::DBIC::User
- user_field: username
- password_field: password
- password_type: hashed
- password_hash_type: SHA-1
-
-'user_class' is a DBIx::Class package for your users table.
-'user_field' tells which field (column) is used for username lookup.
-'password_field' is the password field in your table.
-The above settings for 'password_type' and 'password_hash_type' ensure that
-the password won't be stored in the database in clear text.
-
-In SQLite, the users table might be something like:
-
- CREATE TABLE user (
- id INTEGER PRIMARY KEY,
- username VARCHAR(100),
- password VARCHAR(100)
- );
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-FastMmap>
-Now we need to create a DBIC::SchemaLoader component for this database
-(changing "myapp.db" to wherever your SQLite database is).
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-File>
- script/myapp_create.pl model DBIC DBIC::SchemaLoader 'dbi:SQLite:myapp.db'
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-DBI>
-Now we can start creating our page controllers and templates.
-For our homepage, we create the file "root/index.tt" containing:
+=head2 Configure your application
- <html>
- <body>
- [% IF c.user %]
- <p>hello [% c.user.username %]</p>
- <p><a href="[% c.uri_for( '/logout' ) %]">logout</a></p>
- [% ELSE %]
- <p><a href="[% c.uri_for( '/login' ) %]">login</a></p>
- [% END %]
- </body>
- </html>
+You configure your application with the C<config> method in your
+application class. This can be hard-coded, or brought in from a
+separate configuration file.
-If the user is logged in, they will be shown their name, and a logout link.
-Otherwise, they will be shown a login link.
+=head3 Using YAML
-To display the homepage, we can uncomment the C<default> and C<end>
-subroutines in lib/MyApp/Controller/Root.pm and populate them as so:
+YAML is a method for creating flexible and readable configuration
+files. It's a great way to keep your Catalyst application configuration
+in one easy-to-understand location.
- sub default : Private {
- my ( $self, $c ) = @_;
-
- $c->stash->{template} = 'index.tt';
- }
+In your application class (e.g. C<lib/MyApp.pm>):
- sub end : Private {
- my ( $self, $c ) = @_;
-
- $c->forward( $c->view('TT') )
- unless $c->response->body || $c->response->redirect;
- }
+ use YAML;
+ # application setup
+ __PACKAGE__->config( YAML::LoadFile(__PACKAGE__->config->{'home'} . '/myapp.yml') );
+ __PACKAGE__->setup;
+
+Now create C<myapp.yml> in your application home:
-The login template is very simple, as L<HTML::Widget> will handle the
-HTML form creation for use. This is saved as "root/login.tt".
+ --- #YAML:1.0
+ # DO NOT USE TABS FOR INDENTATION OR label/value SEPARATION!!!
+ name: MyApp
- <html>
- <head>
- <link href="[% c.uri_for('/static/simple.css') %]" rel="stylesheet" type="text/css">
- </head>
- <body>
- [% result %]
- </body>
- </html>
+ # session; perldoc Catalyst::Plugin::Session::FastMmap
+ session:
+ expires: '3600'
+ rewrite: '0'
+ storage: '/tmp/myapp.session'
-For the HTML form to look correct, we also copy the C<simple.css> file
-from the L<HTML::Widget> distribution into our "root/static" folder.
-This file is automatically server by the L<Catalyst::Plugin::Static::Simple>
-module which we loaded in our lib/MyApp.pm package.
+ # emails; perldoc Catalyst::Plugin::Email
+ # this passes options as an array :(
+ email:
+ - SMTP
+ - localhost
-To handle login requests, we first create a controller, like so:
+This is equivalent to:
- script/myapp_create.pl controller Login
+ # configure base package
+ __PACKAGE__->config( name => MyApp );
+ # configure authentication
+ __PACKAGE__->config->{authentication} = {
+ user_class => 'MyApp::Model::MyDB::Customer',
+ ...
+ };
+ # configure sessions
+ __PACKAGE__->config->{session} = {
+ expires => 3600,
+ ...
+ };
+ # configure email sending
+ __PACKAGE__->config->{email} = [qw/SMTP localhost/];
-In the lib/MyApp/Controller/Login.pm package, we can then uncomment the
-C<default> subroutine, and populate it, as below.
+See also L<YAML>.
-First the widget is created, it needs the 'action' set, and 'username' and
-'password' fields and a submit button added.
+=head1 Skipping your VCS's directories
-Then, if we've received a username and password in the request, we attempt
-to login. If successful, we redirect to the homepage; if not the login form
-will be displayed again.
+Catalyst uses Module::Pluggable to load Models, Views and Controllers.
+Module::Pluggable will scan through all directories and load modules
+it finds. Sometimes you might want to skip some of these directories,
+for example when your version control system makes a subdirectory with
+meta-information in every version-controlled directory. While
+Catalyst skips subversion and CVS directories already, there are other
+source control systems. Here is the configuration you need to add
+their directories to the list to skip.
- sub default : Private {
- my ( $self, $c ) = @_;
-
- $c->widget->method('POST')->action( $c->uri_for('/login') );
- $c->widget->element( 'Textfield', 'username' )->label( 'Username' );
- $c->widget->element( 'Password', 'password' )->label( 'Password' );
- $c->widget->element( 'Submit' )->value( 'Login' );
-
- my $result = $c->widget->process( $c->req );
-
- if ( my $user = $result->param('username')
- and my $pass = $result->param('password') )
- {
- if ( $c->login( $user, $pass ) ) {
- $c->response->redirect( $c->uri_for( "/" ) );
- return;
- }
- }
-
- $c->stash->{template} = 'login.tt';
- $c->stash->{result} = $result;
- }
+You can make catalyst skip these directories using the Catalyst config:
-To handle logout's, we create a new controller:
+ # Configure the application
+ __PACKAGE__->config(
+ name => 'MyApp',
+ setup_components => { except => qr/SCCS/ },
+ );
- script/myapp_create.pl controller Logout
+See the Module::Pluggable manual page for more information on B<except>
+and other options.
-Then in the lib/MyApp/Controller/Logout.pm package, we change the
-C<default> subroutine, to logout and then redirect back to the
-homepage.
+=head1 Users and Access Control
- sub default : Private {
- my ( $self, $c ) = @_;
-
- $c->logout;
-
- $c->response->redirect( $c->uri_for( "/" ) );
- }
+Most multiuser, and some single user web applications require that
+users identify themselves, and the application is often required to
+define those roles. The recipes below describe some ways of doing
+this.
-Remember that to test this, we would first need to add a user to the
-database, ensuring that the password field is saved as the SHA1 hash
-of our desired password.
+=head2 Authentication (logging in)
+This is extensively covered in other documentation; see in particular
+L<Catalyst::Plugin::Authentication> and the Authentication chapter
+of the Tutorial at L<Catalyst::Manual::Tutorial::Authorization>.
=head2 Pass-through login (and other actions)
}
}
-=head2 How to use Catalyst without mod_perl
-Catalyst applications give optimum performance when run under mod_perl.
-However sometimes mod_perl is not an option, and running under CGI is
-just too slow. There's also an alternative to mod_perl that gives
-reasonable performance named FastCGI.
+=head2 Role-based Authorization
-=head3 Using FastCGI
+For more advanced access control, you may want to consider using role-based
+authorization. This means you can assign different roles to each user, e.g.
+"user", "admin", etc.
-To quote from L<http://www.fastcgi.com/>: "FastCGI is a language
-independent, scalable, extension to CGI that provides high performance
-without the limitations of specific server APIs." Web server support
-is provided for Apache in the form of C<mod_fastcgi> and there is Perl
-support in the C<FCGI> module. To convert a CGI Catalyst application
-to FastCGI one needs to initialize an C<FCGI::Request> object and loop
-while the C<Accept> method returns zero. The following code shows how
-it is done - and it also works as a normal, single-shot CGI script.
+The C<login> and C<logout> methods and view template are exactly the same as
+in the previous example.
- #!/usr/bin/perl
- use strict;
- use FCGI;
- use MyApp;
+The L<Catalyst::Plugin::Authorization::Roles> plugin is required when
+implementing roles:
- my $request = FCGI::Request();
- while ($request->Accept() >= 0) {
- MyApp->run;
- }
+ use Catalyst qw/
+ Authentication
+ Authentication::Credential::Password
+ Authentication::Store::Htpasswd
+ Authorization::Roles
+ /;
-Any initialization code should be included outside the request-accept
-loop.
+Roles are implemented automatically when using
+L<Catalyst::Authentication::Store::Htpasswd>:
-There is one little complication, which is that C<MyApp-E<gt>run> outputs a
-complete HTTP response including the status line (e.g.:
-"C<HTTP/1.1 200>").
-FastCGI just wants a set of headers, so the sample code captures the
-output and drops the first line if it is an HTTP status line (note:
-this may change).
+ # no additional role configuration required
+ __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
-The Apache C<mod_fastcgi> module is provided by a number of Linux
-distro's and is straightforward to compile for most Unix-like systems.
-The module provides a FastCGI Process Manager, which manages FastCGI
-scripts. You configure your script as a FastCGI script with the
-following Apache configuration directives:
+Or can be set up manually when using L<Catalyst::Authentication::Store::DBIC>:
- <Location /fcgi-bin>
- AddHandler fastcgi-script fcgi
- </Location>
+ # Authorization using a many-to-many role relationship
+ __PACKAGE__->config->{authorization}{dbic} = {
+ 'role_class' => 'My::Model::DBIC::Role',
+ 'role_field' => 'name',
+ 'user_role_user_field' => 'user',
-or:
+ # DBIx::Class only (omit if using Class::DBI)
+ 'role_rel' => 'user_role',
- <Location /fcgi-bin>
- SetHandler fastcgi-script
- Action fastcgi-script /path/to/fcgi-bin/fcgi-script
- </Location>
+ # Class::DBI only, (omit if using DBIx::Class)
+ 'user_role_class' => 'My::Model::CDBI::UserRole'
+ 'user_role_role_field' => 'role',
+ };
-C<mod_fastcgi> provides a number of options for controlling the FastCGI
-scripts spawned; it also allows scripts to be run to handle the
-authentication, authorization, and access check phases.
+To restrict access to any action, you can use the C<check_user_roles> method:
-For more information see the FastCGI documentation, the C<FCGI> module
-and L<http://www.fastcgi.com/>.
+ sub restricted : Local {
+ my ( $self, $c ) = @_;
-=head2 Serving static content
-
-Serving static content in Catalyst can be somewhat tricky; this recipe
-shows one possible solution. Using this recipe will serve all static
-content through Catalyst when developing with the built-in HTTP::Daemon
-server, and will make it easy to use Apache to serve the content when
-your app goes into production.
-
-Static content is best served from a single directory within your root
-directory. Having many different directories such as C<root/css> and
-C<root/images> requires more code to manage, because you must separately
-identify each static directory--if you decide to add a C<root/js>
-directory, you'll need to change your code to account for it. In
-contrast, keeping all static directories as subdirectories of a main
-C<root/static> directory makes things much easier to manager. Here's an
-example of a typical root directory structure:
-
- root/
- root/content.tt
- root/controller/stuff.tt
- root/header.tt
- root/static/
- root/static/css/main.css
- root/static/images/logo.jpg
- root/static/js/code.js
+ $c->detach("unauthorized")
+ unless $c->check_user_roles( "admin" );
+ # do something restricted here
+ }
-All static content lives under C<root/static> with everything else being
-Template Toolkit files. Now you can identify the static content by
-matching C<static> from within Catalyst.
+You can also use the C<assert_user_roles> method. This just gives an error if
+the current user does not have one of the required roles:
-=head3 Serving with HTTP::Daemon (myapp_server.pl)
+ sub also_restricted : Global {
+ my ( $self, $c ) = @_;
+ $c->assert_user_roles( qw/ user admin / );
+ }
+
+=head2 Authentication/Authorization
-To serve these files under the standalone server, we first must load the
-Static plugin. Install L<Catalyst::Plugin::Static> if it's not already
-installed.
+This is done in several steps:
-In your main application class (MyApp.pm), load the plugin:
+=over 4
- use Catalyst qw/-Debug FormValidator Static OtherPlugin/;
+=item Verification
-You will also need to make sure your end method does I<not> forward
-static content to the view, perhaps like this:
+Getting the user to identify themselves, by giving you some piece of
+information known only to you and the user. Then you can assume that the user
+is who they say they are. This is called B<credential verification>.
- sub end : Private {
- my ( $self, $c ) = @_;
+=item Authorization
- $c->forward( 'MyApp::View::TT' )
- unless ( $c->res->body || !$c->stash->{template} );
- }
+Making sure the user only accesses functions you want them to access. This is
+done by checking the verified users data against your internal list of groups,
+or allowed persons for the current page.
-This code will only forward to the view if a template has been
-previously defined by a controller and if there is not already data in
-C<$c-E<gt>res-E<gt>body>.
+=back
-Next, create a controller to handle requests for the /static path. Use
-the Helper to save time. This command will create a stub controller as
-C<lib/MyApp/Controller/Static.pm>.
+=head3 Modules
- $ script/myapp_create.pl controller Static
+The Catalyst Authentication system is made up of many interacting modules, to
+give you the most flexibility possible.
-Edit the file and add the following methods:
+=head4 Credential verifiers
- # serve all files under /static as static files
- sub default : Path('/static') {
- my ( $self, $c ) = @_;
+A Credential module tables the user input, and passes it to a Store, or some
+other system, for verification. Typically, a user object is created by either
+this module or the Store and made accessible by a C<< $c->user >> call.
- # Optional, allow the browser to cache the content
- $c->res->headers->header( 'Cache-Control' => 'max-age=86400' );
+Examples:
- $c->serve_static; # from Catalyst::Plugin::Static
- }
+ Password - Simple username/password checking.
+ HTTPD - Checks using basic HTTP auth.
+ TypeKey - Check using the typekey system.
- # also handle requests for /favicon.ico
- sub favicon : Path('/favicon.ico') {
- my ( $self, $c ) = @_;
+=head3 Storage backends
- $c->serve_static;
- }
+A Storage backend contains the actual data representing the users. It is
+queried by the credential verifiers. Updating the store is not done within
+this system, you will need to do it yourself.
-You can also define a different icon for the browser to use instead of
-favicon.ico by using this in your HTML header:
+Examples:
- <link rel="icon" href="/static/myapp.ico" type="image/x-icon" />
+ DBIC - Storage using a database.
+ Minimal - Storage using a simple hash (for testing).
-=head3 Common problems
+=head3 User objects
-The Static plugin makes use of the C<shared-mime-info> package to
-automatically determine MIME types. This package is notoriously
-difficult to install, especially on win32 and OS X. For OS X the easiest
-path might be to install Fink, then use C<apt-get install
-shared-mime-info>. Restart the server, and everything should be fine.
+A User object is created by either the storage backend or the credential
+verifier, and filled with the retrieved user information.
-Make sure you are using the latest version (>= 0.16) for best
-results. If you are having errors serving CSS files, or if they get
-served as text/plain instead of text/css, you may have an outdated
-shared-mime-info version. You may also wish to simply use the following
-code in your Static controller:
+Examples:
- if ($c->req->path =~ /css$/i) {
- $c->serve_static( "text/css" );
- } else {
- $c->serve_static;
- }
+ Hash - A simple hash of keys and values.
-=head3 Serving with Apache
+=head3 ACL authorization
-When using Apache, you can completely bypass Catalyst and the Static
-controller by intercepting requests for the C<root/static> path at the
-server level. All that is required is to define a DocumentRoot and add a
-separate Location block for your static content. Here is a complete
-config for this application under mod_perl 1.x:
+ACL stands for Access Control List. The ACL plugin allows you to regulate
+access on a path by path basis, by listing which users, or roles, have access
+to which paths.
- <Perl>
- use lib qw(/var/www/MyApp/lib);
- </Perl>
- PerlModule MyApp
+=head3 Roles authorization
- <VirtualHost *>
- ServerName myapp.example.com
- DocumentRoot /var/www/MyApp/root
- <Location />
- SetHandler perl-script
- PerlHandler MyApp
- </Location>
- <LocationMatch "/(static|favicon.ico)">
- SetHandler default-handler
- </LocationMatch>
- </VirtualHost>
+Authorization by roles is for assigning users to groups, which can then be
+assigned to ACLs, or just checked when needed.
-And here's a simpler example that'll get you started:
+=head3 Logging in
- Alias /static/ "/my/static/files/"
- <Location "/static">
- SetHandler none
- </Location>
+When you have chosen your modules, all you need to do is call the C<<
+$c->login >> method. If called with no parameters, it will try to find
+suitable parameters, such as B<username> and B<password>, or you can pass it
+these values.
-=head2 Forwarding with arguments
+=head3 Checking roles
-Sometimes you want to pass along arguments when forwarding to another
-action. As of version 5.30, arguments can be passed in the call to
-C<forward>; in earlier versions, you can manually set the arguments in
-the Catalyst Request object:
+Role checking is done by using the C<< $c->check_user_roles >> method, this will
+check using the currently logged in user (via C<< $c->user >>). You pass it
+the name of a role to check, and it returns true if the user is a member.
