-
-=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, $c ) = @_;
- die "forced debug";
- }
+=head2 Delivering a Custom Error Page
+
+By default, Catalyst will display its own error page whenever it
+encounters an error in your application. When running under C<-Debug>
+mode, the error page is a useful screen including the error message and
+L<Data::Dump> output of the relevant parts of the C<$c> context object.
+When not in C<-Debug>, users see a simple "Please come back later" screen.
+
+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>).
+
+ 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);
+ }
+
+ return 1 if $c->response->status =~ /^3\d\d$/;
+ return 1 if $c->response->body;
-If you're tired of removing and adding this all the time, you can add a
-condition in the C<end> action. For example:
+ unless ( $c->response->content_type ) {
+ $c->response->content_type('text/html; charset=utf-8');
+ }
- sub end : Private {
- my ( $self, $c ) = @_;
- die "forced debug" if $c->req->params->{dump_info};
- }
+ $c->forward('MyApp::View::TT');
+ }
-Then just add to your query string C<&dump_info=1> (or if there's no
-query string for the request, add C<?dump_info=1> to the end of the URL)
-to force debug output. This feature is included in
-L<Catlyst::Plugin::DefaultEnd>.
+You can manually set errors in your code to trigger this page by calling
+ $c->error( 'You broke me!' );
=head2 Disable statistics
your C<use Catalyst> statement. However, you can also enable it using
environment variable, so you can (for example) get debug info without
modifying your application scripts. Just set C<CATALYST_DEBUG> or
-C<E<LT>MYAPPE<GT>_DEBUG> to a true value.
+C<E<lt>MYAPPE<gt>_DEBUG> to a true value.
-=head2 File uploads
+=head2 Sessions
-=head3 Single file upload with Catalyst
+When you have your users identified, you will want to somehow remember that
+fact, to save them from having to identify themselves for every single
+page. One way to do this is to send the username and password parameters in
+every single page, but that's ugly, and won't work for static pages.
-To implement uploads in Catalyst, you need to have a HTML form similar to
-this:
+Sessions are a method of saving data related to some transaction, and giving
+the whole collection a single ID. This ID is then given to the user to return
+to us on every page they visit while logged in. The usual way to do this is
+using a browser cookie.
- <form action="/upload" method="post" enctype="multipart/form-data">
- <input type="hidden" name="form_submit" value="yes">
- <input type="file" name="my_file">
- <input type="submit" value="Send">
- </form>
+Catalyst uses two types of plugins to represent sessions:
-It's very important not to forget C<enctype="multipart/form-data"> in
-the form.
+=head3 State
-Catalyst Controller module 'upload' action:
+A State module is used to keep track of the state of the session between the
+users browser, and your application.
- sub upload : Global {
- my ($self, $c) = @_;
+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.
- if ( $c->request->parameters->{form_submit} eq 'yes' ) {
+=head3 Store
- if ( my $upload = $c->request->upload('my_file') ) {
+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).
- my $filename = $upload->filename;
- my $target = "/tmp/upload/$filename";
+=head3 Authentication magic
- unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
- die( "Failed to copy '$filename' to '$target': $!" );
- }
- }
- }
+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.
- $c->stash->{template} = 'file_upload.html';
- }
+=head3 Using a session
-=head3 Multiple file upload with Catalyst
+Once the session modules are loaded, the session is available as C<<
+$c->session >>, and can be writen to and read from as a simple hash reference.
-Code for uploading multiple files from one form needs a few changes:
+=head3 EXAMPLE
-The form should have this basic structure:
+ use Catalyst qw/
+ Session
+ Session::Store::FastMmap
+ Session::State::Cookie
+ /;
- <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>
-And in the controller:
+ ## Write data into the session
- sub upload : Local {
- my ($self, $c) = @_;
+ sub add_item : Local {
+ my ( $self, $c ) = @_;
- if ( $c->request->parameters->{form_submit} eq 'yes' ) {
+ my $item_id = $c->req->param("item");
- for my $field ( $c->req->upload ) {
+ push @{ $c->session->{items} }, $item_id;
- my $upload = $c->req->upload($field);
- my $filename = $upload->filename;
- my $target = "/tmp/upload/$filename";
+ }
- unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
- die( "Failed to copy '$filename' to '$target': $!" );
- }
- }
- }
+ ## A page later we retrieve the data from the session:
- $c->stash->{template} = 'file_upload.html';
- }
+ sub get_items : Local {
+ my ( $self, $c ) = @_;
-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.
+ $c->stash->{items_to_display} = $c->session->{items};
-Notice: C<die>ing might not be what you want to do, when an error
-occurs, but it works as an example. A better idea would be to store
-error C<$!> 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
+
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session>
+
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-Cookie>
+
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-URI>
+
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-FastMmap>
+
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-File>
+
+L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-DBI>
+
+=head2 Configure your application
+
+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.
+
+=head3 Using YAML
+
+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.
+
+In your application class (e.g. C<lib/MyApp.pm>):
+
+ use YAML;
+ # application setup
+ __PACKAGE__->config( YAML::LoadFile(__PACKAGE__->config->{'home'} . '/myapp.yml') );
+ __PACKAGE__->setup;
+
+Now create C<myapp.yml> in your application home:
+
+ --- #YAML:1.0
+ # DO NOT USE TABS FOR INDENTATION OR label/value SEPARATION!!!
+ name: MyApp
+
+ # session; perldoc Catalyst::Plugin::Session::FastMmap
+ session:
+ expires: '3600'
+ rewrite: '0'
+ storage: '/tmp/myapp.session'
+
+ # emails; perldoc Catalyst::Plugin::Email
+ # this passes options as an array :(
+ email:
+ - SMTP
+ - localhost
+
+This is equivalent to:
+
+ # 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/];
+
+See also L<YAML>.
+
+=head1 Skipping your VCS's directories
+
+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.
+
+You can make catalyst skip these directories using the Catalyst config:
+
+ # Configure the application
+ __PACKAGE__->config(
+ name => 'MyApp',
+ setup_components => { except => qr/SCCS/ },
+ );
+
+See the Module::Pluggable manual page for more information on B<except>
+and other options.
+
+=head1 Users and Access Control
+
+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.
=head2 Authentication (logging in)
}
-=head2 Serving static content
-
-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.
+=head2 Role-based Authorization
-=head3 Introduction to Static::Simple
+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.
-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.
+The C<login> and C<logout> methods and view template are exactly the same as
+in the previous example.
-=head3 Usage
+The L<Catalyst::Plugin::Authorization::Roles> plugin is required when
+implementing roles:
-Using the plugin is as simple as setting your use line in MyApp.pm to include:
+ use Catalyst qw/
+ Authentication
+ Authentication::Credential::Password
+ Authentication::Store::Htpasswd
+ Authorization::Roles
+ /;
- use Catalyst qw/Static::Simple/;
+Roles are implemented automatically when using
+L<Catalyst::Authentication::Store::Htpasswd>:
-and already files will be served.
+ # no additional role configuration required
+ __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
-=head3 Configuring
+Or can be set up manually when using L<Catalyst::Authentication::Store::DBIC>:
-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:
-
- 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
-
-
-All static content lives under C<root/static>, with everything else being
-Template Toolkit files.