- # version 5.30 and later:
- $c->forward('/wherever', [qw/arg1 arg2 arg3/]);
+=head3 EXAMPLE
- # pre-5.30
- $c->req->args([qw/arg1 arg2 arg3/]);
- $c->forward('/wherever');
+ use Catalyst qw/Authentication
+ Authentication::Credential::Password
+ Authentication::Store::Htpasswd
+ Authorization::Roles/;
-(See the L<Catalyst::Manual::Intro> Flow_Control section for more
-information on passing arguments via C<forward>.)
+ __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
-=head2 Configure your application
+ sub login : Local {
+ my ($self, $c) = @_;
-You configure your application with the C<config> method in your
-application class. This can be hard-coded, or brought in from a
-separate configuration file.
+ if ( my $user = $c->req->param("user")
+ and my $password = $c->req->param("password") )
+ {
+ if ( $c->login( $user, $password ) ) {
+ $c->res->body( "hello " . $c->user->name );
+ } else {
+ # login incorrect
+ }
+ }
+ else {
+ # invalid form input
+ }
+ }
-=head3 Using YAML
+ sub restricted : Local {
+ my ( $self, $c ) = @_;
-YAML is a method for creating flexible and readable configuration
-files. It's a great way to keep your Catalyst application configuration
-in one easy-to-understand location.
+ $c->detach("unauthorized")
+ unless $c->check_user_roles( "admin" );
-In your application class (e.g. C<lib/MyApp.pm>):
+ # do something restricted here
+ }
- use YAML;
- # application setup
- __PACKAGE__->config( YAML::LoadFile(__PACKAGE__->config->{'home'} . '/myapp.yml') );
- __PACKAGE__->setup;
+=head3 Using authentication in a testing environment
-Now create C<myapp.yml> in your application home:
+Ideally, to write tests for authentication/authorization code one would first
+set up a test database with known data, then use
+L<Test::WWW::Mechanize::Catalyst> to simulate a user logging in. Unfortunately
+the former can be rather awkward, which is why it's a good thing that the
+authentication framework is so flexible.
- --- #YAML:1.0
- # DO NOT USE TABS FOR INDENTATION OR label/value SEPARATION!!!
- name: MyApp
+Instead of using a test database, one can simply change the authentication
+store to something a bit easier to deal with in a testing
+environment. Additionally, this has the advantage of not modifying one's
+database, which can be problematic if one forgets to use the testing instead of
+production database.
- # session; perldoc Catalyst::Plugin::Session::FastMmap
- session:
- expires: '3600'
- rewrite: '0'
- storage: '/tmp/myapp.session'
+e.g.,
- # emails; perldoc Catalyst::Plugin::Email
- # this passes options as an array :(
- email:
- - SMTP
- - localhost
+ use Catalyst::Plugin::Authentication::Store::Minimal::Backend;
-This is equivalent to:
+ # Sets up the user `test_user' with password `test_pass'
+ MyApp->default_auth_store(
+ Catalyst::Plugin::Authentication::Store::Minimal::Backend->new({
+ test_user => { password => 'test_pass' },
+ })
+ );
- # configure base package
- __PACKAGE__->config( name => MyApp );
- # configure authentication
- __PACKAGE__->config->{authentication} = {
- user_class => 'MyApp::Model::MyDB::Customer',
- ...
- };
- # configure sessions
- __PACKAGE__->config->{session} = {
- expires => 3600,
- ...
- };
- # configure email sending
- __PACKAGE__->config->{email} = [qw/SMTP localhost/];
+Now, your test code can call C<$c->login('test_user', 'test_pass')> and
+successfully login, without messing with the database at all.
-See also L<YAML>.
+=head3 More information
-=head2 Using existing DBIC (etc.) classes with Catalyst
+L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authentication> has a longer explanation.
-Many people have existing Model classes that they would like to use with
-Catalyst (or, conversely, they want to write Catalyst models that can be
-used outside of Catalyst, e.g. in a cron job). It's trivial to write a
-simple component in Catalyst that slurps in an outside Model:
+=head2 Authorization
- package MyApp::Model::DB;
- use base qw/Catalyst::Model::DBIC::Schema/;
- __PACKAGE__->config(
- schema_class => 'Some::DBIC::Schema',
- connect_info => ['dbi:SQLite:foo.db', '', '', {AutoCommit=>1}];
- );
- 1;
+=head3 Introduction
-and that's it! Now C<Some::DBIC::Schema> is part of your
-Cat app as C<MyApp::Model::DB>.
+Authorization is the step that comes after authentication. Authentication
+establishes that the user agent is really representing the user we think it's
+representing, and then authorization determines what this user is allowed to
+do.
-=head2 Delivering a Custom Error Page
+=head3 Role Based Access Control
-By default, Catalyst will display its own error page whenever it
-encounters an error in your application. When running under C<-Debug>
-mode, the error page is a useful screen including the error message and
-L<Data::Dump> output of the relevant parts of the C<$c> context object.
-When not in C<-Debug>, users see a simple "Please come back later" screen.
+Under role based access control each user is allowed to perform any number of
+roles. For example, at a zoo no one but specially trained personnel can enter
+the moose cage (Mynd you, møøse bites kan be pretty nasti!). For example:
-To use a custom error page, use a special C<end> method to short-circuit
-the error processing. The following is an example; you might want to
-adjust it further depending on the needs of your application (for
-example, any calls to C<fillform> will probably need to go into this
-C<end> method; see L<Catalyst::Plugin::FillInForm>).
+ package Zoo::Controller::MooseCage;
- sub end : Private {
+ sub feed_moose : Local {
my ( $self, $c ) = @_;
- if ( scalar @{ $c->error } ) {
- $c->stash->{errors} = $c->error;
- $c->stash->{template} = 'errors.tt';
- $c->forward('MyApp::View::TT');
- $c->error(0);
- }
-
- return 1 if $c->response->status =~ /^3\d\d$/;
- return 1 if $c->response->body;
-
- unless ( $c->response->content_type ) {
- $c->response->content_type('text/html; charset=utf-8');
- }
-
- $c->forward('MyApp::View::TT');
- }
-
-You can manually set errors in your code to trigger this page by calling
-
- $c->error( 'You broke me!' );
-
-=head2 Require user logins
-
-It's often useful to restrict access to your application to a set of
-registered users, forcing everyone else to the login page until they're
-signed in.
-
-To implement this in your application make sure you have a customer
-table with username and password fields and a corresponding Model class
-in your Catalyst application, then make the following changes:
-
-=head3 lib/MyApp.pm
-
- use Catalyst qw/
- Authentication
- Authentication::Store::DBIC
- Authentication::Credential::Password
- /;
-
- __PACKAGE__->config->{authentication}->{dbic} = {
- 'user_class' => 'My::Model::DBIC::User',
- 'user_field' => 'username',
- 'password_field' => 'password'
- 'password_type' => 'hashed',
- 'password_hash_type'=> 'SHA-1'
- };
-
- sub auto : Private {
- my ($self, $c) = @_;
- my $login_path = 'user/login';
-
- # allow people to actually reach the login page!
- if ($c->request->path eq $login_path) {
- return 1;
- }
-
- # if a user doesn't exist, force login
- if ( !$c->user_exists ) {
- # force the login screen to be shown
- $c->response->redirect($c->request->base . $login_path);
+ $c->model( "Moose" )->eat( $c->req->param("food") );
}
- # otherwise, we have a user - continue with the processing chain
- return 1;
- }
-
-=head3 lib/MyApp/Controller/User.pm
+With this action, anyone can just come into the moose cage and feed the moose,
+which is a very dangerous thing. We need to restrict this action, so that only
+a qualified moose feeder can perform that action.
- sub login : Path('/user/login') {
- my ($self, $c) = @_;
+The Authorization::Roles plugin let's us perform role based access control
+checks. Let's load it:
- # default template
- $c->stash->{'template'} = "user/login.tt";
- # default form message
- $c->stash->{'message'} = 'Please enter your username and password';
+ use Catalyst qw/
+ Authentication # yadda yadda
+ Authorization::Roles
+ /;
- if ( $c->request->param('username') ) {
- # try to log the user in
- # login() is provided by ::Authentication::Credential::Password
- if( $c->login(
- $c->request->param('username'),
- $c->request->param('password'),
- ) {
+And now our action should look like this:
- # if login() returns 1, user is now logged in
- $c->response->redirect('/some/page');
- }
+ sub feed_moose : Local {
+ my ( $self, $c ) = @_;
- # otherwise we failed to login, try again!
- $c->stash->{'message'} =
- 'Unable to authenticate the login details supplied';
+ if ( $c->check_roles( "moose_feeder" ) ) {
+ $c->model( "Moose" )->eat( $c->req->param("food") );
+ } else {
+ $c->stash->{error} = "unauthorized";
+ }
}
- }
-
- sub logout : Path('/user/logout') {
- my ($self, $c) = @_;
- # log the user out
- $c->logout;
-
- # do the 'default' action
- $c->response->redirect($c->request->base);
- }
-
-
-=head3 root/base/user/login.tt
-
- [% INCLUDE header.tt %]
- <form action="/user/login" method="POST" name="login_form">
- [% message %]<br />
- <label for="username">username:</label><br />
- <input type="text" id="username" name="username" /><br />
-
- <label for="password">password:</label><br />
- <input type="password" id="password" name="password" /><br />
-
- <input type="submit" value="log in" name="form_submit" />
- </form>
- [% INCLUDE footer.tt %]
-
-=head2 Role-based Authorization
-
-For more advanced access control, you may want to consider using role-based
-authorization. This means you can assign different roles to each user, e.g.
-"user", "admin", etc.
-
-The C<login> and C<logout> methods and view template are exactly the same as
-in the previous example.
-
-The L<Catalyst::Plugin::Authorization::Roles> plugin is required when
-implementing roles:
-
- use Catalyst qw/
- Authentication
- Authentication::Credential::Password
- Authentication::Store::Htpasswd
- Authorization::Roles
- /;
-
-Roles are implemented automatically when using
-L<Catalyst::Authentication::Store::Htpasswd>:
- # no additional role configuration required
- __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
-
-Or can be set up manually when using L<Catalyst::Authentication::Store::DBIC>:
-
- # Authorization using a many-to-many role relationship
- __PACKAGE__->config->{authorization}{dbic} = {
- 'role_class' => 'My::Model::DBIC::Role',
- 'role_field' => 'name',
- 'user_role_user_field' => 'user',
-
- # DBIx::Class only (omit if using Class::DBI)
- 'role_rel' => 'user_role',
-
- # Class::DBI only, (omit if using DBIx::Class)
- 'user_role_class' => 'My::Model::CDBI::UserRole'
- 'user_role_role_field' => 'role',
- };
-
-To restrict access to any action, you can use the C<check_user_roles> method:
-
- sub restricted : Local {
- my ( $self, $c ) = @_;
-
- $c->detach("unauthorized")
- unless $c->check_user_roles( "admin" );
-
- # do something restricted here
- }
-
-You can also use the C<assert_user_roles> method. This just gives an error if
-the current user does not have one of the required roles:
-
- sub also_restricted : Global {
- my ( $self, $c ) = @_;
- $c->assert_user_roles( qw/ user admin / );
- }
-
-=head2 Building PAR Packages
-
-You know the problem, you got a application perfectly running on your
-development box, but then *shudder* you have to quickly move it to
-another one for demonstration/deployment/testing...
-
-PAR packages can save you from a lot of trouble here.
-They are usual Zip files that contain a blib tree, you can even
-include all prereqs and a perl interpreter by setting a few flags!
-
-=head3 Follow these few points to try it out!
-
-1. Install Catalyst 5.61 (or later) and PAR 0.89
-
- % perl -MCPAN -e 'install Catalyst'
- ...
- % perl -MCPAN -e 'install PAR'
- ...
-
-2. Create a application
-
- % catalyst.pl MyApp
- ...
- % cd MyApp
+This checks C<< $c->user >>, and only if the user has B<all> the roles in the
+list, a true value is returned.
-3. Add these lines to Makefile.PL (below "catalyst_files();")
+C<check_roles> has a sister method, C<assert_roles>, which throws an exception
+if any roles are missing.
- catalyst_par_core(); # Include modules that are also included
- # in the standard Perl distribution,
- # this is optional but highly suggested
+Some roles that might actually make sense in, say, a forum application:
- catalyst_par(); # Generate a PAR as soon as the blib
- # directory is ready
+=over 4
-4. Prepare the Makefile, test your app, create a PAR (the two Makefile.PL calls are no typo)
+=item *
- % perl Makefile.PL
- ...
- % make test
- ...
- % perl Makefile.PL
- ...
+administrator
-Future versions of Catalyst (5.62 and newer) will use a similar but more elegant calling convention.
+=item *
- % perl Makefile.PL
- ...
- % make catalyst_par
- ...
+moderator
-Congratulations! Your package "myapp.par" is ready, the following
-steps are just optional.
+=back
-5. Test your PAR package with "parl" (no typo) :)
+each with a distinct task (system administration versus content administration).
- % parl myapp.par
- Usage:
- [parl] myapp[.par] [script] [arguments]
+=head3 Access Control Lists
- Examples:
- parl myapp.par myapp_server.pl -r
- myapp myapp_cgi.pl
+Checking for roles all the time can be tedious and error prone.
- Available scripts:
- myapp_cgi.pl
- myapp_create.pl
- myapp_fastcgi.pl
- myapp_server.pl
- myapp_test.pl
+The Authorization::ACL plugin let's us declare where we'd like checks to be
+done automatically for us.
- % parl myapp.par myapp_server.pl
- You can connect to your server at http://localhost:3000
+For example, we may want to completely block out anyone who isn't a
+C<moose_feeder> from the entire C<MooseCage> controller:
-Yes, this nifty little starter application gets automatically included.
-You can also use "catalyst_par_script('myapp_server.pl')" to set a
-default script to execute.
+ Zoo->deny_access_unless( "/moose_cage", [qw/moose_feeder/] );
-6. Want to create a binary that includes the Perl interpreter? No
-problem!
+The role list behaves in the same way as C<check_roles>. However, the ACL
+plugin isn't limited to just interacting with the Roles plugin. We can use a
+code reference instead. For example, to allow either moose trainers or moose
+feeders into the moose cage, we can create a more complex check:
- % pp -o myapp myapp.par
- % ./myapp myapp_server.pl
- You can connect to your server at http://localhost:3000
+ Zoo->deny_access_unless( "/moose_cage", sub {
+ my $c = shift;
+ $c->check_roles( "moose_trainer" ) || $c->check_roles( "moose_feeder" );
+ });
-=head2 mod_perl Deployment
+The more specific a role, the earlier it will be checked. Let's say moose
+feeders are now restricted to only the C<feed_moose> action, while moose
+trainers get access everywhere:
-In today's entry, I'll be talking about deploying an application in
-production using Apache and mod_perl.
+ Zoo->deny_access_unless( "/moose_cage", [qw/moose_trainer/] );
+ Zoo->allow_access_if( "/moose_cage/feed_moose", [qw/moose_feeder/]);
-=head3 Pros & Cons
+When the C<feed_moose> action is accessed the second check will be made. If the
+user is a C<moose_feeder>, then access will be immediately granted. Otherwise,
+the next rule in line will be tested - the one checking for a C<moose_trainer>.
+If this rule is not satisfied, access will be immediately denied.
-mod_perl is the best solution for many applications, but I'll list some pros
-and cons so you can decide for yourself. The other production deployment
-option is FastCGI, which I'll talk about in a future calendar article.
+Rules applied to the same path will be checked in the order they were added.
-=head4 Pros
+Lastly, handling access denial events is done by creating an C<access_denied>
+private action:
-=head4 Speed
+ sub access_denied : Private {
+ my ( $self, $c, $action ) = @_;
-mod_perl is very fast and your app will benefit from being loaded in memory
-within each Apache process.
+
+ }
-=head4 Shared memory for multiple apps
+This action works much like auto, in that it is inherited across namespaces
+(not like object oriented code). This means that the C<access_denied> action
+which is B<nearest> to the action which was blocked will be triggered.
-If you need to run several Catalyst apps on the same server, mod_perl will
-share the memory for common modules.
+If this action does not exist, an error will be thrown, which you can clean up
+in your C<end> private action instead.
-=head4 Cons
+Also, it's important to note that if you restrict access to "/" then C<end>,
+C<default>, etc will also be restricted.
-=head4 Memory usage
+ MyApp->acl_allow_root_internals;
-Since your application is fully loaded in memory, every Apache process will
-be rather large. This means a large Apache process will be tied up while
-serving static files, large files, or dealing with slow clients. For this
-reason, it is best to run a two-tiered web architecture with a lightweight
-frontend server passing dynamic requests to a large backend mod_perl
-server.
+will create rules that permit access to C<end>, C<begin>, and C<auto> in the
+root of your app (but not in any other controller).
-=head4 Reloading
+=head1 Models
-Any changes made to the core code of your app require a full Apache restart.
-Catalyst does not support Apache::Reload or StatINC. This is another good
-reason to run a frontend web server where you can set up an
-C<ErrorDocument 502> page to report that your app is down for maintenance.
+Models are where application data belongs. Catalyst is exteremely
+flexible with the kind of models that it can use. The recipes here
+are just the start.
-=head4 Cannot run multiple versions of the same app
+=head2 Using existing DBIC (etc.) classes with Catalyst
-It is not possible to run two different versions of the same application in
-the same Apache instance because the namespaces will collide.