+ # 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',
-=over 4
+ # DBIx::Class only (omit if using Class::DBI)
+ 'role_rel' => 'user_role',
-=item Include Path
+ # Class::DBI only, (omit if using DBIx::Class)
+ 'user_role_class' => 'My::Model::CDBI::UserRole'
+ 'user_role_role_field' => 'role',
+ };
-You may of course want to change the default locations, and make
-Static::Simple look somewhere else, this is as easy as:
+To restrict access to any action, you can use the C<check_user_roles> method:
- MyApp->config->{static}->{include_path} = [
- MyApp->config->{root},
- '/path/to/my/files'
- ];
+ sub restricted : Local {
+ my ( $self, $c ) = @_;
-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->detach("unauthorized")
+ unless $c->check_user_roles( "admin" );
-=item Static directories
+ # do something restricted here
+ }
-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:
+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:
- MyApp->config->{static}->{dirs} = [
- 'static',
- qr/^(images|css)/,
- ];
+ sub also_restricted : Global {
+ my ( $self, $c ) = @_;
+ $c->assert_user_roles( qw/ user admin / );
+ }
+
+=head2 Authentication/Authorization
-=item File extensions
+This is done in several steps:
-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:
+=over 4
- MyApp->config->{static}->{ignore_extensions} = [
- qw/tmpl tt tt2 html xhtml/
- ];
+=item Verification
-=item Ignoring directories
+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>.
-Entire directories can be ignored. If used with include_path,
-directories relative to the include_path dirs will also be ignored:
+=item Authorization
- MyApp->config->{static}->{ignore_dirs} = [ qw/tmpl css/ ];
+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.
=back
-=head3 More information
-
-L<http://search.cpan.org/dist/Catalyst-Plugin-Static-Simple/>
-
-=head3 Serving manually with the Static plugin with HTTP::Daemon (myapp_server.pl)
-
-In some situations you might want to control things more directly,
-using L<Catalyst::Plugin::Static>.
-
-In your main application class (MyApp.pm), load the plugin:
-
- use Catalyst qw/-Debug FormValidator Static OtherPlugin/;
-
-You will also need to make sure your end method does I<not> forward
-static content to the view, perhaps like this:
-
- sub end : Private {
- my ( $self, $c ) = @_;
+=head3 Modules
- $c->forward( 'MyApp::View::TT' )
- unless ( $c->res->body || !$c->stash->{template} );
- }
+The Catalyst Authentication system is made up of many interacting modules, to
+give you the most flexibility possible.
-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>.
+=head4 Credential verifiers
-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>.
+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.
- $ script/myapp_create.pl controller Static
+Examples:
-Edit the file and add the following methods:
+ Password - Simple username/password checking.
+ HTTPD - Checks using basic HTTP auth.
+ TypeKey - Check using the typekey system.
- # serve all files under /static as static files
- sub default : Path('/static') {
- my ( $self, $c ) = @_;
+=head3 Storage backends
- # Optional, allow the browser to cache the content
- $c->res->headers->header( 'Cache-Control' => 'max-age=86400' );
+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.
- $c->serve_static; # from Catalyst::Plugin::Static
- }
+Examples:
- # also handle requests for /favicon.ico
- sub favicon : Path('/favicon.ico') {
- my ( $self, $c ) = @_;
+ DBIC - Storage using a database.
+ Minimal - Storage using a simple hash (for testing).
- $c->serve_static;
- }
+=head3 User objects
-You can also define a different icon for the browser to use instead of
-favicon.ico by using this in your HTML header:
+A User object is created by either the storage backend or the credential
+verifier, and filled with the retrieved user information.
- <link rel="icon" href="/static/myapp.ico" type="image/x-icon" />
+Examples:
-=head3 Common problems with the Static plugin
+ Hash - A simple hash of keys and values.
-The Static plugin makes use of the C<shared-mime-info> package to
-automatically determine MIME types. This package is notoriously
-difficult to install, especially on win32 and OS X. For OS X the easiest
-path might be to install Fink, then use C<apt-get install
-shared-mime-info>. Restart the server, and everything should be fine.
+=head3 ACL authorization
-Make sure you are using the latest version (>= 0.16) for best
-results. If you are having errors serving CSS files, or if they get
-served as text/plain instead of text/css, you may have an outdated
-shared-mime-info version. You may also wish to simply use the following
-code in your Static controller:
+ACL stands for Access Control List. The ACL plugin allows you to regulate
+access on a path by path basis, by listing which users, or roles, have access
+to which paths.
- if ($c->req->path =~ /css$/i) {
- $c->serve_static( "text/css" );
- } else {
- $c->serve_static;
- }
+=head3 Roles authorization
-=head3 Serving Static Files with Apache
+Authorization by roles is for assigning users to groups, which can then be
+assigned to ACLs, or just checked when needed.
-When using Apache, you can bypass Catalyst and any Static
-plugins/controllers controller by intercepting requests for the
-C<root/static> path at the server level. All that is required is to
-define a DocumentRoot and add a separate Location block for your static
-content. Here is a complete config for this application under mod_perl
-1.x:
+=head3 Logging in
- <Perl>
- use lib qw(/var/www/MyApp/lib);
- </Perl>
- PerlModule MyApp
+When you have chosen your modules, all you need to do is call the C<<
+$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.
- <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>
+=head3 Checking roles
-And here's a simpler example that'll get you started:
+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.
- Alias /static/ "/my/static/files/"
- <Location "/static">
- SetHandler none
- </Location>
+=head3 EXAMPLE
-=head2 Forwarding with arguments
+ use Catalyst qw/Authentication
+ Authentication::Credential::Password
+ Authentication::Store::Htpasswd
+ Authorization::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:
+ __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
- # version 5.30 and later:
- $c->forward('/wherever', [qw/arg1 arg2 arg3/]);
+ sub login : Local {
+ my ($self, $c) = @_;
- # pre-5.30
- $c->req->args([qw/arg1 arg2 arg3/]);
- $c->forward('/wherever');
+ 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
+ }
+ }
-(See the L<Catalyst::Manual::Intro> Flow_Control section for more
-information on passing arguments via C<forward>.)
+ sub restricted : Local {
+ my ( $self, $c ) = @_;
-=head2 Configure your application
+ $c->detach("unauthorized")
+ unless $c->check_user_roles( "admin" );
-You configure your application with the C<config> method in your
-application class. This can be hard-coded, or brought in from a
-separate configuration file.
+ # do something restricted here
+ }
-=head3 Using YAML
+=head3 Using authentication in a testing environment
-YAML is a method for creating flexible and readable configuration
-files. It's a great way to keep your Catalyst application configuration
-in one easy-to-understand location.
+Ideally, to write tests for authentication/authorization code one would first
+set up a test database with known data, then use
+L<Test::WWW::Mechanize::Catalyst> to simulate a user logging in. Unfortunately
+the former can be rather awkward, which is why it's a good thing that the
+authentication framework is so flexible.
-In your application class (e.g. C<lib/MyApp.pm>):
+Instead of using a test database, one can simply change the authentication
+store to something a bit easier to deal with in a testing
+environment. Additionally, this has the advantage of not modifying one's
+database, which can be problematic if one forgets to use the testing instead of
+production database.
- use YAML;
- # application setup
- __PACKAGE__->config( YAML::LoadFile(__PACKAGE__->config->{'home'} . '/myapp.yml') );
- __PACKAGE__->setup;
+e.g.,
-Now create C<myapp.yml> in your application home:
+ use Catalyst::Plugin::Authentication::Store::Minimal::Backend;
- --- #YAML:1.0
- # DO NOT USE TABS FOR INDENTATION OR label/value SEPARATION!!!
- name: MyApp
+ # Sets up the user `test_user' with password `test_pass'
+ MyApp->default_auth_store(
+ Catalyst::Plugin::Authentication::Store::Minimal::Backend->new({
+ test_user => { password => 'test_pass' },
+ })
+ );
- # session; perldoc Catalyst::Plugin::Session::FastMmap
- session:
- expires: '3600'
- rewrite: '0'
- storage: '/tmp/myapp.session'
+Now, your test code can call C<$c->login('test_user', 'test_pass')> and
+successfully login, without messing with the database at all.
- # emails; perldoc Catalyst::Plugin::Email
- # this passes options as an array :(
- email:
- - SMTP
- - localhost
+=head3 More information
-This is equivalent to:
+L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authentication> has a longer explanation.
- # 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/];
+=head2 Authorization
-See also L<YAML>.
+=head3 Introduction
-=head2 Using existing DBIC (etc.) classes with Catalyst
+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.
-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:
+=head3 Role Based Access Control
- 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;
+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:
-and that's it! Now C<Some::DBIC::Schema> is part of your
-Cat app as C<MyApp::Model::DB>.
+ package Zoo::Controller::MooseCage;
-=head2 Delivering a Custom Error Page
+ sub feed_moose : Local {
+ my ( $self, $c ) = @_;
-By default, Catalyst will display its own error page whenever it
-encounters an error in your application. When running under C<-Debug>
-mode, the error page is a useful screen including the error message and
-L<Data::Dump> output of the relevant parts of the C<$c> context object.
-When not in C<-Debug>, users see a simple "Please come back later" screen.
+ $c->model( "Moose" )->eat( $c->req->param("food") );
+ }
-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>).
+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 end : Private {
- my ( $self, $c ) = @_;
+The Authorization::Roles plugin let's us perform role based access control
+checks. Let's load it:
- if ( scalar @{ $c->error } ) {
- $c->stash->{errors} = $c->error;
- $c->stash->{template} = 'errors.tt';
- $c->forward('MyApp::View::TT');
- $c->error(0);
- }
+ use Catalyst qw/
+ Authentication # yadda yadda
+ Authorization::Roles
+ /;
- return 1 if $c->response->status =~ /^3\d\d$/;
- return 1 if $c->response->body;
+And now our action should look like this:
- unless ( $c->response->content_type ) {
- $c->response->content_type('text/html; charset=utf-8');
- }
+ sub feed_moose : Local {
+ my ( $self, $c ) = @_;
- $c->forward('MyApp::View::TT');
+ if ( $c->check_roles( "moose_feeder" ) ) {
+ $c->model( "Moose" )->eat( $c->req->param("food") );
+ } else {
+ $c->stash->{error} = "unauthorized";
+ }
}
-You can manually set errors in your code to trigger this page by calling
+This checks C<< $c->user >>, and only if the user has B<all> the roles in the
+list, a true value is returned.
- $c->error( 'You broke me!' );
+C<check_roles> has a sister method, C<assert_roles>, which throws an exception
+if any roles are missing.
-=head2 Role-based Authorization
+Some roles that might actually make sense in, say, a forum application:
-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.
+=over 4
-The C<login> and C<logout> methods and view template are exactly the same as
-in the previous example.
+=item *
-The L<Catalyst::Plugin::Authorization::Roles> plugin is required when
-implementing roles:
+administrator
- use Catalyst qw/
- Authentication
- Authentication::Credential::Password
- Authentication::Store::Htpasswd
- Authorization::Roles
- /;
+=item *
-Roles are implemented automatically when using
-L<Catalyst::Authentication::Store::Htpasswd>:
+moderator
- # no additional role configuration required
- __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
+=back
-Or can be set up manually when using L<Catalyst::Authentication::Store::DBIC>:
+each with a distinct task (system administration versus content administration).
- # 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',
+=head3 Access Control Lists
- # DBIx::Class only (omit if using Class::DBI)
- 'role_rel' => 'user_role',
+Checking for roles all the time can be tedious and error prone.
- # Class::DBI only, (omit if using DBIx::Class)
- 'user_role_class' => 'My::Model::CDBI::UserRole'
- 'user_role_role_field' => 'role',
- };
+The Authorization::ACL plugin let's us declare where we'd like checks to be
+done automatically for us.
-To restrict access to any action, you can use the C<check_user_roles> method:
+For example, we may want to completely block out anyone who isn't a
+C<moose_feeder> from the entire C<MooseCage> controller:
- sub restricted : Local {
- my ( $self, $c ) = @_;
+ Zoo->deny_access_unless( "/moose_cage", [qw/moose_feeder/] );
- $c->detach("unauthorized")
- unless $c->check_user_roles( "admin" );
+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:
- # do something restricted here
- }
+ Zoo->deny_access_unless( "/moose_cage", sub {
+ my $c = shift;
+ $c->check_roles( "moose_trainer" ) || $c->check_roles( "moose_feeder" );
+ });
-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:
+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:
- sub also_restricted : Global {
- my ( $self, $c ) = @_;
- $c->assert_user_roles( qw/ user admin / );
- }
-
-=head2 Quick deployment: Building PAR Packages
+ Zoo->deny_access_unless( "/moose_cage", [qw/moose_trainer/] );
+ Zoo->allow_access_if( "/moose_cage/feed_moose", [qw/moose_feeder/]);
-You have an application running on your development box, but then you
-have to quickly move it to another one for
-demonstration/deployment/testing...
+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.
-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!
+Rules applied to the same path will be checked in the order they were added.
-=head3 Follow these few points to try it out!
+Lastly, handling access denial events is done by creating an C<access_denied>
+private action:
-1. Install Catalyst and PAR 0.89 (or later)
+ sub access_denied : Private {
+ my ( $self, $c, $action ) = @_;
- % perl -MCPAN -e 'install Catalyst'
- ...
- % perl -MCPAN -e 'install PAR'
- ...
+
+ }
-2. Create a application
+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.
- % catalyst.pl MyApp
- ...
- % cd MyApp
+If this action does not exist, an error will be thrown, which you can clean up
+in your C<end> private action instead.
-3. Add these lines to Makefile.PL (below "catalyst_files();")
+Also, it's important to note that if you restrict access to "/" then C<end>,
+C<default>, etc will also be restricted.
- catalyst_par_core(); # Include modules that are also included
- # in the standard Perl distribution,
- # this is optional but highly suggested
+ MyApp->acl_allow_root_internals;
- catalyst_par(); # Generate a PAR as soon as the blib
- # directory is ready
+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).
-4. Prepare the Makefile, test your app, create a PAR (the two
-Makefile.PL calls are no typo)
+=head1 Models
- % perl Makefile.PL
- ...
- % make test
- ...
- % perl Makefile.PL
- ...
+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.
-Recent versions of Catalyst include L<Module::Install::Catalyst>, which
-simplifies the process greatly.
+=head2 Using existing DBIC (etc.) classes with Catalyst
- % perl Makefile.PL
- ...
- % make catalyst_par
- ...
+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:
-Congratulations! Your package "myapp.par" is ready, the following
-steps are just optional.
+ 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;
-5. Test your PAR package with "parl" (no typo)
+and that's it! Now C<Some::DBIC::Schema> is part of your
+Cat app as C<MyApp::Model::DB>.
- % parl myapp.par
- Usage:
- [parl] myapp[.par] [script] [arguments]
+=head2 DBIx::Class as a Catalyst Model
- Examples:
- parl myapp.par myapp_server.pl -r
- myapp myapp_cgi.pl
+See L<Catalyst::Model::DBIC::Schema>.
- Available scripts:
- myapp_cgi.pl
- myapp_create.pl
- myapp_fastcgi.pl
- myapp_server.pl
- myapp_test.pl
+=head2 XMLRPC
- % parl myapp.par myapp_server.pl
- You can connect to your server at http://localhost:3000
+Unlike SOAP, XMLRPC is a very simple (and imo elegant) web-services
+protocol, exchanging small XML messages like these:
-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.
+Request:
-6. Want to create a binary that includes the Perl interpreter?