+Many people have existing Model classes that they would like to use with
+Catalyst (or, conversely, they want to write Catalyst models that can be
+used outside of Catalyst, e.g. in a cron job). It's trivial to write a
+simple component in Catalyst that slurps in an outside Model:
-=head4 Setup
+ package MyApp::Model::DB;
+ use base qw/Catalyst::Model::DBIC::Schema/;
+ __PACKAGE__->config(
+ schema_class => 'Some::DBIC::Schema',
+ connect_info => ['dbi:SQLite:foo.db', '', '', {AutoCommit=>1}];
+ );
+ 1;
-Now that we have that out of the way, let's talk about setting up mod_perl
-to run a Catalyst app.
+and that's it! Now C<Some::DBIC::Schema> is part of your
+Cat app as C<MyApp::Model::DB>.
-=head4 1. Install Catalyst::Engine::Apache
+=head2 DBIx::Class as a Catalyst Model
-You should install the latest versions of both Catalyst and
-Catalyst::Engine::Apache. The Apache engines were separated from the
-Catalyst core in version 5.50 to allow for updates to the engine without
-requiring a new Catalyst release.
+See L<Catalyst::Model::DBIC::Schema>.
-=head4 2. Install Apache with mod_perl
+=head2 XMLRPC
-Both Apache 1.3 and Apache 2 are supported, although Apache 2 is highly
-recommended. With Apache 2, make sure you are using the prefork MPM and not
-the worker MPM. The reason for this is that many Perl modules are not
-thread-safe and may have problems running within the threaded worker
-environment. Catalyst is thread-safe however, so if you know what you're
-doing, you may be able to run using worker.
+Unlike SOAP, XMLRPC is a very simple (and imo elegant) web-services
+protocol, exchanging small XML messages like these:
-In Debian, the following commands should get you going.
+Request:
- apt-get install apache2-mpm-prefork
- apt-get install libapache2-mod-perl2
+ POST /api HTTP/1.1
+ TE: deflate,gzip;q=0.3
+ Connection: TE, close
+ Accept: text/xml
+ Accept: multipart/*
+ Host: 127.0.0.1:3000
+ User-Agent: SOAP::Lite/Perl/0.60
+ Content-Length: 192
+ Content-Type: text/xml
-=head4 3. Configure your application
+ <?xml version="1.0" encoding="UTF-8"?>
+ <methodCall>
+ <methodName>add</methodName>
+ <params>
+ <param><value><int>1</int></value></param>
+ <param><value><int>2</int></value></param>
+ </params>
+ </methodCall>
-Every Catalyst application will automagically become a mod_perl handler
-when run within mod_perl. This makes the configuration extremely easy.
-Here is a basic Apache 2 configuration.
+Response:
- PerlSwitches -I/var/www/MyApp/lib
- PerlModule MyApp
-
- <Location />
- SetHandler modperl
- PerlResponseHandler MyApp
- </Location>
+ Connection: close
+ Date: Tue, 20 Dec 2005 07:45:55 GMT
+ Content-Length: 133
+ Content-Type: text/xml
+ Status: 200
+ X-Catalyst: 5.70
-The most important line here is C<PerlModule MyApp>. This causes mod_perl
-to preload your entire application into shared memory, including all of your
-controller, model, and view classes and configuration. If you have -Debug
-mode enabled, you will see the startup output scroll by when you first
-start Apache.
+ <?xml version="1.0" encoding="us-ascii"?>
+ <methodResponse>
+ <params>
+ <param><value><int>3</int></value></param>
+ </params>
+ </methodResponse>
-For an example Apache 1.3 configuration, please see the documentation for
-L<Catalyst::Engine::Apache::MP13>.
+Now follow these few steps to implement the application:
-=head3 Test It
+1. Install Catalyst (5.61 or later), Catalyst::Plugin::XMLRPC (0.06 or
+later) and SOAP::Lite (for XMLRPCsh.pl).
-That's it, your app is now a full-fledged mod_perl application! Try it out
-by going to http://your.server.com/.
+2. Create an application framework:
-=head3 Other Options
+ % catalyst.pl MyApp
+ ...
+ % cd MyApp
-=head4 Non-root location
+3. Add the XMLRPC plugin to MyApp.pm
-You may not always want to run your app at the root of your server or virtual
-host. In this case, it's a simple change to run at any non-root location
-of your choice.
+ use Catalyst qw/-Debug Static::Simple XMLRPC/;
- <Location /myapp>
- SetHandler modperl
- PerlResponseHandler MyApp
- </Location>
-
-When running this way, it is best to make use of the C<uri_for> method in
-Catalyst for constructing correct links.
+4. Add an API controller
-=head4 Static file handling
+ % ./script/myapp_create.pl controller API
-Static files can be served directly by Apache for a performance boost.
+5. Add a XMLRPC redispatch method and an add method with Remote
+attribute to lib/MyApp/Controller/API.pm
- DocumentRoot /var/www/MyApp/root
- <Location /static>
- SetHandler default-handler
- </Location>
-
-This will let all files within root/static be handled directly by Apache. In
-a two-tiered setup, the frontend server should handle static files.
-The configuration to do this on the frontend will vary.
+ sub default : Private {
+ my ( $self, $c ) = @_;
+ $c->xmlrpc;
+ }
-=head2 Don't Repeat Yourself
+ sub add : Remote {
+ my ( $self, $c, $a, $b ) = @_;
+ return $a + $b;
+ }
-DRY is a central principle in Catalyst, yet there is one piece of code
-that is identical in 90% of all Catalyst applications.
+The default action is the entry point for each XMLRPC request. It will
+redispatch every request to methods with Remote attribute in the same
+class.
- sub end : Private {
- my ($self,$c) = @_;
- return 1 if $c->res->body;
- return 1 if $c->response->status =~ /^3\d\d$/;
- $c->forward( 'MyApp::View::TT' );
- }
+The C<add> method is not a traditional action; it has no private or
+public path. Only the XMLRPC dispatcher knows it exists.
-Basically, we want to render a template unless we already have a response,
-or are redirecting.
+6. That's it! You have built your first web service. Let's test it with
+XMLRPCsh.pl (part of SOAP::Lite):
-=head3 Catalyst::Plugin::DefaultEnd to the rescue!
+ % ./script/myapp_server.pl
+ ...
+ % XMLRPCsh.pl http://127.0.0.1:3000/api
+ Usage: method[(parameters)]
+ > add( 1, 2 )
+ --- XMLRPC RESULT ---
+ '3'
-So, rather than doing this again and again, I've made a plugin for you to use.
-sure, it's not much code, but at least it's one function less to worry about.
+=head3 Tip
-Here's how to use it:
+Your return data type is usually auto-detected, but you can easily
+enforce a specific one.
-1. Open up MyApp.pm.
+ sub add : Remote {
+ my ( $self, $c, $a, $b ) = @_;
+ return RPC::XML::int->new( $a + $b );
+ }
+
-2. Add the DefaultEnd plugin like this:
- use Catalyst qw/-Debug DefaultEnd Static::Simple/;
-
-3. There is no step 3 :)
+=head1 Views
-As an added bonus, you can now set dump_info=1 as a url parameter to force
-the end action to die, and display the debug info. Note that this is only
-provided in Debug mode.
+Views pertain to the display of your application. As with models,
+catalyst is uncommonly flexible. The recipes below are just a start.
-By default, DefaultEnd will forward to the first view it can find. If you have
-more than one view, you might want to specifiy the active one, by setting
-$c->config->{view}.
+=head2 Catalyst::View::TT
-If you need to add more things to your end action, you can extend it like this.
+One of the first things you probably want to do when starting a new
+Catalyst application is set up your View. Catalyst doesn't care how you
+display your data; you can choose to generate HTML, PDF files, or plain
+text if you wanted.
- sub end : Private {
- my ( $self, $c ) = @_;
+Most Catalyst applications use a template system to generate their HTML,
+and though there are several template systems available, Template
+Toolkit is probably the most popular.
- ... #code before view
+Once again, the Catalyst developers have done all the hard work, and
+made things easy for the rest of us. Catalyst::View::TT provides the
+interface to Template Toolkit, and provides Helpers which let us set it
+up that much more easily.
- $c->NEXT::end( $c );
-
- ... #code after view
- }
-
-=head2 YAML, YAML, YAML!
+=head3 Creating your View
-When you start a new Catalyst app you configure it directly
-with __PACKAGE__->config, thats ok for development but admins
-will hate you when they have to deploy this.
+Catalyst::View::TT provides two different helpers for us to use: TT and
+TTSite.
- __PACKAGE__->config( name => 'MyApp', 'View::TT' => { EVAL_PERL => 1 } );
+=head4 TT
-You didn't know you could configure your view from the application class, eh? :)
-Thats possible for every component that inherits from Catalyst::Component
-or it's subclasses (Catalyst::Base, Catalyst::Controller, Catalyst::View,
-Catalyst::Model).
+Create a basic Template Toolkit View using the provided helper script:
- __PACKAGE__->config(
- name => 'MyApp',
- 'View::TT' => {
- EVAL_PERL => 1
- },
- 'Controller::Foo' => {
- fool => 'sri'
- }
- );
-
-
- package MyApp::Controller::Foo;
- use base 'Catalyst::Controller';
-
- __PACKAGE__->config( lalala => " can't sing!" );
-
- sub default : Private {
- my ( $self, $c ) = @_;
- $c->res->body( $self->{fool} . $self->{lalala} );
- }
+ script/myapp_create.pl view TT TT
-But back to the topic, lets make our admins happy with this little idiom.
+This will create lib/MyApp/View/MyView.pm, which is going to be pretty
+empty to start. However, it sets everything up that you need to get
+started. You can now define which template you want and forward to your
+view. For instance:
- use YAML ();
-
- __PACKAGE__->config( YAML::LoadFile( __PACKAGE__->path_to('myapp.yml') ) );
+ sub hello : Local {
+ my ( $self, $c ) = @_;
-The C<path_to()> method is a nice little helper that returns paths relative to the
-current application home.
+ $c->stash->{template} = 'hello.tt';
-Thats it, now just create a file C<myapp.yml>.
+ $c->forward( $c->view('TT') );
+ }
- ---
- name: MyApp
- View::TT:
- EVAL_PERL: 1
- Controller::Foo:
- fool: sri
+In practice you wouldn't do the forwarding manually, but would
+use L<Catalyst::Action::RenderView>.
-=head2 Catalyst on shared hosting
+=head4 TTSite
-So, you want to put your Catalyst app out there for the whole world to
-see, but you don't want to break the bank. There is an answer - if you can
-get shared hosting with FastCGI and a shell, you can install your Catalyst
-app. First, run
+Although the TT helper does create a functional, working view, you may
+find yourself having to create the same template files and changing the
+same options every time you create a new application. The TTSite helper
+saves us even more time by creating the basic templates and setting some
+common options for us.
- perl -MCPAN -e shell
+Once again, you can use the helper script:
-and go through the standard CPAN configuration process. Then exit out
-without installing anything. Next, open your .bashrc and add
+ script/myapp_create.pl view TT TTSite
- export PATH=$HOME/local/bin:$HOME/local/script:$PATH
- perlversion=`perl -v | grep 'built for' | awk '{print $4}' | sed -e 's/v//;'`
- export PERL5LIB=$HOME/local/share/perl/$perlversion:$HOME/local/lib/perl/$perlversion:$HOME/local/lib:$PERL5LIB
+This time, the helper sets several options for us in the generated View.
-and log out, then back in again (or run ". .bashrc" if you prefer). Finally,
-edit .cpan/CPAN/MyConfig.pm and add
+ __PACKAGE__->config({
+ CATALYST_VAR => 'Catalyst',
+ INCLUDE_PATH => [
+ MyApp->path_to( 'root', 'src' ),
+ MyApp->path_to( 'root', 'lib' )
+ ],
+ PRE_PROCESS => 'config/main',
+ WRAPPER => 'site/wrapper',
+ ERROR => 'error.tt2',
+ TIMER => 0
+ });
- 'make_install_arg' => qq[SITEPREFIX=$ENV{HOME}/local],
- 'makepl_arg' => qq[INSTALLDIRS=site install_base=$ENV{HOME}/local],
+=over
-Now you can install the modules you need with CPAN as normal, and perl will
-pick them up. Finally, change directory into the root of your virtual host
-and symlink your application's script directory in -
+=item
- cd path/to/mydomain.com
- ln -s ~/lib/MyApp/script script
+INCLUDE_PATH defines the directories that Template Toolkit should search
+for the template files.
-And add the following lines to your .htaccess file (assuming the server is
-setup to handle .pl as fcgi - you may need to rename the script to
-myapp_fastcgi.fcgi and/or use a SetHandler directive) -
+=item
- RewriteEngine On
- RewriteCond %{REQUEST_URI} !^/?script/myapp_fastcgi.pl
- RewriteRule ^(.*)$ script/myapp_fastcgi.pl/$1 [PT,L]
+PRE_PROCESS is used to process configuration options which are common to
+every template file.
-http://mydomain.com/ should now Just Work. Congratulations, now you can
-tell your friends about your new website (or in our case, tell the client
-it's time to pay the invoice :)
+=item
-=head2 Caching
+WRAPPER is a file which is processed with each template, usually used to
+easily provide a common header and footer for every page.
-Catalyst makes it easy to employ several different types of caching to speed
-up your applications.
+=back
-=head3 Cache Plugins
+In addition to setting these options, the TTSite helper also created the
+template and config files for us! In the 'root' directory, you'll notice
+two new directories: src and lib.
-There are three wrapper plugins around common CPAN cache modules:
-Cache::FastMmap, Cache::FileCache, and Cache::Memcached. These can be used
-to cache the result of slow operations.
+Several configuration files in root/lib/config are called by PRE_PROCESS.
-This very page you're viewing makes use of the FileCache plugin to cache the
-rendered XHTML version of the source POD document. This is an ideal
-application for a cache because the source document changes infrequently but
-may be viewed many times.
+The files in root/lib/site are the site-wide templates, called by
+WRAPPER, and display the html framework, control the layout, and provide
+the templates for the header and footer of your page. Using the template
+organization provided makes it much easier to standardize pages and make
+changes when they are (inevitably) needed.
- use Catalyst qw/Cache::FileCache/;
-
- ...
-
- use File::stat;
- sub render_pod : Local {
- my ( self, $c ) = @_;
-
- # the cache is keyed on the filename and the modification time
- # to check for updates to the file.
- my $file = $c->path_to( 'root', '2005', '11.pod' );
- my $mtime = ( stat $file )->mtime;
-
- my $cached_pod = $c->cache->get("$file $mtime");
- if ( !$cached_pod ) {
- $cached_pod = do_slow_pod_rendering();
- # cache the result for 12 hours
- $c->cache->set( "$file $mtime", $cached_pod, '12h' );
- }
- $c->stash->{pod} = $cached_pod;
- }
-
-We could actually cache the result forever, but using a value such as 12 hours
-allows old entries to be automatically expired when they are no longer needed.
+The template files that you will create for your application will go
+into root/src, and you don't need to worry about putting the the <html>
+or <head> sections; just put in the content. The WRAPPER will the rest
+of the page around your template for you.
-=head3 Page Caching
-Another method of caching is to cache the entire HTML page. While this is
-traditionally handled by a front-end proxy server like Squid, the Catalyst
-PageCache plugin makes it trivial to cache the entire output from
-frequently-used or slow actions.
+=head3 $c->stash
-Many sites have a busy content-filled front page that might look something
-like this. It probably takes a while to process, and will do the exact same
-thing for every single user who views the page.
+Of course, having the template system include the header and footer for
+you isn't all that we want our templates to do. We need to be able to
+put data into our templates, and have it appear where and how we want
+it, right? That's where the stash comes in.
- sub front_page : Path('/') {
+In our controllers, we can add data to the stash, and then access it
+from the template. For instance:
+
+ sub hello : Local {
my ( $self, $c ) = @_;
-
- $c->forward( 'get_news_articles' );
- $c->forward( 'build_lots_of_boxes' );
- $c->forward( 'more_slow_stuff' );
-
- $c->stash->{template} = 'index.tt';
- }
-We can add the PageCache plugin to speed things up.
+ $c->stash->{name} = 'Adam';
- use Catalyst qw/Cache::FileCache PageCache/;
-
- sub front_page : Path ('/') {
- my ( $self, $c ) = @_;
-
- $c->cache_page( 300 );
-
- # same processing as above
+ $c->stash->{template} = 'hello.tt';
+
+ $c->forward( $c->view('TT') );
}
-
-Now the entire output of the front page, from <html> to </html>, will be
-cached for 5 minutes. After 5 minutes, the next request will rebuild the
-page and it will be re-cached.
-Note that the page cache is keyed on the page URI plus all parameters, so
-requests for / and /?foo=bar will result in different cache items. Also,
-only GET requests will be cached by the plugin.
+Then, in hello.tt:
-You can even get that front-end Squid proxy to help out by enabling HTTP
-headers for the cached page.
+ <strong>Hello, [% name %]!</strong>
- MyApp->config->{page_cache}->{set_http_headers} = 1;
-
-This would now set the following headers so proxies and browsers may cache
-the content themselves.
+When you view this page, it will display "Hello, Adam!"