+ 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
- % pp -o myapp myapp.par
- % ./myapp myapp_server.pl
- You can connect to your server at http://localhost:3000
+ <?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>
-=head2 mod_perl Deployment
+Response:
-In today's entry, I'll be talking about deploying an application in
-production using Apache and mod_perl.
+ Connection: close
+ Date: Tue, 20 Dec 2005 07:45:55 GMT
+ Content-Length: 133
+ Content-Type: text/xml
+ Status: 200
+ X-Catalyst: 5.70
-=head3 Pros & Cons
+ <?xml version="1.0" encoding="us-ascii"?>
+ <methodResponse>
+ <params>
+ <param><value><int>3</int></value></param>
+ </params>
+ </methodResponse>
-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.
+Now follow these few steps to implement the application:
-=head4 Pros
+1. Install Catalyst (5.61 or later), Catalyst::Plugin::XMLRPC (0.06 or
+later) and SOAP::Lite (for XMLRPCsh.pl).
-=head4 Speed
+2. Create an application framework:
-mod_perl is very fast and your app will benefit from being loaded in memory
-within each Apache process.
+ % catalyst.pl MyApp
+ ...
+ % cd MyApp
-=head4 Shared memory for multiple apps
+3. Add the XMLRPC plugin to MyApp.pm
-If you need to run several Catalyst apps on the same server, mod_perl will
-share the memory for common modules.
+ use Catalyst qw/-Debug Static::Simple XMLRPC/;
-=head4 Cons
+4. Add an API controller
-=head4 Memory usage
+ % ./script/myapp_create.pl controller API
-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.
+5. Add a XMLRPC redispatch method and an add method with Remote
+attribute to lib/MyApp/Controller/API.pm
-=head4 Reloading
+ sub default : Private {
+ my ( $self, $c ) = @_;
+ $c->xmlrpc;
+ }
-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.
+ sub add : Remote {
+ my ( $self, $c, $a, $b ) = @_;
+ return $a + $b;
+ }
-=head4 Cannot run multiple versions of the same app
+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.
-It is not possible to run two different versions of the same application in
-the same Apache instance because the namespaces will collide.
+The C<add> method is not a traditional action; it has no private or
+public path. Only the XMLRPC dispatcher knows it exists.
-=head4 Setup
+6. That's it! You have built your first web service. Let's test it with
+XMLRPCsh.pl (part of SOAP::Lite):
-Now that we have that out of the way, let's talk about setting up mod_perl
-to run a Catalyst app.
+ % ./script/myapp_server.pl
+ ...
+ % XMLRPCsh.pl http://127.0.0.1:3000/api
+ Usage: method[(parameters)]
+ > add( 1, 2 )
+ --- XMLRPC RESULT ---
+ '3'
-=head4 1. Install Catalyst::Engine::Apache
+=head3 Tip
-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.
+Your return data type is usually auto-detected, but you can easily
+enforce a specific one.
-=head4 2. Install Apache with mod_perl
+ sub add : Remote {
+ my ( $self, $c, $a, $b ) = @_;
+ return RPC::XML::int->new( $a + $b );
+ }
+
-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.
-In Debian, the following commands should get you going.
+=head1 Views
- apt-get install apache2-mpm-prefork
- apt-get install libapache2-mod-perl2
+Views pertain to the display of your application. As with models,
+catalyst is uncommonly flexible. The recipes below are just a start.
-=head4 3. Configure your application
+=head2 Catalyst::View::TT
-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.
+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.
- PerlSwitches -I/var/www/MyApp/lib
- PerlModule MyApp
-
- <Location />
- SetHandler modperl
- PerlResponseHandler MyApp
- </Location>
+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.
-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.
+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.
-For an example Apache 1.3 configuration, please see the documentation for
-L<Catalyst::Engine::Apache::MP13>.
+=head3 Creating your View
-=head3 Test It
+Catalyst::View::TT provides two different helpers for us to use: TT and
+TTSite.
-That's it, your app is now a full-fledged mod_perl application! Try it out
-by going to http://your.server.com/.
+=head4 TT
-=head3 Other Options
+Create a basic Template Toolkit View using the provided helper script:
-=head4 Non-root location
+ script/myapp_create.pl view TT TT
-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.
+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:
- <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.
+ sub hello : Local {
+ my ( $self, $c ) = @_;
-=head4 Static file handling
+ $c->stash->{template} = 'hello.tt';
-Static files can be served directly by Apache for a performance boost.
+ $c->forward( $c->view('TT') );
+ }
- 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.
+In practice you wouldn't do the forwarding manually, but would
+use L<Catalyst::Action::RenderView>.
-=head2 Extending DefaultEnd
+=head4 TTSite
-Most people use L<Catalyst::Plugin::DefaultEnd> as their
-end action; it 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.
+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.
-Simply extend it like this:
+Once again, you can use the helper script:
- use Catalyst qw/DefaultEnd/;
+ script/myapp_create.pl view TT TTSite
- # (time passes)
+This time, the helper sets several options for us in the generated View.
- sub end : Private {
- my ( $self, $c ) = @_;
+ __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
+ });
- ... # code before view
+=over
- $c->NEXT::end( $c );
-
- ... # code after view
- }
-
-=head2 Catalyst on shared hosting
+=item
-So, you want to put your Catalyst app out there for the whole world to
-see, but you don't want to break the bank. There is an answer - if you
-can get shared hosting with FastCGI and a shell, you can install your
-Catalyst app in a local directory on your shared host. First, run
+INCLUDE_PATH defines the directories that Template Toolkit should search
+for the template files.
- perl -MCPAN -e shell
+=item
-and go through the standard CPAN configuration process. Then exit out
-without installing anything. Next, open your .bashrc and add
+PRE_PROCESS is used to process configuration options which are common to
+every template file.
- export PATH=$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:$PERL5LIB
+=item
-and log out, then back in again (or run C<". .bashrc"> if you
-prefer). Finally, edit C<.cpan/CPAN/MyConfig.pm> and add
+WRAPPER is a file which is processed with each template, usually used to
+easily provide a common header and footer for every page.
- 'make_install_arg' => qq[SITEPREFIX=$ENV{HOME}/local],
- 'makepl_arg' => qq[INSTALLDIRS=site install_base=$ENV{HOME}/local],
+=back
-Now you can install the modules you need using CPAN as normal; they
-will be installed into your local directory, and perl will pick them
-up. Finally, change directory into the root of your virtual host and
-symlink your application's script directory in:
+In addition to setting these options, the TTSite helper also created the
+template and config files for us! In the 'root' directory, you'll notice
+two new directories: src and lib.
- cd path/to/mydomain.com
- ln -s ~/lib/MyApp/script script
+Several configuration files in root/lib/config are called by PRE_PROCESS.
-And add the following lines to your .htaccess file (assuming the server
-is setup to handle .pl as fcgi - you may need to rename the script to
-myapp_fastcgi.fcgi and/or use a SetHandler directive):
+The files in root/lib/site are the site-wide templates, called by
+WRAPPER, and display the html framework, control the layout, and provide
+the templates for the header and footer of your page. Using the template
+organization provided makes it much easier to standardize pages and make
+changes when they are (inevitably) needed.
- RewriteEngine On
- RewriteCond %{REQUEST_URI} !^/?script/myapp_fastcgi.pl
- RewriteRule ^(.*)$ script/myapp_fastcgi.pl/$1 [PT,L]
+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.
-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 :) )
-=head2 Caching
+=head3 $c->stash
-Catalyst makes it easy to employ several different types of caching to
-speed up your applications.
+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.
-=head3 Cache Plugins
+In our controllers, we can add data to the stash, and then access it
+from the template. For instance:
-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.
+ sub hello : Local {
+ my ( $self, $c ) = @_;
-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.
+ $c->stash->{name} = 'Adam';
- 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;
+ $c->stash->{template} = 'hello.tt';
+
+ $c->forward( $c->view('TT') );
}
-
-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.
-=head3 Page Caching
+Then, in hello.tt:
-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.
+ <strong>Hello, [% name %]!</strong>
-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.
+When you view this page, it will display "Hello, Adam!"
- 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';
- }
+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.
-We can add the PageCache plugin to speed things up.
+In your controller:
- use Catalyst qw/Cache::FileCache PageCache/;
-
- sub front_page : Path ('/') {
+ sub hello : Local {
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.
-
-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.
-
-You can even get that front-end Squid proxy to help out by enabling HTTP
-headers for the cached page.
- MyApp->config->{page_cache}->{set_http_headers} = 1;
-
-This would now set the following headers so proxies and browsers may cache
-the content themselves.
+ $c->stash->{names} = [ 'Adam', 'Dave', 'John' ];
- Cache-Control: max-age=($expire_time - time)
- Expires: $expire_time
- Last-Modified: $cache_created_time
-
-=head3 Template Caching
+ $c->stash->{template} = 'hello.tt';
-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.
+ $c->forward( $c->view('TT') );
+ }
- package MyApp::View::TT;
-
- use strict;
- use warnings;
- use base 'Catalyst::View::TT';
-
- __PACKAGE__->config(
- COMPILE_DIR => '/tmp/template_cache',
- );
-
- 1;
-
-=head3 More Info
+In hello.tt:
-See the documentation for each cache plugin for more details and other
-available configuration options.
+ [% FOREACH name IN names %]
+ <strong>Hello, [% name %]!</strong><br />
+ [% END %]
-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>
+This allowed us to loop through each item in the arrayref, and display a
+line for each name that we have.
-=head2 Component-based Subrequests
+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.
-See L<Catalyst::Plugin::SubRequest>.
+=head3 $c->uri_for()
-=head2 DBIx::Class as a Catalyst Model
+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.
-See L<Catalyst::Model::DBIC::Schema>.
+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.
-=head2 Authentication/Authorization
+In your template, you can use the following:
-This is done in several steps:
+ <a href="[% c.uri_for('/login') %]">Login Here</a>
-=over 4
+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.
-=item Verification
+Likewise,
-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>.
+ <a href="[% c.uri_for('2005','10', '24') %]">October, 24 2005</a>
-=item Authorization
+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.
-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.
+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.
-=back
+Further Reading:
-=head3 Modules
+L<http://search.cpan.org/perldoc?Catalyst>
-The Catalyst Authentication system is made up of many interacting modules, to
-give you the most flexibility possible.
+L<http://search.cpan.org/perldoc?Catalyst%3A%3AView%3A%3ATT>
-=head4 Credential verifiers
+L<http://search.cpan.org/perldoc?Template>
-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<< $c->user >> call.
+=head2 Adding RSS feeds
-Examples:
+Adding RSS feeds to your Catalyst applications is simple. We'll see two
+different aproaches here, but the basic premise is that you forward to
+the normal view action first to get the objects, then handle the output
+differently.
- Password - Simple username/password checking.
- HTTPD - Checks using basic HTTP auth.
- TypeKey - Check using the typekey system.
+=head3 Using TT templates
-=head3 Storage backends
+This is the aproach used in Agave (L<http://dev.rawmode.org/>).
-A Storage backend contains the actual data representing the users. It is
-queried by the credential verifiers. Updating the store is not done within
-this system, you will need to do it yourself.
+ sub rss : Local {
+ my ($self,$c) = @_;
+ $c->forward('view');
+ $c->stash->{template}='rss.tt';
+ }
-Examples:
+Then you need a template. Here's the one from Agave:
- DBIC - Storage using a database.
- Minimal - Storage using a simple hash (for testing).
+ <?xml version="1.0" encoding="UTF-8"?>
+ <rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
+ <channel>
+ <title>[ [% blog.name || c.config.name || "Agave" %] ] RSS Feed</title>
+ <link>[% base %]</link>
+ <description>Recent posts</description>
+ <language>en-us</language>
+ <ttl>40</ttl>
+ [% WHILE (post = posts.next) %]
+ <item>
+ <title>[% post.title %]</title>
+ <description>[% post.formatted_teaser|html%]</description>
+ <pubDate>[% post.pub_date %]</pubDate>
+ <guid>[% post.full_uri %]</guid>
+ <link>[% post.full_uri %]</link>
+ <dc:creator>[% post.author.screenname %]</dc:creator>
+ </item>
+ [% END %]
+ </channel>
+ </rss>
-=head3 User objects
+=head3 Using XML::Feed
-A User object is created by either the storage backend or the credential
-verifier, and filled with the retrieved user information.
+A more robust solution is to use XML::Feed, as was done in the Catalyst
+Advent Calendar. Assuming we have a C<view> action that populates
+'entries' with some DBIx::Class iterator, the code would look something
+like this:
-Examples:
+ sub rss : Local {
+ my ($self,$c) = @_;
+ $c->forward('view'); # get the entries
- Hash - A simple hash of keys and values.
+ 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
-=head3 ACL authorization
+ # 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 );
+ }
-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.
+A little more code in the controller, but with this approach you're
+pretty sure to get something that validates.
-=head3 Roles authorization
+Note that for both of the above aproaches, you'll need to set the
+content type like this:
-Authorization by roles is for assigning users to groups, which can then be
-assigned to ACLs, or just checked when needed.
+ $c->res->content_type('application/rss+xml');
-=head3 Logging in
+=head3 Final words
-When you have chosen your modules, all you need to do is call the C<<
-$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.
+You could generalize the second variant easily by replacing 'RSS' with a
+variable, so you can generate Atom feeds with the same code.
-=head3 Checking roles
+Now, go ahead and make RSS feeds for all your stuff. The world *needs*
+updates on your goldfish!
-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.
+=head2 Forcing the browser to download content
+
+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.
+
+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>):
-=head3 EXAMPLE
+ sub export : Local Args(0) {
+ my ( $self, $c ) = @_;
- use Catalyst qw/Authentication
- Authentication::Credential::Password
- Authentication::Store::Htpasswd
- Authorization::Roles/;
+ # In a real application, you'd generate this from the database
+ my $csv = "1,5.99\n2,29.99\n3,3.99\n";
- __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
+ $c->res->content_type('text/comma-separated-values');
+ $c->res->body($csv);
+ }
- sub login : Local {
- my ($self, $c) = @_;
+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>.
- 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
- }
- }
+Luckily you can have the browser download the content with a specific
+filename by setting the C<Content-Disposition> header:
- sub restricted : Local {
- my ( $self, $c ) = @_;
+ my $filename = 'Important Orders.csv';
+ $c->res->header('Content-Disposition', qq[attachment; filename="$filename"]);
- $c->detach("unauthorized")
- unless $c->check_user_roles( "admin" );
+Note the use of quotes around the filename; this ensures that any
+spaces in the filename are handled by the browser.
- # do something restricted here
- }
+Put this right before calling C<< $c->res->body >> and your browser
+will download a file named C<Important Orders.csv> instead of
+C<export>.
-=head3 Using authentication in a testing environment
+You can also use this to have the browser download content which it
+normally displays, such as JPEG images or even HTML. Just be sure to
+set the appropriate content type and disposition.
-Ideally, to write tests for authentication/authorization code one would first
-set up a test database with known data, then use
-L<Test::WWW::Mechanize::Catalyst> to simulate a user logging in. Unfortunately
-the former can be rather awkward, which is why it's a good thing that the
-authentication framework is so flexible.
-Instead of using a test database, one can simply change the authentication
-store to something a bit easier to deal with in a testing
-environment. Additionally, this has the advantage of not modifying one's
-database, which can be problematic if one forgets to use the testing instead of
-production database.