- Cache-Control: max-age=($expire_time - time)
- Expires: $expire_time
- Last-Modified: $cache_created_time
-
-=head3 Template Caching
+All of the information in your stash is available, by its name/key, in
+your templates. And your data don't have to be plain, old, boring
+scalars. You can pass array references and hash references, too.
-Template Toolkit provides support for caching compiled versions of your
-templates. To enable this in Catalyst, use the following configuration.
-TT will cache compiled templates keyed on the file mtime, so changes will
-still be automatically detected.
+In your controller:
- package MyApp::View::TT;
-
- use strict;
- use warnings;
- use base 'Catalyst::View::TT';
-
- __PACKAGE__->config(
- COMPILE_DIR => '/tmp/template_cache',
- );
-
- 1;
-
-=head3 More Info
+ sub hello : Local {
+ my ( $self, $c ) = @_;
-See the documentation for each cache plugin for more details and other
-available configuration options.
+ $c->stash->{names} = [ 'Adam', 'Dave', 'John' ];
-L<http://search.cpan.org/dist/Catalyst-Plugin-Cache-FastMmap/lib/Catalyst/Plugin/Cache/FastMmap.pm>
-L<http://search.cpan.org/dist/Catalyst-Plugin-Cache-FileCache/lib/Catalyst/Plugin/Cache/FileCache.pm>
-L<http://search.cpan.org/dist/Catalyst-Plugin-Cache-Memcached/lib/Catalyst/Plugin/Cache/Memcached.pm>
-L<http://search.cpan.org/dist/Catalyst-Plugin-PageCache/lib/Catalyst/Plugin/PageCache.pm>
-L<http://search.cpan.org/dist/Template-Toolkit/lib/Template/Manual/Config.pod#Caching_and_Compiling_Options>
+ $c->stash->{template} = 'hello.tt';
-=head2 L<Catalyst::Plugin::Subrequest>
-
-=head3 Component based sub-requests.
-
-This is actually one of the features we brought over from L<Maypole>. There it
-was called L<Maypole::Plugin::Component>. Basically, the idea is to set up
-new request/response objects, and do an internal request, then return the
-output. It's quite handy for various situations, Simon's example was a
-shopping portal. I'm frequently using it to render parts of my site that I'm
-also rendering with ajax, to avoid duplication of code.
-
-It's quite simple in use. You just call $c->subreq('</public/url>'); (or
-with TT, [% c.subreq('/public/url') %] .) This will localize enough
-of your request/response object so that it shouldn't affect your current
-request, set up a new path/uri, and call the Dispatcher to force a full
-request chain, including begin/end/auto/default and whatever else applies.
-if you don't like 'subreq', theres an alias as well: 'sub_request'.
-
-You can also set up the stash before the request, as well as pass parameters
-to the request like a normal form POST by passing optional hashrefs to the
-subreq method. for example:
-
- my $text=$c->subreq('/foo',{ bar=>$c->stash->{bar} }, {id=>23});
-
-This will dispatch to whatever handles '/foo', with bar in the stash, and
-$c->req->param('id') returning 23. After the request, $text will contain
-whatever's in $c->res->output.
-
-Note, by the way, that the uri path is relative to the application root,
-and not necessesarily the webserver root.
-
-=head2 DBIx::Class as Catalyst Model
-
-=head3 Our Database
-
-This text will show you how to start using DBIx::Class as your model within
-Catalyst. Let's assume, we have a relational set of tables:
-
- shell> sqlite3 myapp.db
- SQLite version 3.2.1
- Enter ".help" for instructions
- sqlite> CREATE TABLE person (
- ...> id INTEGER PRIMARY KEY AUTOINCREMENT,
- ...> name VARCHAR(100)
- ...> );
- sqlite> CREATE TABLE address (
- ...> id INTEGER PRIMARY KEY AUTOINCREMENT,
- ...> person INTEGER REFERENCES person
- ...> address TEXT,
- ...> );
- sqlite> .q
-
-which we want to access from our C<MyApp> Catalyst application.
-
-=head3 Setting up the models
-
-We will cover the more convenient way to start with, and let our models be
-set up automatically. If you want to define your models and their relations
-manually, have a look at C<Catalyst::Model::DBIC::Plain>. We'll concentrate
-on C<Catalyst::Model::DBIC>.
-
-We let a helper do most of the work for us:
-
- shell> script/myapp_create.pl model DBIC DBIC \
- dbi:SQLite:/path/to/myapp.db
- exists "/path/MyApp/script/../lib/MyApp/Model"
- exists "/path/MyApp/script/../t"
- created "/path/MyApp/Model/DBIC.pm"
- created "/path/MyApp/Model/DBIC"
- created "/path/MyApp/Model/DBIC/Address.pm"
- created "/path/MyApp/Model/DBIC/Person.pm"
- created "/path/MyApp/Model/DBIC/SqliteSequence.pm"
- exists "/path/MyApp/script/../t"
- created "/path/MyApp/script/../t/model_DBIC-Address.t"
- exists "/path/MyApp/script/../t"
- created "/path/MyApp/script/../t/model_DBIC-Person.t"
- exists "/path/MyApp/script/../t"
- created "/path/MyApp/script/../t/model_DBIC-SqliteSequence.t"
-
-The base class C<DBIC.pm> that does the setting-up part of the job is set up
-as well as stub files of our modules to extend and the testing environment.
-
-=head3 Table and Relationship Autodetection
-
-If you start your Cat Application up, you can see the loaded tables and
-model components in your debug output:
-
- shell> script/myapp_server.pl
- ...
- [Tue Dec 13 01:20:59 2005] [catalyst] [debug] Loaded
- tables "address person sqlite_sequence"
- ...
- .------------------------------------+----------.
- | Class | Type |
- +------------------------------------+----------+
- | MyApp::Model::DBIC | instance |
- | MyApp::Model::DBIC::Address | class |
- | MyApp::Model::DBIC::Person | class |
- | MyApp::Model::DBIC::SqliteSequence | class |
- | MyApp::Model::DBIC::_db | class |
- '------------------------------------+----------'
- ...
-
-And your models are ready to use! If you change the database schema,
-your models will also change at startup. However, Catalyst will not touch
-your stub model files.
-
-=head3 Using the Models
-
-You can create new objects:
-
- my $person = $c->model( 'DBIC::Person' )->create({
- name => 'Jon Doe',
- });
-
-Or add related objects:
-
- my $adress = $person->add_to_addresses({
- address => 'We wish we knew.',
- });
-
-Search and retrieve from the database:
-
- my $person = $c->model( 'DBIC::Person' )->find(1);
- my $address_iterator = $c->model( 'DBIC::Address' )
- ->search( { address => { like => '%Tokyo%' } } );
+ $c->forward( $c->view('TT') );
+ }
-=head3 More Information
+In hello.tt:
-You can find the documentation of C<Catalyst::Model::DBIC> and its helper
-at
+ [% FOREACH name IN names %]
+ <strong>Hello, [% name %]!</strong><br />
+ [% END %]
-L<http://search.cpan.org/dist/Catalyst-Model-DBIC/>
+This allowed us to loop through each item in the arrayref, and display a
+line for each name that we have.
-For information concerning DBIx::Class please visit the documentation and
-Intro on CPAN:
+This is the most basic usage, but Template Toolkit is quite powerful,
+and allows you to truly keep your presentation logic separate from the
+rest of your application.
-L<http://search.cpan.org/dist/DBIx-Class/>
-L<http://search.cpan.org/dist/DBIx-Class/lib/DBIx/Class/Manual/Intro.pod>
+=head3 $c->uri_for()
-or its own Wiki
+One of my favorite things about Catalyst is the ability to move an
+application around without having to worry that everything is going to
+break. One of the areas that used to be a problem was with the http
+links in your template files. For example, suppose you have an
+application installed at http://www.domain.com/Calendar. The links point
+to "/Calendar", "/Calendar/2005", "/Calendar/2005/10", etc. If you move
+the application to be at http://www.mydomain.com/Tools/Calendar, then
+all of those links will suddenly break.
-L<http://dbix-class.shadowcatsystems.co.uk/>
+That's where $c->uri_for() comes in. This function will merge its
+parameters with either the base location for the app, or its current
+namespace. Let's take a look at a couple of examples.
-and of course, you can find support on irc.perl.org#catalyst and
-irc.perl.org#dbix-class.
+In your template, you can use the following:
-=head2 Authentication/Authorization
+ <a href="[% c.uri_for('/login') %]">Login Here</a>
-This is done in several steps:
+Although the parameter starts with a forward slash, this is relative to the application root, not the webserver root. This is important to remember. So, if your application is installed at http://www.domain.com/Calendar, then the link would be http://www.mydomain.com/Calendar/Login. If you move your application to a different domain or path, then that link will still be correct.
-=over 4
+Likewise,
-=item Verification
+ <a href="[% c.uri_for('2005','10', '24') %]">October, 24 2005</a>
-Getting the user to identify themselves, by giving you some piece of
-information known only to you and the user. Then you can assume that the user
-is who they say they are. This is called B<credential verification>.
+The first parameter does NOT have a forward slash, and so it will be relative to the current namespace. If the application is installed at http://www.domain.com/Calendar. and if the template is called from MyApp::Controller::Display, then the link would become http://www.domain.com/Calendar/Display/2005/10/24.
-=item Authorization
+Once again, this allows you to move your application around without having to worry about broken links. But there's something else, as well. Since the links are generated by uri_for, you can use the same template file by several different controllers, and each controller will get the links that its supposed to. Since we believe in Don't Repeat Yourself, this is particularly helpful if you have common elements in your site that you want to keep in one file.
-Making sure the user only accesses functions you want them to access. This is
-done by checking the verified users data against your internal list of groups,
-or allowed persons for the current page.
+Further Reading:
-=back
+L<http://search.cpan.org/perldoc?Catalyst>
-=head3 Modules
+L<http://search.cpan.org/perldoc?Catalyst%3A%3AView%3A%3ATT>
-The Catalyst Authentication system is made up of many interacting modules, to
-give you the most flexibility possible.
+L<http://search.cpan.org/perldoc?Template>
-=head4 Credential verifiers
+=head2 Adding RSS feeds
-A Credential module tables the user input, and passes it to a Store, or some
-other system, for verification. Typically, a user object is created by either
-this module or the Store and made accessible by a C<< $c->user >> call.
+Adding RSS feeds to your Catalyst applications is simple. We'll see two
+different aproaches here, but the basic premise is that you forward to
+the normal view action first to get the objects, then handle the output
+differently.
-Examples:
+=head3 Using TT templates
- Password - Simple username/password checking.
- HTTPD - Checks using basic HTTP auth.
- TypeKey - Check using the typekey system.
+This is the aproach used in Agave (L<http://dev.rawmode.org/>).
-=head3 Storage backends
+ sub rss : Local {
+ my ($self,$c) = @_;
+ $c->forward('view');
+ $c->stash->{template}='rss.tt';
+ }
-A Storage backend contains the actual data representing the users. It is
-queried by the credential verifiers. Updating the store is not done within
-this system, you will need to do it yourself.
+Then you need a template. Here's the one from Agave:
-Examples:
+ <?xml version="1.0" encoding="UTF-8"?>
+ <rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
+ <channel>
+ <title>[ [% blog.name || c.config.name || "Agave" %] ] RSS Feed</title>
+ <link>[% base %]</link>
+ <description>Recent posts</description>
+ <language>en-us</language>
+ <ttl>40</ttl>
+ [% WHILE (post = posts.next) %]
+ <item>
+ <title>[% post.title %]</title>
+ <description>[% post.formatted_teaser|html%]</description>
+ <pubDate>[% post.pub_date %]</pubDate>
+ <guid>[% post.full_uri %]</guid>
+ <link>[% post.full_uri %]</link>
+ <dc:creator>[% post.author.screenname %]</dc:creator>
+ </item>
+ [% END %]
+ </channel>
+ </rss>
- DBIC - Storage using a database.
- Minimal - Storage using a simple hash (for testing).
+=head3 Using XML::Feed
-=head3 User objects
+A more robust solution is to use XML::Feed, as was done in the Catalyst
+Advent Calendar. Assuming we have a C<view> action that populates
+'entries' with some DBIx::Class iterator, the code would look something
+like this:
-A User object is created by either the storage backend or the credential
-verifier, and filled with the retrieved user information.
+ sub rss : Local {
+ my ($self,$c) = @_;
+ $c->forward('view'); # get the entries
-Examples:
+ my $feed = XML::Feed->new('RSS');
+ $feed->title( $c->config->{name} . ' RSS Feed' );
+ $feed->link( $c->req->base ); # link to the site.
+ $feed->description('Catalyst advent calendar'); Some description
- Hash - A simple hash of keys and values.
+ # Process the entries
+ while( my $entry = $c->stash->{entries}->next ) {
+ my $feed_entry = XML::Feed::Entry->new('RSS');
+ $feed_entry->title($entry->title);
+ $feed_entry->link( $c->uri_for($entry->link) );
+ $feed_entry->issued( DateTime->from_epoch(epoch => $entry->created) );
+ $feed->add_entry($feed_entry);
+ }
+ $c->res->body( $feed->as_xml );
+ }
-=head3 ACL authorization
+A little more code in the controller, but with this approach you're
+pretty sure to get something that validates.
-ACL stands for Access Control List. The ACL plugin allows you to regulate
-access on a path by path basis, by listing which users, or roles, have access
-to which paths.
+Note that for both of the above aproaches, you'll need to set the
+content type like this:
-=head3 Roles authorization
+ $c->res->content_type('application/rss+xml');
-Authorization by roles is for assigning users to groups, which can then be
-assigned to ACLs, or just checked when needed.
+=head3 Final words
-=head3 Logging in
+You could generalize the second variant easily by replacing 'RSS' with a
+variable, so you can generate Atom feeds with the same code.
-When you have chosen your modules, all you need to do is call the C<<
-$c->login >> method. If called with no parameters, it will try to find
-suitable parameters, such as B<username> and B<password>, or you can pass it
-these values.
+Now, go ahead and make RSS feeds for all your stuff. The world *needs*
+updates on your goldfish!
-=head3 Checking roles
+=head2 Forcing the browser to download content
-Role checking is done by using the C<< $c->check_user_roles >> method, this will
-check using the currently logged in user (via C<< $c->user >>). You pass it
-the name of a role to check, and it returns true if the user is a member.
+Sometimes you need your application to send content for download. For
+example, you can generate a comma-separated values (CSV) file for your
+users to download and import into their spreadsheet program.
-=head3 EXAMPLE
+Let's say you have an C<Orders> controller which generates a CSV file
+in the C<export> action (i.e., C<http://localhost:3000/orders/export>):
- use Catalyst qw/Authentication
- Authentication::Credential::Password
- Authentication::Store::Htpasswd
- Authorization::Roles/;
+ sub export : Local Args(0) {
+ my ( $self, $c ) = @_;
- __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
+ # In a real application, you'd generate this from the database
+ my $csv = "1,5.99\n2,29.99\n3,3.99\n";
- sub login : Local {
- my ($self, $c) = @_;
+ $c->res->content_type('text/comma-separated-values');
+ $c->res->body($csv);
+ }
- if ( my $user = $c->req->param("user")
- and my $password = $c->req->param("password") )
- {
- if ( $c->login( $user, $password ) ) {
- $c->res->body( "hello " . $c->user->name );
- } else {
- # login incorrect
- }
- }
- else {
- # invalid form input
- }
- }
+Normally the browser uses the last part of the URI to generate a
+filename for data it cannot display. In this case your browser would
+likely ask you to save a file named C<export>.
- sub restricted : Local {
- my ( $self, $c ) = @_;
+Luckily you can have the browser download the content with a specific
+filename by setting the C<Content-Disposition> header:
- $c->detach("unauthorized")
- unless $c->check_user_roles( "admin" );
+ my $filename = 'Important Orders.csv';
+ $c->res->header('Content-Disposition', qq[attachment; filename="$filename"]);
- # do something restricted here
- }
+Note the use of quotes around the filename; this ensures that any
+spaces in the filename are handled by the browser.
+Put this right before calling C<< $c->res->body >> and your browser
+will download a file named C<Important Orders.csv> instead of
+C<export>.
-=head3 More information
+You can also use this to have the browser download content which it
+normally displays, such as JPEG images or even HTML. Just be sure to
+set the appropriate content type and disposition.
-L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authentication> has a longer explanation.
-=head2 Sessions
+=head1 Controllers
-When you have your users identified, you will want to somehow remember that
-fact, to save them from having to identify themselves for every single
-page. One way to do this is to send the username and password parameters in
-every single page, but that's ugly, and won't work for static pages.
+Controllers are the main point of communication between the web server
+and your application. Here we explore some aspects of how they work.
-Sessions are a method of saving data related to some transaction, and giving
-the whole collection a single ID. This ID is then given to the user to return
-to us on every page they visit while logged in. The usual way to do this is
-using a browser cookie.
+=head2 Extending RenderView (formerly DefaultEnd)
-Catalyst uses two types of plugins to represent sessions:
+The recommended approach for an C<end> action is to use
+L<Catalyst::Action::RenderView> (taking the place of
+L<Catalyst::Plugin::DefaultEnd>), which does what you usually need.
+However there are times when you need to add a bit to it, but don't want
+to write your own C<end> action.