+=head1 Controllers
-e.g.,
+Controllers are the main point of communication between the web server
+and your application. Here we explore some aspects of how they work.
- use Catalyst::Plugin::Authentication::Store::Minimal::Backend;
+=head2 Extending RenderView (formerly DefaultEnd)
- # Sets up the user `test_user' with password `test_pass'
- MyApp->default_auth_store(
- Catalyst::Plugin::Authentication::Store::Minimal::Backend->new({
- test_user => { password => 'test_pass' },
- })
- );
+The recommended approach for an C<end> action is to use
+L<Catalyst::Action::RenderView> (taking the place of
+L<Catalyst::Plugin::DefaultEnd>), which does what you usually need.
+However there are times when you need to add a bit to it, but don't want
+to write your own C<end> action.
-Now, your test code can call C<$c->login('test_user', 'test_pass')> and
-successfully login, without messing with the database at all.
+You can extend it like this:
-=head3 More information
+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:
-L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authentication> has a longer explanation.
+ sub end : ActionClass('RenderView') {
+ my ( $self, $c ) = @_;
+ # do stuff here; the RenderView action is called afterwards
+ }
-=head2 Sessions
+To add things to an C<end> action that are called I<after> rendering,
+you can set it up like this:
-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.
+ sub render : ActionClass('RenderView') { }
-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.
+ sub end : Private {
+ my ( $self, $c ) = @_;
+ $c->forward('render');
+ # do stuff here
+ }
+
+=head2 Action Types
-Catalyst uses two types of plugins to represent sessions:
+=head3 Introduction
-=head3 State
+A Catalyst application is driven by one or more Controller modules. There are
+a number of ways that Catalyst can decide which of the methods in your
+controller modules it should call. Controller methods are also called actions,
+because they determine how your catalyst application should (re-)act to any
+given URL. When the application is started up, catalyst looks at all your
+actions, and decides which URLs they map to.
-A State module is used to keep track of the state of the session between the
-users browser, and your application.
+=head3 Type attributes
-A common example is the Cookie state module, which sends the browser a cookie
-containing the session ID. It will use default value for the cookie name and
-domain, so will "just work" when used.
+Each action is a normal method in your controller, except that it has an
+L<attribute|http://search.cpan.org/~nwclark/perl-5.8.7/lib/attributes.pm>
+attached. These can be one of several types.
-=head3 Store
+Assume our Controller module starts with the following package declaration:
-A Store module is used to hold all the data relating to your session, for
-example the users ID, or the items for their shopping cart. You can store data
-in memory (FastMmap), in a file (File) or in a database (DBI).
+ package MyApp::Controller::Buckets;
-=head3 Authentication magic
+and we are running our application on localhost, port 3000 (the test
+server default).
-If you have included the session modules in your application, the
-Authentication modules will automagically use your session to save and
-retrieve the user data for you.
+=over 4
-=head3 Using a session
+=item Path
-Once the session modules are loaded, the session is available as C<<
-$c->session >>, and can be writen to and read from as a simple hash reference.
+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.
-=head3 EXAMPLE
+ sub my_handles : Path('handles') { .. }
- use Catalyst qw/
- Session
- Session::Store::FastMmap
- Session::State::Cookie
- /;
+becomes
+ http://localhost:3000/buckets/handles
- ## Write data into the session
+and
- sub add_item : Local {
- my ( $self, $c ) = @_;
+ sub my_handles : Path('/handles') { .. }
- my $item_id = $c->req->param("item");
+becomes
- push @{ $c->session->{items} }, $item_id;
+ http://localhost:3000/handles
- }
+=item Local
- ## A page later we retrieve the data from the session:
+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.
- sub get_items : Local {
- my ( $self, $c ) = @_;
+ sub my_handles : Local { .. }
- $c->stash->{items_to_display} = $c->session->{items};
+becomes
- }
+ http://localhost:3000/buckets/my_handles
+=item Global
-=head3 More information
+A Global attribute is similar to a Local attribute, except that the namespace
+of the controller is ignored, and matching starts at root.
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session>
+ sub my_handles : Global { .. }
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-Cookie>
+becomes
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-URI>
+ http://localhost:3000/my_handles
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-FastMmap>
+=item Regex
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-File>
+By now you should have figured that a Regex attribute is just what it sounds
+like. This one takes a regular expression, and matches starting from
+root. These differ from the rest as they can match multiple URLs.
+
+ sub my_handles : Regex('^handles') { .. }
+
+matches
-L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-DBI>
+ http://localhost:3000/handles
-=head2 Adding RSS feeds
+and
-Adding RSS feeds to your stuff in Catalyst is really simple. I'll show two
-different aproaches here, but the basic premise is that you forward to the
-normal view action first to get the objects, then handle the output differently
+ http://localhost:3000/handles_and_other_parts
-=head3 Using TT templates
+etc.
-This is the aproach we chose in Agave (L<http://dev.rawmode.org/>).
+=item LocalRegex
- sub rss : Local {
- my ($self,$c) = @_;
- $c->forward('view');
- $c->stash->{template}='rss.tt';
- }
+A LocalRegex is similar to a Regex, except it only matches below the current
+controller namespace.
-Then you need a template. Here's the one from Agave:
-L<http://svn.rawmode.org/repos/Agave/trunk/root/base/blog/rss.tt>
+ sub my_handles : LocalRegex(^handles') { .. }
-As you can see, it's pretty simple.
+matches
-=head3 Using XML::Feed
+ http://localhost:3000/buckets/handles
-However, a more robust solution is to use XML::Feed, as we've done in this
-Advent Calendar. Assuming we have a 'view' action that populates 'entries'
-with some DBIx::Class/Class::DBI iterator, the code would look something like
-this:
+and
- sub rss : Local {
- my ($self,$c) = @_;
- $c->forward('view'); # get the entries
+ http://localhost:3000/buckets/handles_and_other_parts
- 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
+etc.
- # 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 );
- }
+=item Private
+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.
-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:
+ sub my_handles : Private { .. }
- $c->res->content_type('application/rss+xml');
+becomes nothing at all..
-=head2 Final words
+Catalyst also predefines some special Private actions, which you can override,
+these are:
-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.
+=over 4
-Now, go ahead and make RSS feeds for all your stuff. The world *needs* updates
-on your goldfish!
+=item default
-=head2 FastCGI Deployment
+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 >>.
-As a companion to Day 7's mod_perl article, today's article is about
-production FastCGI deployment.
+ sub default : Private { .. }
-=head3 Pros
+works for all unknown URLs, in this controller namespace, or every one if put
+directly into MyApp.pm.
-=head4 Speed
+=item index
-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.
+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.
-=head4 App Server
+ sub index : Private { .. }
-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.
+becomes
-=head4 Load-balancing
+ http://localhost:3000/buckets
-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.
+=item begin
-=head4 Multiple versions of the same app
+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.
-Each FastCGI application is a separate process, so you can run different
-versions of the same app on a single server.
+ sub begin : Private { .. }
-=head4 Can run with threaded Apache
+is called once when
-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.
+ http://localhost:3000/bucket/(anything)?
-=head3 Cons
+is visited.
-=head4 More complex environment
+=item end
-With FastCGI, there are more things to monitor and more processes running
-than when using mod_perl.
+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.
-=head3 Setup
-=head4 1. Install Apache with mod_fastcgi
+ sub end : 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 after any actions 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 auto
-=head3 Standalone server mode
+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).
-While not as easy as the previous method, running your app as an external
-server gives you much more flexibility.
+ package MyApp.pm;
+ sub auto : Private { .. }
-First, launch your app as a standalone server listening on a socket.