-=head3 State
+You can extend it like this:
-A State module is used to keep track of the state of the session between the
-users browser, and your application.
+To add something to an C<end> action that is called before rendering
+(this is likely to be what you want), simply place it in the C<end>
+method:
-A common example is the Cookie state module, which sends the browser a cookie
-containing the session ID. It will use default value for the cookie name and
-domain, so will "just work" when used.
+ sub end : ActionClass('RenderView') {
+ my ( $self, $c ) = @_;
+ # do stuff here; the RenderView action is called afterwards
+ }
-=head3 Store
+To add things to an C<end> action that are called I<after> rendering,
+you can set it up like this:
-A Store module is used to hold all the data relating to your session, for
-example the users ID, or the items for their shopping cart. You can store data
-in memory (FastMmap), in a file (File) or in a database (DBI).
+ sub render : ActionClass('RenderView') { }
-=head3 Authentication magic
+ sub end : Private {
+ my ( $self, $c ) = @_;
+ $c->forward('render');
+ # do stuff here
+ }
+
+=head2 Action Types
-If you have included the session modules in your application, the
-Authentication modules will automagically use your session to save and
-retrieve the user data for you.
+=head3 Introduction
-=head3 Using a session
+A Catalyst application is driven by one or more Controller modules. There are
+a number of ways that Catalyst can decide which of the methods in your
+controller modules it should call. Controller methods are also called actions,
+because they determine how your catalyst application should (re-)act to any
+given URL. When the application is started up, catalyst looks at all your
+actions, and decides which URLs they map to.
-Once the session modules are loaded, the session is available as C<<
-$c->session >>, and can be writen to and read from as a simple hash reference.
+=head3 Type attributes
-=head3 EXAMPLE
+Each action is a normal method in your controller, except that it has an
+L<attribute|http://search.cpan.org/~nwclark/perl-5.8.7/lib/attributes.pm>
+attached. These can be one of several types.
- use Catalyst qw/
- Session
- Session::Store::FastMmap
- Session::State::Cookie
- /;
+Assume our Controller module starts with the following package declaration:
+
+ package MyApp::Controller::Buckets;
+and we are running our application on localhost, port 3000 (the test
+server default).
- ## Write data into the session
+=over 4
+
+=item Path
- sub add_item : Local {
- my ( $self, $c ) = @_;
+A Path attribute also takes an argument, this can be either a relative
+or an absolute path. A relative path will be relative to the controller
+namespace, an absolute path will represent an exact matching URL.
- my $item_id = $c->req->param("item");
+ sub my_handles : Path('handles') { .. }
- push @{ $c->session->{items} }, $item_id;
+becomes
- }
+ http://localhost:3000/buckets/handles
- ## A page later we retrieve the data from the session:
+and
- sub get_items : Local {
- my ( $self, $c ) = @_;
+ sub my_handles : Path('/handles') { .. }
- $c->stash->{items_to_display} = $c->session->{items};
+becomes
- }
+ http://localhost:3000/handles
+=item Local
-=head3 More information
+When using a Local attribute, no parameters are needed, instead, the name of
+the action is matched in the URL. The namespaces created by the name of the
+controller package is always part of the URL.
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session>
+ sub my_handles : Local { .. }
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-Cookie>
+becomes
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-URI>
+ http://localhost:3000/buckets/my_handles
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-FastMmap>
+=item Global
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-File>
+A Global attribute is similar to a Local attribute, except that the namespace
+of the controller is ignored, and matching starts at root.
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-DBI>
+ sub my_handles : Global { .. }
-=head2 Adding RSS feeds
+becomes
-Adding RSS feeds to your stuff in Catalyst is really simple. I'll show two
-different aproaches here, but the basic premise is that you forward to the
-normal view action first to get the objects, then handle the output differently
+ http://localhost:3000/my_handles
-=head3 Using TT templates
+=item Regex
-This is the aproach we chose in Agave (L<http://dev.rawmode.org/>).
+By now you should have figured that a Regex attribute is just what it sounds
+like. This one takes a regular expression, and matches starting from
+root. These differ from the rest as they can match multiple URLs.
- sub rss : Local {
- my ($self,$c) = @_;
- $c->forward('view');
- $c->stash->{template}='rss.tt';
- }
+ sub my_handles : Regex('^handles') { .. }
-Then you need a template. Here's the one from Agave:
-L<http://svn.rawmode.org/repos/Agave/trunk/root/base/blog/rss.tt>
+matches
-As you can see, it's pretty simple.
+ http://localhost:3000/handles
-=head3 Using XML::Feed
+and
-However, a more robust solution is to use XML::Feed, as we've done in this
-Advent Calendar. Assuming we have a 'view' action that populates 'entries'
-with some DBIx::Class/Class::DBI iterator, the code would look something like
-this:
+ http://localhost:3000/handles_and_other_parts
- sub rss : Local {
- my ($self,$c) = @_;
- $c->forward('view'); # get the entries
+etc.
- my $feed = XML::Feed->new('RSS');
- $feed->title( $c->config->{name} . ' RSS Feed' );
- $feed->link( $c->req->base ); # link to the site.
- $feed->description('Catalyst advent calendar'); Some description
+=item LocalRegex
- # Process the entries
- while( my $entry=$c->stash->{entries}->next ) {
- my $feed_entry = XML::Feed::Entry->new('RSS');
- $feed_entry->title($entry->title);
- $feed_entry->link( $c->uri_for($entry->link) );
- $feed_entry->issued( DateTime->from_epoch(epoch => $entry->created) );
- $feed->add_entry($feed_entry);
- }
- $c->res->body( $feed->as_xml );
- }
+A LocalRegex is similar to a Regex, except it only matches below the current
+controller namespace.
+ sub my_handles : LocalRegex(^handles') { .. }
-A little more code in the controller, but with this approach you're pretty sure
-to get something that validates. One little note regarding that tho, for both
-of the above aproaches, you'll need to set the content type like this:
+matches
- $c->res->content_type('application/rss+xml');
+ http://localhost:3000/buckets/handles
-=head2 Final words
+and
-Note that you could generalize the second variant easily by replacing 'RSS'
-with a variable, so you can generate Atom feeds with the same code.
+ http://localhost:3000/buckets/handles_and_other_parts
-Now, go ahead and make RSS feeds for all your stuff. The world *needs* updates
-on your goldfish!
+etc.
-=head2 FastCGI Deployment
+=item Private
-As a companion to Day 7's mod_perl article, today's article is about
-production FastCGI deployment.
+Last but not least, there is the Private attribute, which allows you to create
+your own internal actions, which can be forwarded to, but won't be matched as
+URLs.
-=head3 Pros
+ sub my_handles : Private { .. }
-=head4 Speed
+becomes nothing at all..
-FastCGI performs equally as well as mod_perl. Don't let the 'CGI' fool you;
-your app runs as multiple persistent processes ready to receive connections
-from the web server.
+Catalyst also predefines some special Private actions, which you can override,
+these are:
-=head4 App Server
+=over 4
-When using external FastCGI servers, your application runs as a standalone
-application server. It may be restarted independently from the web server.
-This allows for a more robust environment and faster reload times when
-pushing new app changes. The frontend server can even be configured to
-display a friendly "down for maintenance" page while the application is
-restarting.
+=item default
-=head4 Load-balancing
+The default action will be called, if no other matching action is found. If
+you don't have one of these in your namespace, or any sub part of your
+namespace, you'll get an error page instead. If you want to find out where it
+was the user was trying to go, you can look in the request object using
+C<< $c->req->path >>.
-You can launch your application on multiple backend servers and allow the
-frontend web server to load-balance between all of them. And of course, if
-one goes down, your app continues to run fine.
+ sub default : Private { .. }
-=head4 Multiple versions of the same app
+works for all unknown URLs, in this controller namespace, or every one if put
+directly into MyApp.pm.
-Each FastCGI application is a separate process, so you can run different
-versions of the same app on a single server.
+=item index
-=head4 Can run with threaded Apache
+The index action is called when someone tries to visit the exact namespace of
+your controller. If index, default and matching Path actions are defined, then
+index will be used instead of default and Path.
-Since your app is not running inside of Apache, the faster mpm_worker module
-can be used without worrying about the thread safety of your application.
+ sub index : Private { .. }
-=head3 Cons
+becomes
-=head4 More complex environment
+ http://localhost:3000/buckets
-With FastCGI, there are more things to monitor and more processes running
-than when using mod_perl.
+=item begin
-=head3 Setup
+The begin action is called at the beginning of every request involving this
+namespace directly, before other matching actions are called. It can be used
+to set up variables/data for this particular part of your app. A single begin
+action is called, its always the one most relevant to the current namespace.
-=head4 1. Install Apache with mod_fastcgi
+ sub begin : Private { .. }
-mod_fastcgi for Apache is a third party module, and can be found at
-L<http://www.fastcgi.com/>. It is also packaged in many distributions, for
-example, libapache2-mod-fastcgi in Debian.
+is called once when
-=head4 2. Configure your application
+ http://localhost:3000/bucket/(anything)?
- # Serve static content directly
- DocumentRoot /var/www/MyApp/root
- Alias /static /var/www/MyApp/root/static
+is visited.
- FastCgiServer /var/www/MyApp/script/myapp_fastcgi.pl -processes 3
- Alias /myapp/ /var/www/MyApp/script/myapp_fastcgi.pl/
-
- # Or, run at the root
- Alias / /var/www/MyApp/script/myapp_fastcgi.pl/
-
-The above commands will launch 3 app processes and make the app available at
-/myapp/
+=item end
-=head3 Standalone server mode
+Like begin, this action is always called for the namespace it is in, after
+every other action has finished. It is commonly used to forward processing to
+the View component. A single end action is called, its always the one most
+relevant to the current namespace.
-While not as easy as the previous method, running your app as an external
-server gives you much more flexibility.
-First, launch your app as a standalone server listening on a socket.
+ sub end : Private { .. }
- script/myapp_fastcgi.pl -l /tmp/myapp.socket -n 5 -p /tmp/myapp.pid -d
-
-You can also listen on a TCP port if your web server is not on the same
-machine.
+is called once after any actions when
- script/myapp_fastcgi.pl -l :8080 -n 5 -p /tmp/myapp.pid -d
-
-You will probably want to write an init script to handle starting/stopping
-of the app using the pid file.
+ http://localhost:3000/bucket/(anything)?
-Now, we simply configure Apache to connect to the running server.
+is visited.
- # 502 is a Bad Gateway error, and will occur if the backend server is down
- # This allows us to display a friendly static page that says "down for
- # maintenance"
- Alias /_errors /var/www/MyApp/root/error-pages
- ErrorDocument 502 /_errors/502.html
+=item auto
- FastCgiExternalServer /tmp/myapp -socket /tmp/myapp.socket
- Alias /myapp/ /tmp/myapp/
-
- # Or, run at the root
- Alias / /tmp/myapp/
-
-=head3 More Info
+Lastly, the auto action is magic in that B<every> auto action in
+the chain of paths up to and including the ending namespace, will be
+called. (In contrast, only one of the begin/end/default actions will be
+called, the relevant one).
-Lots more information is available in the new and expanded FastCGI docs that
-will be part of Catalyst 5.62. For now you may read them here:
-L<http://dev.catalyst.perl.org/file/trunk/Catalyst/lib/Catalyst/Engine/FastCGI.pm>
+ package MyApp.pm;
+ sub auto : Private { .. }
-=head2 Catalyst::View::TT
+and
-One of the first things you probably want to do when starting a new Catalyst application is set up your View. Catalyst doesn't care how you display your data; you can choose to generate HTML, PDF files, or plain text if you wanted.
+ sub auto : Private { .. }
-Most Catalyst applications use a template system to generate their HTML, and though there are several template systems available, Template Toolkit is probably the most popular.
+will both be called when visiting
-Once again, the Catalyst developers have done all the hard work, and made things easy for the rest of us. Catalyst::View::TT provides the interface to Template Toolkit, and provides Helpers which let us set it up that much more easily.
+ http://localhost:3000/bucket/(anything)?
-=head3 Creating your View
+=back
-Catalyst::View::TT provides two different helpers for use to use: TT and TTSite.
+=back
-=head4 TT
+=head3 A word of warning
-Create a basic Template Toolkit View using the provided helper script:
+Due to possible namespace conflicts with Plugins, it is advised to only put the
+pre-defined Private actions in your main MyApp.pm file, all others should go
+in a Controller module.
- script/myapp_create.pl view TT TT
+=head3 More Information
-This will create lib/MyApp/View/MyView.pm, which is going to be pretty empty to start. However, it sets everything up that you need to get started. You can now define which template you want and forward to your view. For instance:
+L<http://search.cpan.org/author/SRI/Catalyst-5.61/lib/Catalyst/Manual/Intro.pod>
- sub hello : Local {
- my ( $self, $c ) = @_;
+L<http://dev.catalyst.perl.org/wiki/FlowChart>
- $c->stash->{template} = 'hello.tt';
+=head2 Component-based Subrequests
- $c->forward( $c->view('TT') );
- }
+See L<Catalyst::Plugin::SubRequest>.
-In most cases, you will put the $c->forward into end(), and then you would only have to define which template you want to use. The S<DefaultEnd> plugin discussed on Day 8 is also commonly used.
+=head2 File uploads
-=head4 TTSite
+=head3 Single file upload with Catalyst
-Although the TT helper does create a functional, working view, you may find yourself having to create the same template files and changing the same options every time you create a new application. The TTSite helper saves us even more time by creating the basic templates and setting some common options for us.
+To implement uploads in Catalyst, you need to have a HTML form similar to
+this:
-Once again, you can use the helper script:
+ <form action="/upload" method="post" enctype="multipart/form-data">
+ <input type="hidden" name="form_submit" value="yes">
+ <input type="file" name="my_file">
+ <input type="submit" value="Send">
+ </form>
- script/myapp_create.pl view TT TTSite
+It's very important not to forget C<enctype="multipart/form-data"> in
+the form.
-This time, the helper sets several options for us in the generated View.
+Catalyst Controller module 'upload' action:
- __PACKAGE__->config({
- CATALYST_VAR => 'Catalyst',
- INCLUDE_PATH => [
- MyApp->path_to( 'root', 'src' ),
- MyApp->path_to( 'root', 'lib' )
- ],
- PRE_PROCESS => 'config/main',
- WRAPPER => 'site/wrapper',
- ERROR => 'error.tt2',
- TIMER => 0
- });
+ sub upload : Global {
+ my ($self, $c) = @_;
-=over
+ if ( $c->request->parameters->{form_submit} eq 'yes' ) {
-=item
-INCLUDE_PATH defines the directories that Template Toolkit should search for the template files.
+ if ( my $upload = $c->request->upload('my_file') ) {
-=item
-PRE_PROCESS is used to process configuration options which are common to every template file.
+ my $filename = $upload->filename;
+ my $target = "/tmp/upload/$filename";
-=item
-WRAPPER is a file which is processed with each template, usually used to easily provide a common header and footer for every page.
+ unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
+ die( "Failed to copy '$filename' to '$target': $!" );
+ }
+ }
+ }
-=back
+ $c->stash->{template} = 'file_upload.html';
+ }
-In addition to setting these options, the TTSite helper also created the template and config files for us! In the 'root' directory, you'll notice two new directories: src and lib.
+=head3 Multiple file upload with Catalyst
-Several configuration files in root/lib/config are called by PRE_PROCESS.
+Code for uploading multiple files from one form needs a few changes:
-The files in root/lib/site are the site-wide templates, called by WRAPPER, and display the html framework, control the layout, and provide the templates for the header and footer of your page. Using the template organization provided makes it much easier to standardize pages and make changes when they are (inevitably) needed.
+The form should have this basic structure:
-The template files that you will create for your application will go into root/src, and you don't need to worry about putting the the <html> or <head> sections; just put in the content. The WRAPPER will the rest of the page around your template for you.
+ <form action="/upload" method="post" enctype="multipart/form-data">
+ <input type="hidden" name="form_submit" value="yes">
+ <input type="file" name="file1" size="50"><br>
+ <input type="file" name="file2" size="50"><br>
+ <input type="file" name="file3" size="50"><br>
+ <input type="submit" value="Send">
+ </form>
-=head2 $c->stash
+And in the controller:
-Of course, having the template system include the header and footer for you isn't all that we want our templates to do. We need to be able to put data into our templates, and have it appear where and how we want it, right? That's where the stash comes in.
+ sub upload : Local {
+ my ($self, $c) = @_;
-In our controllers, we can add data to the stash, and then access it from the template. For instance:
+ if ( $c->request->parameters->{form_submit} eq 'yes' ) {
- sub hello : Local {
- my ( $self, $c ) = @_;
+ for my $field ( $c->req->upload ) {
- $c->stash->{name} = 'Adam';
+ my $upload = $c->req->upload($field);
+ my $filename = $upload->filename;
+ my $target = "/tmp/upload/$filename";
- $c->stash->{template} = 'hello.tt';
+ unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
+ die( "Failed to copy '$filename' to '$target': $!" );
+ }
+ }
+ }
- $c->forward( $c->view('TT') );
+ $c->stash->{template} = 'file_upload.html';
}
-Then, in hello.tt:
+C<for my $field ($c-E<gt>req->upload)> loops automatically over all file
+input fields and gets input names. After that is basic file saving code,
+just like in single file upload.
- <strong>Hello, [% name %]!</strong>
+Notice: C<die>ing might not be what you want to do, when an error
+occurs, but it works as an example. A better idea would be to store
+error C<$!> in $c->stash->{error} and show a custom error template
+displaying this message.
-When you view this page, it will display "Hello, Adam!"
+For more information about uploads and usable methods look at
+L<Catalyst::Request::Upload> and L<Catalyst::Request>.
-All of the information in your stash is available, by its name/key, in your templates. And your data doesn't have to be plain, old, boring scalars. You can pass array references and hash references, too.
+=head2 Forwarding with arguments
-In your controller:
+Sometimes you want to pass along arguments when forwarding to another
+action. As of version 5.30, arguments can be passed in the call to
+C<forward>; in earlier versions, you can manually set the arguments in
+the Catalyst Request object:
- sub hello : Local {
- my ( $self, $c ) = @_;
+ # version 5.30 and later:
+ $c->forward('/wherever', [qw/arg1 arg2 arg3/]);
- $c->stash->{names} = [ 'Adam', 'Dave', 'John' ];
+ # pre-5.30
+ $c->req->args([qw/arg1 arg2 arg3/]);
+ $c->forward('/wherever');
- $c->stash->{template} = 'hello.tt';
+(See the L<Catalyst::Manual::Intro> Flow_Control section for more
+information on passing arguments via C<forward>.)
- $c->forward( $c->view('TT') );
- }
-In hello.tt:
+=head1 Deployment
- [% FOREACH name IN names %]
- <strong>Hello, [% name %]!</strong><br />
- [% END %]
+The recipes below describe aspects of the deployment process,
+including web server engines and tips to improve application efficiency.
-This allowed us to loop through each item in the arrayref, and display a line for each name that we have.
+=head2 mod_perl Deployment
-This is the most basic usage, but Template Toolkit is quite powerful, and allows you to truly keep your presentation logic separate from the rest of your application.
+mod_perl is the best solution for many applications, but we'll list some pros
+and cons so you can decide for yourself. The other production deployment
+option is FastCGI, for which see below.
-=head3 $c->uri_for()
+=head3 Pros
-One of my favorite things about Catalyst is the ability to move an application around without having to worry that everything is going to break. One of the areas that used to be a problem was with the http links in your template files. For example, suppose you have an application installed at http://www.domain.com/Calendar. The links point to "/Calendar", "/Calendar/2005", "/Calendar/2005/10", etc. If you move the application to be at http://www.mydomain.com/Tools/Calendar, then all of those links will suddenly break.
+=head4 Speed
-That's where $c->uri_for() comes in. This function will merge its parameters with either the base location for the app, or its current namespace. Let's take a look at a couple of examples.
+mod_perl is very fast and your app will benefit from being loaded in memory
+within each Apache process.
-In your template, you can use the following:
+=head4 Shared memory for multiple apps
- <a href="[% c.uri_for('/login') %]">Login Here</a>
+If you need to run several Catalyst apps on the same server, mod_perl will
+share the memory for common modules.
-Although the parameter starts with a forward slash, this is relative to the application root, not the webserver root. This is important to remember. So, if your application is installed at http://www.domain.com/Calendar, then the link would be http://www.mydomain.com/Calendar/Login. If you move your application to a different domain or path, then that link will still be correct.
+=head3 Cons
-Likewise,
+=head4 Memory usage
- <a href="[% c.uri_for('2005','10', '24') %]">October, 24 2005</a>
+Since your application is fully loaded in memory, every Apache process will
+be rather large. This means a large Apache process will be tied up while
+serving static files, large files, or dealing with slow clients. For this
+reason, it is best to run a two-tiered web architecture with a lightweight
+frontend server passing dynamic requests to a large backend mod_perl
+server.
-The first parameter does NOT have a forward slash, and so it will be relative to the current namespace. If the application is installed at http://www.domain.com/Calendar. and if the template is called from MyApp::Controller::Display, then the link would become http://www.domain.com/Calendar/Display/2005/10/24.
+=head4 Reloading
-Once again, this allows you to move your application around without having to worry about broken links. But there's something else, as well. Since the links are generated by uri_for, you can use the same template file by several different controllers, and each controller will get the links that its supposed to. Since we believe in Don't Repeat Yourself, this is particularly helpful if you have common elements in your site that you want to keep in one file.
+Any changes made to the core code of your app require a full Apache restart.
+Catalyst does not support Apache::Reload or StatINC. This is another good
+reason to run a frontend web server where you can set up an
+C<ErrorDocument 502> page to report that your app is down for maintenance.
-Further Reading:
+=head4 Cannot run multiple versions of the same app
-L<http://search.cpan.org/perldoc?Catalyst>
+It is not possible to run two different versions of the same application in
+the same Apache instance because the namespaces will collide.
-L<http://search.cpan.org/perldoc?Catalyst%3A%3AView%3A%3ATT>
+=head4 Setup
-L<http://search.cpan.org/perldoc?Template>
+Now that we have that out of the way, let's talk about setting up mod_perl
+to run a Catalyst app.
-=head2 Testing
+=head4 1. Install Catalyst::Engine::Apache
-Catalyst provides a convenient way of testing your application during
-development and before deployment in a real environment.
+You should install the latest versions of both Catalyst and
+Catalyst::Engine::Apache. The Apache engines were separated from the
+Catalyst core in version 5.50 to allow for updates to the engine without
+requiring a new Catalyst release.
-C<Catalyst::Test> makes it possible to run the same tests both locally
-(without an external daemon) and against a remote server via HTTP.
+=head4 2. Install Apache with mod_perl
-=head3 Tests
+Both Apache 1.3 and Apache 2 are supported, although Apache 2 is highly
+recommended. With Apache 2, make sure you are using the prefork MPM and not
+the worker MPM. The reason for this is that many Perl modules are not
+thread-safe and may have problems running within the threaded worker
+environment. Catalyst is thread-safe however, so if you know what you're
+doing, you may be able to run using worker.
-Let's examine a skeleton application's C<t/> directory:
+In Debian, the following commands should get you going.
- mundus:~/MyApp chansen$ ls -l t/
- total 24
- -rw-r--r-- 1 chansen chansen 95 18 Dec 20:50 01app.t
- -rw-r--r-- 1 chansen chansen 190 18 Dec 20:50 02pod.t
- -rw-r--r-- 1 chansen chansen 213 18 Dec 20:50 03podcoverage.t
+ apt-get install apache2-mpm-prefork
+ apt-get install libapache2-mod-perl2
-=over 4
+=head4 3. Configure your application
-=item C<01app.t>
+Every Catalyst application will automagically become a mod_perl handler
+when run within mod_perl. This makes the configuration extremely easy.
+Here is a basic Apache 2 configuration.
-Verifies that the application loads, compiles, and returns a successful
-response.
+ PerlSwitches -I/var/www/MyApp/lib
+ PerlModule MyApp
+
+ <Location />
+ SetHandler modperl
+ PerlResponseHandler MyApp
+ </Location>
-=item C<02pod.t>
+The most important line here is C<PerlModule MyApp>. This causes mod_perl
+to preload your entire application into shared memory, including all of your
+controller, model, and view classes and configuration. If you have -Debug
+mode enabled, you will see the startup output scroll by when you first
+start Apache.
-Verifies that all POD is free from errors. Only executed if the C<TEST_POD>
-environment variable is true.
+For an example Apache 1.3 configuration, please see the documentation for
+L<Catalyst::Engine::Apache::MP13>.
-=item C<03podcoverage.t>
+=head3 Test It
-Verifies that all methods/functions have POD coverage. Only executed if the
-C<TEST_POD> environment variable is true.
+That's it, your app is now a full-fledged mod_perl application! Try it out
+by going to http://your.server.com/.
-=back
+=head3 Other Options
-=head3 Creating tests
+=head4 Non-root location
- mundus:~/MyApp chansen$ cat t/01app.t | perl -ne 'printf( "%2d %s", $., $_ )'
- 1 use Test::More tests => 2;
- 2 use_ok( Catalyst::Test, 'MyApp' );
- 3
- 4 ok( request('/')->is_success );
+You may not always want to run your app at the root of your server or virtual
+host. In this case, it's a simple change to run at any non-root location
+of your choice.
-The first line declares how many tests we are going to run, in this case
-two. The second line tests and loads our application in test mode. The
-fourth line verifies that our application returns a successful response.
+ <Location /myapp>
+ SetHandler modperl
+ PerlResponseHandler MyApp
+ </Location>
+
+When running this way, it is best to make use of the C<uri_for> method in
+Catalyst for constructing correct links.
-C<Catalyst::Test> exports two functions, C<request> and C<get>. Each can
-take three different arguments:
+=head4 Static file handling
-=over 4
+Static files can be served directly by Apache for a performance boost.
-=item A string which is a relative or absolute URI.
+ DocumentRoot /var/www/MyApp/root
+ <Location /static>
+ SetHandler default-handler
+ </Location>
+
+This will let all files within root/static be handled directly by Apache. In
+a two-tiered setup, the frontend server should handle static files.
+The configuration to do this on the frontend will vary.
- request('/my/path');
- request('http://www.host.com/my/path');
+=head2 Catalyst on shared hosting
-=item An instance of C<URI>.
+So, you want to put your Catalyst app out there for the whole world to
+see, but you don't want to break the bank. There is an answer - if you
+can get shared hosting with FastCGI and a shell, you can install your
+Catalyst app in a local directory on your shared host. First, run
- request( URI->new('http://www.host.com/my/path') );
+ perl -MCPAN -e shell
-=item An instance of C<HTTP::Request>.
+and go through the standard CPAN configuration process. Then exit out
+without installing anything. Next, open your .bashrc and add
- request( HTTP::Request->new( GET => 'http://www.host.com/my/path') );
+ export PATH=$HOME/local/bin:$HOME/local/script:$PATH
+ perlversion=`perl -v | grep 'built for' | awk '{print $4}' | sed -e 's/v//;'`
+ export PERL5LIB=$HOME/local/share/perl/$perlversion:$HOME/local/lib/perl/$perlversion:$HOME/local/lib:$PERL5LIB
-=back
+and log out, then back in again (or run C<". .bashrc"> if you
+prefer). Finally, edit C<.cpan/CPAN/MyConfig.pm> and add
-C<request> returns an instance of C<HTTP::Response> and C<get> returns the
-content (body) of the response.
+ 'make_install_arg' => qq[SITEPREFIX=$ENV{HOME}/local],
+ 'makepl_arg' => qq[INSTALLDIRS=site install_base=$ENV{HOME}/local],
-=head3 Running tests locally
+Now you can install the modules you need using CPAN as normal; they
+will be installed into your local directory, and perl will pick them
+up. Finally, change directory into the root of your virtual host and
+symlink your application's script directory in:
- mundus:~/MyApp chansen$ CATALYST_DEBUG=0 TEST_POD=1 prove --lib lib/ t/
- t/01app............ok
- t/02pod............ok
- t/03podcoverage....ok
- All tests successful.
- Files=3, Tests=4, 2 wallclock secs ( 1.60 cusr + 0.36 csys = 1.96 CPU)
-
-C<CATALYST_DEBUG=0> ensures that debugging is off; if it's enabled you
-will see debug logs between tests.
+ cd path/to/mydomain.com
+ ln -s ~/lib/MyApp/script script
-C<TEST_POD=1> enables POD checking and coverage.
+And add the following lines to your .htaccess file (assuming the server
+is setup to handle .pl as fcgi - you may need to rename the script to
+myapp_fastcgi.fcgi and/or use a SetHandler directive):
-C<prove> A command-line tool that makes it easy to run tests. You can
-find out more about it from the links below.
+ RewriteEngine On
+ RewriteCond %{REQUEST_URI} !^/?script/myapp_fastcgi.pl
+ RewriteRule ^(.*)$ script/myapp_fastcgi.pl/$1 [PT,L]
-=head3 Running tests remotely
+Now C<http://mydomain.com/> should now Just Work. Congratulations, now
+you can tell your friends about your new website (or in our case, tell
+the client it's time to pay the invoice :) )
- mundus:~/MyApp chansen$ CATALYST_SERVER=http://localhost:3000/ prove --lib lib/ t/01app.t
- t/01app....ok
- All tests successful.
- Files=1, Tests=2, 0 wallclock secs ( 0.40 cusr + 0.01 csys = 0.41 CPU)
+=head2 FastCGI Deployment
-C<CATALYST_SERVER=http://localhost:3000/> is the absolute deployment URI of
-your application. In C<CGI> or C<FastCGI> it should be the host and path
-to the script.
+FastCGI is a high-performance extension to CGI. It is suitable
+for production environments.
-=head3 C<Test::WWW::Mechanize> and Catalyst
+=head3 Pros
+
+=head4 Speed
+
+FastCGI performs equally as well as mod_perl. Don't let the 'CGI' fool you;
+your app runs as multiple persistent processes ready to receive connections
+from the web server.
-Be sure to check out C<Test::WWW::Mechanize::Catalyst>. It makes it easy to
-test HTML, forms and links. A short example of usage:
+=head4 App Server
- use Test::More tests => 6;
- use_ok( Test::WWW::Mechanize::Catalyst, 'MyApp' );
+When using external FastCGI servers, your application runs as a standalone
+application server. It may be restarted independently from the web server.
+This allows for a more robust environment and faster reload times when
+pushing new app changes. The frontend server can even be configured to
+display a friendly "down for maintenance" page while the application is
+restarting.
- my $mech = Test::WWW::Mechanize::Catalyst->new;
- $mech->get_ok("http://localhost/", 'Got index page');
- $mech->title_like( qr/^MyApp on Catalyst/, 'Got right index title' );
- ok( $mech->find_link( text_regex => qr/^Wiki/i ), 'Found link to Wiki' );
- ok( $mech->find_link( text_regex => qr/^Mailing-List/i ), 'Found link to Mailing-List' );
- ok( $mech->find_link( text_regex => qr/^IRC channel/i ), 'Found link to IRC channel' );
+=head4 Load-balancing
-=head3 Further Reading
+You can launch your application on multiple backend servers and allow the
+frontend web server to load-balance between all of them. And of course, if
+one goes down, your app continues to run fine.
-=over 4
+=head4 Multiple versions of the same app
-=item Catalyst::Test
+Each FastCGI application is a separate process, so you can run different
+versions of the same app on a single server.
-L<http://search.cpan.org/dist/Catalyst/lib/Catalyst/Test.pm>
+=head4 Can run with threaded Apache
-=item Test::WWW::Mechanize::Catalyst
+Since your app is not running inside of Apache, the faster mpm_worker module
+can be used without worrying about the thread safety of your application.
-L<http://search.cpan.org/dist/Test-WWW-Mechanize-Catalyst/lib/Test/WWW/Mechanize/Catalyst.pm>
+=head3 Cons
-=item Test::WWW::Mechanize
+=head4 More complex environment
-L<http://search.cpan.org/dist/Test-WWW-Mechanize/Mechanize.pm>
+With FastCGI, there are more things to monitor and more processes running
+than when using mod_perl.
-=item WWW::Mechanize
+=head3 Setup
-L<http://search.cpan.org/dist/WWW-Mechanize/lib/WWW/Mechanize.pm>
+=head4 1. Install Apache with mod_fastcgi
-=item LWP::UserAgent
+mod_fastcgi for Apache is a third party module, and can be found at
+L<http://www.fastcgi.com/>. It is also packaged in many distributions,
+for example, libapache2-mod-fastcgi in Debian.
-L<http://search.cpan.org/dist/libwww-perl/lib/LWP/UserAgent.pm>
+=head4 2. Configure your application
-=item HTML::Form
+ # Serve static content directly
+ DocumentRoot /var/www/MyApp/root
+ Alias /static /var/www/MyApp/root/static
-L<http://search.cpan.org/dist/libwww-perl/lib/HTML/Form.pm>
+ FastCgiServer /var/www/MyApp/script/myapp_fastcgi.pl -processes 3
+ Alias /myapp/ /var/www/MyApp/script/myapp_fastcgi.pl/
+
+ # Or, run at the root
+ Alias / /var/www/MyApp/script/myapp_fastcgi.pl/
+
+The above commands will launch 3 app processes and make the app available at
+/myapp/
-=item HTTP::Message
+=head3 Standalone server mode
-L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Message.pm>
+While not as easy as the previous method, running your app as an external
+server gives you much more flexibility.
-=item HTTP::Request
+First, launch your app as a standalone server listening on a socket.
-L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request.pm>
+ script/myapp_fastcgi.pl -l /tmp/myapp.socket -n 5 -p /tmp/myapp.pid -d
+
+You can also listen on a TCP port if your web server is not on the same
+machine.
-=item HTTP::Request::Common
+ script/myapp_fastcgi.pl -l :8080 -n 5 -p /tmp/myapp.pid -d
+
+You will probably want to write an init script to handle starting/stopping
+of the app using the pid file.
-L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request/Common.pm>
+Now, we simply configure Apache to connect to the running server.