+and
- 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.
+ sub auto : Private { .. }
- 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.
+will both be called when visiting
-Now, we simply configure Apache to connect to the running server.
+ http://localhost:3000/bucket/(anything)?
- # 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
+=back
- FastCgiExternalServer /tmp/myapp -socket /tmp/myapp.socket
- Alias /myapp/ /tmp/myapp/
-
- # Or, run at the root
- Alias / /tmp/myapp/
-
-=head3 More Info
+=back
-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>
+=head3 A word of warning
-=head2 Catalyst::View::TT
+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.
-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.
+=head3 More Information
-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.
+L<http://search.cpan.org/author/SRI/Catalyst-5.61/lib/Catalyst/Manual/Intro.pod>
-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.
+L<http://dev.catalyst.perl.org/wiki/FlowChart>
-=head3 Creating your View
+=head2 Component-based Subrequests
-Catalyst::View::TT provides two different helpers for use to use: TT and TTSite.
+See L<Catalyst::Plugin::SubRequest>.
-=head4 TT
+=head2 File uploads
-Create a basic Template Toolkit View using the provided helper script:
+=head3 Single file upload with Catalyst
- script/myapp_create.pl view TT TT
+To implement uploads in Catalyst, you need to have a HTML form similar to
+this:
-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:
+ <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>
- sub hello : Local {
- my ( $self, $c ) = @_;
+It's very important not to forget C<enctype="multipart/form-data"> in
+the form.
- $c->stash->{template} = 'hello.tt';
+Catalyst Controller module 'upload' action:
- $c->forward( $c->view('TT') );
- }
+ sub upload : Global {
+ my ($self, $c) = @_;
-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.
+ if ( $c->request->parameters->{form_submit} eq 'yes' ) {
-=head4 TTSite
+ if ( my $upload = $c->request->upload('my_file') ) {
-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.
+ my $filename = $upload->filename;
+ my $target = "/tmp/upload/$filename";
-Once again, you can use the helper script:
+ unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
+ die( "Failed to copy '$filename' to '$target': $!" );
+ }
+ }
+ }
- script/myapp_create.pl view TT TTSite
+ $c->stash->{template} = 'file_upload.html';
+ }
-This time, the helper sets several options for us in the generated View.
+=head3 Multiple file upload with Catalyst
- __PACKAGE__->config({
- CATALYST_VAR => 'Catalyst',
- INCLUDE_PATH => [
- MyApp->path_to( 'root', 'src' ),
- MyApp->path_to( 'root', 'lib' )
- ],
- PRE_PROCESS => 'config/main',
- WRAPPER => 'site/wrapper',
- ERROR => 'error.tt2',
- TIMER => 0
- });
+Code for uploading multiple files from one form needs a few changes:
-=over
+The form should have this basic structure:
-=item
-INCLUDE_PATH defines the directories that Template Toolkit should search for the template files.
+ <form action="/upload" method="post" enctype="multipart/form-data">
+ <input type="hidden" name="form_submit" value="yes">
+ <input type="file" name="file1" size="50"><br>
+ <input type="file" name="file2" size="50"><br>
+ <input type="file" name="file3" size="50"><br>
+ <input type="submit" value="Send">
+ </form>
-=item
-PRE_PROCESS is used to process configuration options which are common to every template file.
+And in the controller:
-=item
-WRAPPER is a file which is processed with each template, usually used to easily provide a common header and footer for every page.
+ sub upload : Local {
+ my ($self, $c) = @_;
-=back
+ if ( $c->request->parameters->{form_submit} eq 'yes' ) {
-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.
+ for my $field ( $c->req->upload ) {
-Several configuration files in root/lib/config are called by PRE_PROCESS.
+ my $upload = $c->req->upload($field);
+ my $filename = $upload->filename;
+ my $target = "/tmp/upload/$filename";
-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.
+ unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
+ die( "Failed to copy '$filename' to '$target': $!" );
+ }
+ }
+ }
-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.
+ $c->stash->{template} = 'file_upload.html';
+ }
-=head2 $c->stash
+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.
-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.
+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.
-In our controllers, we can add data to the stash, and then access it from the template. For instance:
+For more information about uploads and usable methods look at
+L<Catalyst::Request::Upload> and L<Catalyst::Request>.
- sub hello : Local {
- my ( $self, $c ) = @_;
+=head2 Forwarding with arguments
- $c->stash->{name} = 'Adam';
+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:
- $c->stash->{template} = 'hello.tt';
+ # version 5.30 and later:
+ $c->forward('/wherever', [qw/arg1 arg2 arg3/]);
- $c->forward( $c->view('TT') );
- }
+ # pre-5.30
+ $c->req->args([qw/arg1 arg2 arg3/]);
+ $c->forward('/wherever');
-Then, in hello.tt:
+(See the L<Catalyst::Manual::Intro> Flow_Control section for more
+information on passing arguments via C<forward>.)
- <strong>Hello, [% name %]!</strong>
-When you view this page, it will display "Hello, Adam!"
+=head1 Deployment
-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.
+The recipes below describe aspects of the deployment process,
+including web server engines and tips to improve application efficiency.
-In your controller:
+=head2 mod_perl Deployment
- sub hello : Local {
- my ( $self, $c ) = @_;
+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.
- $c->stash->{names} = [ 'Adam', 'Dave', 'John' ];
+=head3 Pros
- $c->stash->{template} = 'hello.tt';
+=head4 Speed
- $c->forward( $c->view('TT') );
- }
+mod_perl is very fast and your app will benefit from being loaded in memory
+within each Apache process.
-In hello.tt:
+=head4 Shared memory for multiple apps
- [% FOREACH name IN names %]
- <strong>Hello, [% name %]!</strong><br />
- [% END %]
+If you need to run several Catalyst apps on the same server, mod_perl will
+share the memory for common modules.
-This allowed us to loop through each item in the arrayref, and display a line for each name that we have.
+=head3 Cons
-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.
+=head4 Memory usage
-=head3 $c->uri_for()
+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.
-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 Reloading
-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.
+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.
-In your template, you can use the following:
+=head4 Cannot run multiple versions of the same app
- <a href="[% c.uri_for('/login') %]">Login Here</a>
+It is not possible to run two different versions of the same application in
+the same Apache instance because the namespaces will collide.
-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.
+=head4 Setup
-Likewise,
+Now that we have that out of the way, let's talk about setting up mod_perl
+to run a Catalyst app.
- <a href="[% c.uri_for('2005','10', '24') %]">October, 24 2005</a>
+=head4 1. Install Catalyst::Engine::Apache
-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.
+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.
-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.
+=head4 2. Install Apache with mod_perl
-Further Reading:
+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.
-L<http://search.cpan.org/perldoc?Catalyst>
+In Debian, the following commands should get you going.
-L<http://search.cpan.org/perldoc?Catalyst%3A%3AView%3A%3ATT>
+ apt-get install apache2-mpm-prefork
+ apt-get install libapache2-mod-perl2
-L<http://search.cpan.org/perldoc?Template>
+=head4 3. Configure your application
-=head2 Testing
+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.
-Catalyst provides a convenient way of testing your application during
-development and before deployment in a real environment.
+ PerlSwitches -I/var/www/MyApp/lib
+ PerlModule MyApp
+
+ <Location />
+ SetHandler modperl
+ PerlResponseHandler MyApp
+ </Location>
-C<Catalyst::Test> makes it possible to run the same tests both locally
-(without an external daemon) and against a remote server via HTTP.
+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.
-=head3 Tests
+For an example Apache 1.3 configuration, please see the documentation for
+L<Catalyst::Engine::Apache::MP13>.