-=item HTTP::Response
+ # 502 is a Bad Gateway error, and will occur if the backend server is down
+ # This allows us to display a friendly static page that says "down for
+ # maintenance"
+ Alias /_errors /var/www/MyApp/root/error-pages
+ ErrorDocument 502 /_errors/502.html
-L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Response.pm>
+ FastCgiExternalServer /tmp/myapp -socket /tmp/myapp.socket
+ Alias /myapp/ /tmp/myapp/
+
+ # Or, run at the root
+ Alias / /tmp/myapp/
+
+=head3 More Info
-=item HTTP::Status
+L<Catalyst::Engine::FastCGI>.
-L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Status.pm>
+=head2 Development server deployment
-=item URI
+The developemnt server is a mini web server written in perl. If you
+expect a low number of hits or you don't need mod_perl/FastCGI speed,
+you could use the development server as the application server with a
+lightweight proxy web server at the front. However, be aware that
+there are known issues, especially with Internet Explorer. Many of
+these issues can be dealt with by running the server with the -k
+(keepalive) option but be aware for more complex applications this may
+not be suitable. Consider using Catalyst::Engine::POE. This recipe
+is easily adapted for POE as well.
-L<http://search.cpan.org/dist/URI/URI.pm>
+=head3 Pros
-=item Test::More
+As this is an application server setup, the pros are the same as
+FastCGI (with the exception of speed).
+It is also:
-L<http://search.cpan.org/dist/Test-Simple/lib/Test/More.pm>
+=head4 Simple
-=item Test::Pod
+The development server is what you create your code on, so if it works here, it should work in production!
-L<http://search.cpan.org/dist/Test-Pod/Pod.pm>
+=head3 Cons
-=item Test::Pod::Coverage
+=head4 Speed
-L<http://search.cpan.org/dist/Test-Pod-Coverage/Coverage.pm>
+Not as fast as mod_perl or FastCGI. Needs to fork for each request
+that comes in - make sure static files are served by the web server to
+save forking.
-=item prove (Test::Harness)
+=head3 Setup
-L<http://search.cpan.org/dist/Test-Harness/bin/prove>
+=head4 Start up the development server
-=back
+ script/myapp_server.pl -p 8080 -k -f -pidfile=/tmp/myapp.pid -daemon
-=head2 XMLRPC
+You will probably want to write an init script to handle stop/starting
+the app using the pid file.
-Today we'll discover the wonderful world of web services.
-XMLRPC is unlike SOAP a very simple (and imo elegant) protocol,
-exchanging small XML messages like these.
+=head4 Configuring Apache
-Request:
+Make sure mod_proxy is enabled and add:
- POST /api HTTP/1.1
- TE: deflate,gzip;q=0.3
- Connection: TE, close
- Accept: text/xml
- Accept: multipart/*
- Host: 127.0.0.1:3000
- User-Agent: SOAP::Lite/Perl/0.60
- Content-Length: 192
- Content-Type: text/xml
+ # Serve static content directly
+ DocumentRoot /var/www/MyApp/root
+ Alias /static /var/www/MyApp/root/static
- <?xml version="1.0" encoding="UTF-8"?>
- <methodCall>
- <methodName>add</methodName>
- <params>
- <param><value><int>1</int></value></param>
- <param><value><int>2</int></value></param>
- </params>
- </methodCall>
+ ProxyRequests Off
+ <Proxy *>
+ Order deny,allow
+ Allow from all
+ </Proxy>
+ ProxyPass / http://localhost:8080/
+ ProxyPassReverse / http://localhost:8080/
-Response:
+You can wrap the above within a VirtualHost container if you want
+different apps served on the same host.
- Connection: close
- Date: Tue, 20 Dec 2005 07:45:55 GMT
- Content-Length: 133
- Content-Type: text/xml
- Status: 200
- X-Catalyst: 5.62
+=head2 Quick deployment: Building PAR Packages
- <?xml version="1.0" encoding="us-ascii"?>
- <methodResponse>
- <params>
- <param><value><int>3</int></value></param>
- </params>
- </methodResponse>
+You have an application running on your development box, but then you
+have to quickly move it to another one for
+demonstration/deployment/testing...
-Sweet little protocol, isn't it? :)
+PAR packages can save you from a lot of trouble here. They are usual Zip
+files that contain a blib tree; you can even include all prereqs and a
+perl interpreter by setting a few flags!
-Now follow these few steps to implement the application.
+=head3 Follow these few points to try it out!
-1. Install Catalyst (5.61 or later), Catalyst::Plugin::XMLRPC (0.06 or later) and SOAP::Lite (for XMLRPCsh.pl)
+1. Install Catalyst and PAR 0.89 (or later)
- % perl -MCPAN -e'install Catalyst'
+ % perl -MCPAN -e 'install Catalyst'
...
- % perl -MCPAN -e'install Catalyst::Plugin::XMLRPC'
+ % perl -MCPAN -e 'install PAR'
...
-2. Create a myapp
+2. Create a application
% catalyst.pl MyApp
...
% cd MyApp
-3. Add the XMLRPC plugin to MyApp.pm
-
- use Catalyst qw/-Debug Static::Simple XMLRPC/;
-
-4. Add a api controller
-
- % ./script/myapp_create.pl controller API
+Recent versions of Catalyst (5.62 and up) include
+L<Module::Install::Catalyst>, which simplifies the process greatly. From the shell in your application directory:
-5. Add a XMLRPC redispatch method and a add method with Remote attribute
-to lib/MyApp/Controller/API.pm
+ % perl Makefile.PL
+ % make catalyst_par
- sub default : Private {
- my ( $self, $c ) = @_;
- $c->xmlrpc;
- }
+Congratulations! Your package "myapp.par" is ready, the following
+steps are just optional.
- sub add : Remote {
- my ( $self, $c, $a, $b ) = @_;
- return $a + $b;
- }
+3. Test your PAR package with "parl" (no typo)
-The default action is the entry point for each XMLRPC request, it will
-redispatch every request to methods with Remote attribute in the same class.
+ % parl myapp.par
+ Usage:
+ [parl] myapp[.par] [script] [arguments]
-The add method is no traditional action, it has no private or public path.
-Only the XMLRPC dispatcher knows it exists.
+ Examples:
+ parl myapp.par myapp_server.pl -r
+ myapp myapp_cgi.pl
-6. Thats it! You have built your first web service, lets test it with
-XMLRPCsh.pl (part of SOAP::Lite)
+ Available scripts:
+ myapp_cgi.pl
+ myapp_create.pl
+ myapp_fastcgi.pl
+ myapp_server.pl
+ myapp_test.pl
- % ./script/myapp_server.pl
- ...
- % XMLRPCsh.pl http://127.0.0.1:3000/api
- Usage: method[(parameters)]
- > add( 1, 2 )
- --- XMLRPC RESULT ---
- '3'
+ % parl myapp.par myapp_server.pl
+ You can connect to your server at http://localhost:3000
-=head3 Tip Of The Day
+Yes, this nifty little starter application gets automatically included.
+You can also use "catalyst_par_script('myapp_server.pl')" to set a
+default script to execute.
-Your return data type is usually auto-detected, but you can easily
-enforce a specific one.
+6. Want to create a binary that includes the Perl interpreter?
- sub add : Remote {
- my ( $self, $c, $a, $b ) = @_;
- return RPC::XML::int->new( $a + $b );
- }
-
-=head2 Action Types
+ % pp -o myapp myapp.par
+ % ./myapp myapp_server.pl
+ You can connect to your server at http://localhost:3000
-=head3 Introduction
+=head2 Serving static content
-A Catalyst application is driven by one or more Controller modules. There are
-a number of ways that Catalyst can decide which of the methods in your
-controller modules it should call. Controller methods are also called actions,
-because they determine how your catalyst application should (re-)act to any
-given URL. When the application is started up, catalyst looks at all your
-actions, and decides which URLs they map to.
+Serving static content in Catalyst used to be somewhat tricky; the use
+of L<Catalyst::Plugin::Static::Simple> makes everything much easier.
+This plugin will automatically serve your static content during development,
+but allows you to easily switch to Apache (or other server) in a
+production environment.
-=head3 Type attributes
+=head3 Introduction to Static::Simple
-Each action is a normal method in your controller, except that it has an
-L<attribute|http://search.cpan.org/~nwclark/perl-5.8.7/lib/attributes.pm>
-attached. These can be one of several types.
+Static::Simple is a plugin that will help to serve static content for your
+application. By default, it will serve most types of files, excluding some
+standard Template Toolkit extensions, out of your B<root> file directory. All
+files are served by path, so if B<images/me.jpg> is requested, then
+B<root/images/me.jpg> is found and served.
-Assume our Controller module starts with the following package declaration:
+=head3 Usage
- package MyApp::Controller::Buckets;
+Using the plugin is as simple as setting your use line in MyApp.pm to include:
-and we are running our application on localhost, port 3000 (the test server default).
+ use Catalyst qw/Static::Simple/;
-=over 4
+and already files will be served.
-=item Path
+=head3 Configuring
-A Path attribute also takes an argument, this can be either a relative or an
-absolute path. A relative path will be relative to the controller namespace,
-an absolute path will represent an exact matching URL.
+Static content is best served from a single directory within your root
+directory. Having many different directories such as C<root/css> and
+C<root/images> requires more code to manage, because you must separately
+identify each static directory--if you decide to add a C<root/js>
+directory, you'll need to change your code to account for it. In
+contrast, keeping all static directories as subdirectories of a main
+C<root/static> directory makes things much easier to manage. Here's an
+example of a typical root directory structure:
- sub my_handles : Path('handles') { .. }
+ root/
+ root/content.tt
+ root/controller/stuff.tt
+ root/header.tt
+ root/static/
+ root/static/css/main.css
+ root/static/images/logo.jpg
+ root/static/js/code.js
-becomes
- http://localhost:3000/buckets/handles
+All static content lives under C<root/static>, with everything else being
+Template Toolkit files.
-and
+=over 4
- sub my_handles : Path('/handles') { .. }
+=item Include Path
-becomes
+You may of course want to change the default locations, and make
+Static::Simple look somewhere else, this is as easy as:
- http://localhost:3000/handles
+ MyApp->config->{static}->{include_path} = [
+ MyApp->config->{root},
+ '/path/to/my/files'
+ ];
-=item Local
+When you override include_path, it will not automatically append the
+normal root path, so you need to add it yourself if you still want
+it. These will be searched in order given, and the first matching file
+served.
-When using a Local attribute, no parameters are needed, instead, the name of
-the action is matched in the URL. The namespaces created by the name of the
-controller package is always part of the URL.
+=item Static directories
- sub my_handles : Local { .. }
+If you want to force some directories to be only static, you can set
+them using paths relative to the root dir, or regular expressions:
-becomes
+ MyApp->config->{static}->{dirs} = [
+ 'static',
+ qr/^(images|css)/,
+ ];
- http://localhost:3000/buckets/my_handles
+=item File extensions
-=item Global
+By default, the following extensions are not served (that is, they will
+be processed by Catalyst): B<tmpl, tt, tt2, html, xhtml>. This list can
+be replaced easily:
-A Global attribute is similar to a Local attribute, except that the namespace
-of the controller is ignored, and matching starts at root.
+ MyApp->config->{static}->{ignore_extensions} = [
+ qw/tmpl tt tt2 html xhtml/
+ ];
- sub my_handles : Global { .. }
+=item Ignoring directories
-becomes
+Entire directories can be ignored. If used with include_path,
+directories relative to the include_path dirs will also be ignored:
- http://localhost:3000/my_handles
+ MyApp->config->{static}->{ignore_dirs} = [ qw/tmpl css/ ];
-=item Regex
+=back
-By now you should have figured that a Regex attribute is just what it sounds
-like. This one takes a regular expression, and matches starting from
-root. These differ from the rest as they can match multiple URLs.
+=head3 More information
- sub my_handles : Regex('^handles') { .. }
+L<http://search.cpan.org/dist/Catalyst-Plugin-Static-Simple/>
-matches
+=head3 Serving manually with the Static plugin with HTTP::Daemon (myapp_server.pl)
- http://localhost:3000/handles
+In some situations you might want to control things more directly,
+using L<Catalyst::Plugin::Static>.
-and
+In your main application class (MyApp.pm), load the plugin:
- http://localhost:3000/handles_and_other_parts
+ use Catalyst qw/-Debug FormValidator Static OtherPlugin/;
-etc.
+You will also need to make sure your end method does I<not> forward
+static content to the view, perhaps like this:
-=item LocalRegex
+ sub end : Private {
+ my ( $self, $c ) = @_;
-A LocalRegex is similar to a Regex, except it only matches below the current
-controller namespace.
+ $c->forward( 'MyApp::View::TT' )
+ unless ( $c->res->body || !$c->stash->{template} );
+ }
- sub my_handles : LocalRegex(^handles') { .. }
+This code will only forward to the view if a template has been
+previously defined by a controller and if there is not already data in
+C<$c-E<gt>res-E<gt>body>.
-matches
+Next, create a controller to handle requests for the /static path. Use
+the Helper to save time. This command will create a stub controller as
+C<lib/MyApp/Controller/Static.pm>.
- http://localhost:3000/buckets/handles
+ $ script/myapp_create.pl controller Static
-and
+Edit the file and add the following methods:
- http://localhost:3000/buckets/handles_and_other_parts
+ # serve all files under /static as static files
+ sub default : Path('/static') {
+ my ( $self, $c ) = @_;
-etc.
+ # Optional, allow the browser to cache the content
+ $c->res->headers->header( 'Cache-Control' => 'max-age=86400' );
-=item Private
+ $c->serve_static; # from Catalyst::Plugin::Static
+ }
-Last but not least, there is the Private attribute, which allows you to create
-your own internal actions, which can be forwarded to, but won't be matched as
-URLs.
+ # also handle requests for /favicon.ico
+ sub favicon : Path('/favicon.ico') {
+ my ( $self, $c ) = @_;
- sub my_handles : Private { .. }
+ $c->serve_static;
+ }
-becomes nothing at all..
+You can also define a different icon for the browser to use instead of
+favicon.ico by using this in your HTML header:
-Catalyst also predefines some special Private actions, which you can override,
-these are:
+ <link rel="icon" href="/static/myapp.ico" type="image/x-icon" />
-=over 4
+=head3 Common problems with the Static plugin
-=item default
+The Static plugin makes use of the C<shared-mime-info> package to
+automatically determine MIME types. This package is notoriously
+difficult to install, especially on win32 and OS X. For OS X the easiest
+path might be to install Fink, then use C<apt-get install
+shared-mime-info>. Restart the server, and everything should be fine.
-The default action will be called, if no other matching action is found. If
-you don't have one of these in your namespace, or any sub part of your
-namespace, you'll get an error page instead. If you want to find out where it
-was the user was trying to go, you can look in the request object using
-C<< $c->req->path >>.
+Make sure you are using the latest version (>= 0.16) for best
+results. If you are having errors serving CSS files, or if they get
+served as text/plain instead of text/css, you may have an outdated
+shared-mime-info version. You may also wish to simply use the following
+code in your Static controller:
- sub default : Private { .. }
+ if ($c->req->path =~ /css$/i) {
+ $c->serve_static( "text/css" );
+ } else {
+ $c->serve_static;
+ }
-works for all unknown URLs, in this controller namespace, or every one if put
-directly into MyApp.pm.
+=head3 Serving Static Files with Apache
-=item index
+When using Apache, you can bypass Catalyst and any Static
+plugins/controllers controller by intercepting requests for the
+C<root/static> path at the server level. All that is required is to
+define a DocumentRoot and add a separate Location block for your static
+content. Here is a complete config for this application under mod_perl
+1.x:
-The index action is called when someone tries to visit the exact namespace of
-your controller. If index, default and matching Path actions are defined, then
-index will be used instead of default and Path.
+ <Perl>
+ use lib qw(/var/www/MyApp/lib);
+ </Perl>
+ PerlModule MyApp
- sub index : Private { .. }
+ <VirtualHost *>
+ ServerName myapp.example.com
+ DocumentRoot /var/www/MyApp/root
+ <Location />
+ SetHandler perl-script
+ PerlHandler MyApp
+ </Location>
+ <LocationMatch "/(static|favicon.ico)">
+ SetHandler default-handler
+ </LocationMatch>
+ </VirtualHost>
-becomes
+And here's a simpler example that'll get you started:
- http://localhost:3000/buckets
+ Alias /static/ "/my/static/files/"
+ <Location "/static">
+ SetHandler none
+ </Location>
-=item begin
+=head2 Caching
-The begin action is called at the beginning of every request involving this
-namespace directly, before other matching actions are called. It can be used
-to set up variables/data for this particular part of your app. A single begin
-action is called, its always the one most relevant to the current namespace.
+Catalyst makes it easy to employ several different types of caching to
+speed up your applications.
- sub begin : Private { .. }
+=head3 Cache Plugins
-is called once when
+There are three wrapper plugins around common CPAN cache modules:
+Cache::FastMmap, Cache::FileCache, and Cache::Memcached. These can be
+used to cache the result of slow operations.
- http://localhost:3000/bucket/(anything)?
+This very page you're viewing makes use of the FileCache plugin to cache the
+rendered XHTML version of the source POD document. This is an ideal
+application for a cache because the source document changes infrequently but
+may be viewed many times.
-is visited.
+ use Catalyst qw/Cache::FileCache/;
+
+ ...
+
+ use File::stat;
+ sub render_pod : Local {
+ my ( self, $c ) = @_;
+
+ # the cache is keyed on the filename and the modification time
+ # to check for updates to the file.
+ my $file = $c->path_to( 'root', '2005', '11.pod' );
+ my $mtime = ( stat $file )->mtime;
+
+ my $cached_pod = $c->cache->get("$file $mtime");
+ if ( !$cached_pod ) {
+ $cached_pod = do_slow_pod_rendering();
+ # cache the result for 12 hours
+ $c->cache->set( "$file $mtime", $cached_pod, '12h' );
+ }
+ $c->stash->{pod} = $cached_pod;
+ }
+
+We could actually cache the result forever, but using a value such as 12 hours
+allows old entries to be automatically expired when they are no longer needed.
-=item end
+=head3 Page Caching
-Like begin, this action is always called for the namespace it is in, after
-every other action has finished. It is commonly used to forward processing to
-the View component. A single end action is called, its always the one most
-relevant to the current namespace.
+Another method of caching is to cache the entire HTML page. While this is
+traditionally handled by a front-end proxy server like Squid, the Catalyst
+PageCache plugin makes it trivial to cache the entire output from
+frequently-used or slow actions.
+Many sites have a busy content-filled front page that might look something
+like this. It probably takes a while to process, and will do the exact same
+thing for every single user who views the page.
- sub end : Private { .. }
+ sub front_page : Path('/') {
+ my ( $self, $c ) = @_;
+
+ $c->forward( 'get_news_articles' );
+ $c->forward( 'build_lots_of_boxes' );
+ $c->forward( 'more_slow_stuff' );
+
+ $c->stash->{template} = 'index.tt';
+ }
-is called once after any actions when
+We can add the PageCache plugin to speed things up.
- http://localhost:3000/bucket/(anything)?
+ use Catalyst qw/Cache::FileCache PageCache/;
+
+ sub front_page : Path ('/') {
+ my ( $self, $c ) = @_;
+
+ $c->cache_page( 300 );
+
+ # same processing as above
+ }
+
+Now the entire output of the front page, from <html> to </html>, will be
+cached for 5 minutes. After 5 minutes, the next request will rebuild the
+page and it will be re-cached.
-is visited.
+Note that the page cache is keyed on the page URI plus all parameters, so
+requests for / and /?foo=bar will result in different cache items. Also,
+only GET requests will be cached by the plugin.
-=item auto
+You can even get that front-end Squid proxy to help out by enabling HTTP
+headers for the cached page.
-Lastly, the auto action is magic in that B<every> auto action in
-the chain of paths up to and including the ending namespace, will be
-called. (In contrast, only one of the begin/end/default actions will be
-called, the relevant one).
+ MyApp->config->{page_cache}->{set_http_headers} = 1;
+
+This would now set the following headers so proxies and browsers may cache
+the content themselves.
- package MyApp.pm;
- sub auto : Private { .. }
+ Cache-Control: max-age=($expire_time - time)
+ Expires: $expire_time
+ Last-Modified: $cache_created_time
+
+=head3 Template Caching
-and
+Template Toolkit provides support for caching compiled versions of your
+templates. To enable this in Catalyst, use the following configuration.
+TT will cache compiled templates keyed on the file mtime, so changes will
+still be automatically detected.
- sub auto : Private { .. }
+ package MyApp::View::TT;
+
+ use strict;
+ use warnings;
+ use base 'Catalyst::View::TT';
+
+ __PACKAGE__->config(
+ COMPILE_DIR => '/tmp/template_cache',
+ );
+
+ 1;
+
+=head3 More Info
-will both be called when visiting
+See the documentation for each cache plugin for more details and other
+available configuration options.
- http://localhost:3000/bucket/(anything)?
+L<Catalyst::Plugin::Cache::FastMmap>
+L<Catalyst::Plugin::Cache::FileCache>
+L<Catalyst::Plugin::Cache::Memcached>
+L<Catalyst::Plugin::PageCache>
+L<http://search.cpan.org/dist/Template-Toolkit/lib/Template/Manual/Config.pod#Caching_and_Compiling_Options>
-=back
+=head1 Testing
-=back
+Testing is an integral part of the web application development
+process. Tests make multi developer teams easier to coordinate, and
+they help ensure that there are no nasty surprises after upgrades or
+alterations.
-=head3 A word of warning
+=head2 Testing
-Due to possible namespace conflicts with Plugins, it is advised to only put the
-pre-defined Private actions in your main MyApp.pm file, all others should go
-in a Controller module.
+Catalyst provides a convenient way of testing your application during
+development and before deployment in a real environment.
-=head3 More Information
+C<Catalyst::Test> makes it possible to run the same tests both locally
+(without an external daemon) and against a remote server via HTTP.
-L<http://search.cpan.org/author/SRI/Catalyst-5.61/lib/Catalyst/Manual/Intro.pod>
+=head3 Tests
-L<http://dev.catalyst.perl.org/wiki/FlowChart>
+Let's examine a skeleton application's C<t/> directory:
-=head2 Static::Simple
+ mundus:~/MyApp chansen$ ls -l t/
+ total 24
+ -rw-r--r-- 1 chansen chansen 95 18 Dec 20:50 01app.t
+ -rw-r--r-- 1 chansen chansen 190 18 Dec 20:50 02pod.t
+ -rw-r--r-- 1 chansen chansen 213 18 Dec 20:50 03podcoverage.t
-=head3 Introduction
+=over 4
-Static::Simple is a plugin that will help to serve static content for your
-application. By default, it will serve most types of files, excluding some
-standard Template Toolkit extensions, out of your B<root> file directory. All
-files are served by path, so if B<images/me.jpg> is requested, then
-B<root/images/me.jpg> is found and served.
+=item C<01app.t>
-=head3 Usage
+Verifies that the application loads, compiles, and returns a successful
+response.
-Using the plugin is as simple as setting your use line in MyApp.pm to:
+=item C<02pod.t>
- use Catalyst qw/Static::Simple/;
+Verifies that all POD is free from errors. Only executed if the C<TEST_POD>
+environment variable is true.
-and already files will be served.
+=item C<03podcoverage.t>
-=head3 Configuring
+Verifies that all methods/functions have POD coverage. Only executed if the
+C<TEST_POD> environment variable is true.
-=over 4
+=back
-=item Include Path
+=head3 Creating tests
-You may of course want to change the default locations, and make
-Static::Simple look somewhere else, this is as easy as:
+ mundus:~/MyApp chansen$ cat t/01app.t | perl -ne 'printf( "%2d %s", $., $_ )'
+ 1 use Test::More tests => 2;
+ 2 use_ok( Catalyst::Test, 'MyApp' );
+ 3
+ 4 ok( request('/')->is_success );
- MyApp->config->{static}->{include_path} = [
- MyApp->config->{root},
- '/path/to/my/files'
- ];
+The first line declares how many tests we are going to run, in this case
+two. The second line tests and loads our application in test mode. The
+fourth line verifies that our application returns a successful response.
-When you override include_path, it will not automatically append the normal
-root path, so you need to add it yourself if you still want it. These will be
-searched in order given, and the first matching file served.
+C<Catalyst::Test> exports two functions, C<request> and C<get>. Each can
+take three different arguments:
-=item Static directories
+=over 4
-If you want to force some directories to be only static, you can set them
-using paths relative to the root dir, or regular expressions:
+=item A string which is a relative or absolute URI.
- MyApp->config->{static}->{dirs} = [
- 'static',
- qr/^(images|css)/,
- ];
+ request('/my/path');
+ request('http://www.host.com/my/path');
-=item File extensions
+=item An instance of C<URI>.
-By default, the following extensions are not served: B<tmpl, tt, tt2, html,
-xhtml>. This list can be replaced easily:
+ request( URI->new('http://www.host.com/my/path') );
- MyApp->config->{static}->{ignore_extensions} = [
- qw/tmpl tt tt2 html xhtml/
- ];
+=item An instance of C<HTTP::Request>.
-=item Ignoring directories
+ request( HTTP::Request->new( GET => 'http://www.host.com/my/path') );
-Entire directories can be ignored. If used with include_path, directories
-relative to the include_path dirs will also be ignored:
+=back
- MyApp->config->{static}->{ignore_dirs} = [ qw/tmpl css/ ];
+C<request> returns an instance of C<HTTP::Response> and C<get> returns the
+content (body) of the response.
-=back
+=head3 Running tests locally
-=head3 More information
+ mundus:~/MyApp chansen$ CATALYST_DEBUG=0 TEST_POD=1 prove --lib lib/ t/
+ t/01app............ok
+ t/02pod............ok
+ t/03podcoverage....ok
+ All tests successful.
+ Files=3, Tests=4, 2 wallclock secs ( 1.60 cusr + 0.36 csys = 1.96 CPU)
+
+C<CATALYST_DEBUG=0> ensures that debugging is off; if it's enabled you
+will see debug logs between tests.
-L<http://search.cpan.org/dist/Catalyst-Plugin-Static-Simple/>
+C<TEST_POD=1> enables POD checking and coverage.
-=head2 Authorization
+C<prove> A command-line tool that makes it easy to run tests. You can
+find out more about it from the links below.
-=head3 Introduction
+=head3 Running tests remotely
-Authorization is the step that comes after authentication. Authentication
-establishes that the user agent is really representing the user we think it's
-representing, and then authorization determines what this user is allowed to
-do.
+ mundus:~/MyApp chansen$ CATALYST_SERVER=http://localhost:3000/ prove --lib lib/ t/01app.t
+ t/01app....ok
+ All tests successful.
+ Files=1, Tests=2, 0 wallclock secs ( 0.40 cusr + 0.01 csys = 0.41 CPU)
-=head3 Role Based Access Control
+C<CATALYST_SERVER=http://localhost:3000/> is the absolute deployment URI of
+your application. In C<CGI> or C<FastCGI> it should be the host and path
+to the script.
-Under role based access control each user is allowed to perform any number of
-roles. For example, at a zoo no one but specially trained personnel can enter
-the moose cage (Mynd you, møøse bites kan be pretty nasti!). For example:
+=head3 C<Test::WWW::Mechanize> and Catalyst
- package Zoo::Controller::MooseCage;
+Be sure to check out C<Test::WWW::Mechanize::Catalyst>. It makes it easy to
+test HTML, forms and links. A short example of usage:
- sub feed_moose : Local {
- my ( $self, $c ) = @_;
+ use Test::More tests => 6;
+ use_ok( Test::WWW::Mechanize::Catalyst, 'MyApp' );
- $c->model( "Moose" )->eat( $c->req->param("food") );
- }
+ my $mech = Test::WWW::Mechanize::Catalyst->new;
+ $mech->get_ok("http://localhost/", 'Got index page');
+ $mech->title_like( qr/^MyApp on Catalyst/, 'Got right index title' );
+ ok( $mech->find_link( text_regex => qr/^Wiki/i ), 'Found link to Wiki' );
+ ok( $mech->find_link( text_regex => qr/^Mailing-List/i ), 'Found link to Mailing-List' );
+ ok( $mech->find_link( text_regex => qr/^IRC channel/i ), 'Found link to IRC channel' );
-With this action, anyone can just come into the moose cage and feed the moose,
-which is a very dangerous thing. We need to restrict this action, so that only
-a qualified moose feeder can perform that action.
+=head3 Further Reading
-The Authorization::Roles plugin let's us perform role based access control
-checks. Let's load it:
+=over 4
- use Catalyst qw/
- Authentication # yadda yadda
- Authorization::Roles
- /;
+=item Catalyst::Test
-And now our action should look like this:
+L<http://search.cpan.org/dist/Catalyst/lib/Catalyst/Test.pm>
- sub feed_moose : Local {
- my ( $self, $c ) = @_;
+=item Test::WWW::Mechanize::Catalyst
- if ( $c->check_roles( "moose_feeder" ) ) {
- $c->model( "Moose" )->eat( $c->req->param("food") );
- } else {
- $c->stash->{error} = "unauthorized";
- }
- }
+L<http://search.cpan.org/dist/Test-WWW-Mechanize-Catalyst/lib/Test/WWW/Mechanize/Catalyst.pm>
-This checks C<< $c->user >>, and only if the user has B<all> the roles in the
-list, a true value is returned.
+=item Test::WWW::Mechanize
-C<check_roles> has a sister method, C<assert_roles>, which throws an exception
-if any roles are missing.
+L<http://search.cpan.org/dist/Test-WWW-Mechanize/Mechanize.pm>
-Some roles that might actually make sense in, say, a forum application:
+=item WWW::Mechanize
-=over 4
+L<http://search.cpan.org/dist/WWW-Mechanize/lib/WWW/Mechanize.pm>
-=item *
+=item LWP::UserAgent
-administrator
+L<http://search.cpan.org/dist/libwww-perl/lib/LWP/UserAgent.pm>
-=item *
+=item HTML::Form
-moderator
+L<http://search.cpan.org/dist/libwww-perl/lib/HTML/Form.pm>
-=back
+=item HTTP::Message
-each with a distinct task (system administration versus content administration).
+L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Message.pm>
-=head3 Access Control Lists
+=item HTTP::Request
-Checking for roles all the time can be tedious and error prone.
+L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request.pm>
-The Authorization::ACL plugin let's us declare where we'd like checks to be
-done automatically for us.
+=item HTTP::Request::Common
-For example, we may want to completely block out anyone who isn't a
-C<moose_feeder> from the entire C<MooseCage> controller:
+L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request/Common.pm>
- Zoo->deny_access_unless( "/moose_cage", [qw/moose_feeder/] );
+=item HTTP::Response
-The role list behaves in the same way as C<check_roles>. However, the ACL
-plugin isn't limited to just interacting with the Roles plugin. We can use a
-code reference instead. For example, to allow either moose trainers or moose
-feeders into the moose cage, we can create a more complex check:
+L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Response.pm>
- Zoo->deny_access_unless( "/moose_cage", sub {
- my $c = shift;
- $c->check_roles( "moose_trainer" ) || $c->check_roles( "moose_feeder" );
- });
+=item HTTP::Status
-The more specific a role, the earlier it will be checked. Let's say moose
-feeders are now restricted to only the C<feed_moose> action, while moose
-trainers get access everywhere:
+L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Status.pm>
- Zoo->deny_access_unless( "/moose_cage", [qw/moose_trainer/] );
- Zoo->allow_access_if( "/moose_cage/feed_moose", [qw/moose_feeder/]);
+=item URI
-When the C<feed_moose> action is accessed the second check will be made. If the
-user is a C<moose_feeder>, then access will be immediately granted. Otherwise,
-the next rule in line will be tested - the one checking for a C<moose_trainer>.
-If this rule is not satisfied, access will be immediately denied.
+L<http://search.cpan.org/dist/URI/URI.pm>
-Rules applied to the same path will be checked in the order they were added.
+=item Test::More
-Lastly, handling access denial events is done by creating an C<access_denied>
-private action:
+L<http://search.cpan.org/dist/Test-Simple/lib/Test/More.pm>
- sub access_denied : Private {
- my ( $self, $c, $action ) = @_;
+=item Test::Pod
-
- }
+L<http://search.cpan.org/dist/Test-Pod/Pod.pm>
-This action works much like auto, in that it is inherited across namespaces
-(not like object oriented code). This means that the C<access_denied> action
-which is B<nearest> to the action which was blocked will be triggered.
+=item Test::Pod::Coverage
-If this action does not exist, an error will be thrown, which you can clean up
-in your C<end> private action instead.
+L<http://search.cpan.org/dist/Test-Pod-Coverage/Coverage.pm>
-Also, it's important to note that if you restrict access to "/" then C<end>,
-C<default>, etc will also be restricted.
+=item prove (Test::Harness)
- MyApp->acl_allow_root_internals;
+L<http://search.cpan.org/dist/Test-Harness/bin/prove>
-will create rules that permit access to C<end>, C<begin>, and C<auto> in the
-root of your app (but not in any other controller).
+=back
=head3 More Information
=head1 AUTHORS
-Sebastian Riedel, C<sri@oook.de>
-Danijel Milicevic, C<me@danijel.de>
-Viljo Marrandi, C<vilts@yahoo.com>
-Marcus Ramberg, C<mramberg@cpan.org>
-Jesse Sheidlower, C<jester@panix.com>
-Andy Grundman, C<andy@hybridized.org>
-Chisel Wright, C<pause@herlpacker.co.uk>
-Will Hawes, C<info@whawes.co.uk>
-Gavin Henry, C<ghenry@perl.me.uk>
+Sebastian Riedel C<sri@oook.de>
+
+Danijel Milicevic C<me@danijel.de>
+Viljo Marrandi C<vilts@yahoo.com>
+
+Marcus Ramberg C<mramberg@cpan.org>
+
+Jesse Sheidlower C<jester@panix.com>
+
+Andy Grundman C<andy@hybridized.org>
+
+Chisel Wright C<pause@herlpacker.co.uk>
+
+Will Hawes C<info@whawes.co.uk>
+
+Gavin Henry C<ghenry@perl.me.uk>
+
+Kieren Diment C<kd@totaldatasolution.com>
=head1 COPYRIGHT
-This program is free software, you can redistribute it and/or modify it
+This document is free, you can redistribute it and/or modify it
under the same terms as Perl itself.
+
projects / catagits/Catalyst-Runtime.git / blobdiff