-Let's examine a skeleton application's C<t/> directory:
+=head3 Test It
- 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
+That's it, your app is now a full-fledged mod_perl application! Try it out
+by going to http://your.server.com/.
-=over 4
+=head3 Other Options
-=item C<01app.t>
+=head4 Non-root location
-Verifies that the application loads, compiles, and returns a successful
-response.
+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.
-=item C<02pod.t>
+ <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.
-Verifies that all POD is free from errors. Only executed if the C<TEST_POD>
-environment variable is true.
+=head4 Static file handling
-=item C<03podcoverage.t>
+Static files can be served directly by Apache for a performance boost.
-Verifies that all methods/functions have POD coverage. Only executed if the
-C<TEST_POD> environment variable is true.
+ 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.
-=back
+=head2 Catalyst on shared hosting
-=head3 Creating tests
+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
- mundus:~/MyApp chansen$ cat t/01app.t | perl -ne 'printf( "%2d %s", $., $_ )'
- 1 use Test::More tests => 2;
- 2 use_ok( Catalyst::Test, 'MyApp' );
- 3
- 4 ok( request('/')->is_success );
+ perl -MCPAN -e shell
-The first line declares how many tests we are going to run, in this case
-two. The second line tests and loads our application in test mode. The
-fourth line verifies that our application returns a successful response.
+and go through the standard CPAN configuration process. Then exit out
+without installing anything. Next, open your .bashrc and add
-C<Catalyst::Test> exports two functions, C<request> and C<get>. Each can
-take three different arguments:
+ export PATH=$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:$PERL5LIB
-=over 4
+and log out, then back in again (or run C<". .bashrc"> if you
+prefer). Finally, edit C<.cpan/CPAN/MyConfig.pm> and add
-=item A string which is a relative or absolute URI.
+ 'make_install_arg' => qq[SITEPREFIX=$ENV{HOME}/local],
+ 'makepl_arg' => qq[INSTALLDIRS=site install_base=$ENV{HOME}/local],
- request('/my/path');
- request('http://www.host.com/my/path');
+Now you can install the modules you need using CPAN as normal; they
+will be installed into your local directory, and perl will pick them
+up. Finally, change directory into the root of your virtual host and
+symlink your application's script directory in:
-=item An instance of C<URI>.
+ cd path/to/mydomain.com
+ ln -s ~/lib/MyApp/script script
- request( URI->new('http://www.host.com/my/path') );
+And add the following lines to your .htaccess file (assuming the server
+is setup to handle .pl as fcgi - you may need to rename the script to
+myapp_fastcgi.fcgi and/or use a SetHandler directive):
-=item An instance of C<HTTP::Request>.
+ RewriteEngine On
+ RewriteCond %{REQUEST_URI} !^/?script/myapp_fastcgi.pl
+ RewriteRule ^(.*)$ script/myapp_fastcgi.pl/$1 [PT,L]
- request( HTTP::Request->new( GET => 'http://www.host.com/my/path') );
+Now C<http://mydomain.com/> should now Just Work. Congratulations, now
+you can tell your friends about your new website (or in our case, tell
+the client it's time to pay the invoice :) )
-=back
+=head2 FastCGI Deployment
-C<request> returns an instance of C<HTTP::Response> and C<get> returns the
-content (body) of the response.
+FastCGI is a high-performance extension to CGI. It is suitable
+for production environments.
-=head3 Running tests locally
+=head3 Pros
- mundus:~/MyApp chansen$ 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.
+=head4 Speed
-C<TEST_POD=1> enables POD checking and coverage.
+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.
-C<prove> A command-line tool that makes it easy to run tests. You can
-find out more about it from the links below.
+=head4 App Server
-=head3 Running tests remotely
+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.
- 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)
+=head4 Load-balancing
-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.
+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.
-=head3 C<Test::WWW::Mechanize> and Catalyst
+=head4 Multiple versions of the same app
-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:
+Each FastCGI application is a separate process, so you can run different
+versions of the same app on a single server.
- use Test::More tests => 6;
- use_ok( Test::WWW::Mechanize::Catalyst, 'MyApp' );
+=head4 Can run with threaded Apache
- 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' );
+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.
-=head3 Further Reading
+=head3 Cons
-=over 4
+=head4 More complex environment
-=item Catalyst::Test
+With FastCGI, there are more things to monitor and more processes running
+than when using mod_perl.
-L<http://search.cpan.org/dist/Catalyst/lib/Catalyst/Test.pm>
+=head3 Setup
-=item Test::WWW::Mechanize::Catalyst
+=head4 1. Install Apache with mod_fastcgi
-L<http://search.cpan.org/dist/Test-WWW-Mechanize-Catalyst/lib/Test/WWW/Mechanize/Catalyst.pm>
+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.
-=item Test::WWW::Mechanize
+=head4 2. Configure your application
-L<http://search.cpan.org/dist/Test-WWW-Mechanize/Mechanize.pm>
+ # Serve static content directly
+ DocumentRoot /var/www/MyApp/root
+ Alias /static /var/www/MyApp/root/static
-=item WWW::Mechanize
+ 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/
-L<http://search.cpan.org/dist/WWW-Mechanize/lib/WWW/Mechanize.pm>
+=head3 Standalone server mode
-=item LWP::UserAgent
+While not as easy as the previous method, running your app as an external
+server gives you much more flexibility.
-L<http://search.cpan.org/dist/libwww-perl/lib/LWP/UserAgent.pm>
+First, launch your app as a standalone server listening on a socket.
-=item HTML::Form
+ 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.
-L<http://search.cpan.org/dist/libwww-perl/lib/HTML/Form.pm>
+ 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.
-=item HTTP::Message
+Now, we simply configure Apache to connect to the running server.
-L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Message.pm>
+ # 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 HTTP::Request
+ FastCgiExternalServer /tmp/myapp -socket /tmp/myapp.socket
+ Alias /myapp/ /tmp/myapp/
+
+ # Or, run at the root
+ Alias / /tmp/myapp/
+
+=head3 More Info
-L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request.pm>
+L<Catalyst::Engine::FastCGI>.
-=item HTTP::Request::Common
+=head2 Quick deployment: Building PAR Packages
-L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request/Common.pm>
+You have an application running on your development box, but then you
+have to quickly move it to another one for
+demonstration/deployment/testing...
-=item HTTP::Response
+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!
-L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Response.pm>
+=head3 Follow these few points to try it out!
-=item HTTP::Status
+1. Install Catalyst and PAR 0.89 (or later)
-L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Status.pm>
+ % perl -MCPAN -e 'install Catalyst'
+ ...
+ % perl -MCPAN -e 'install PAR'
+ ...
-=item URI
+2. Create a application
-L<http://search.cpan.org/dist/URI/URI.pm>
+ % catalyst.pl MyApp
+ ...
+ % cd MyApp
-=item Test::More
+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:
-L<http://search.cpan.org/dist/Test-Simple/lib/Test/More.pm>
+ % perl Makefile.PL
+ % make catalyst_par
-=item Test::Pod
+Congratulations! Your package "myapp.par" is ready, the following
+steps are just optional.
-L<http://search.cpan.org/dist/Test-Pod/Pod.pm>
+3. Test your PAR package with "parl" (no typo)
-=item Test::Pod::Coverage
+ % parl myapp.par
+ Usage:
+ [parl] myapp[.par] [script] [arguments]
-L<http://search.cpan.org/dist/Test-Pod-Coverage/Coverage.pm>
+ Examples:
+ parl myapp.par myapp_server.pl -r
+ myapp myapp_cgi.pl
-=item prove (Test::Harness)
+ Available scripts:
+ myapp_cgi.pl
+ myapp_create.pl
+ myapp_fastcgi.pl
+ myapp_server.pl
+ myapp_test.pl
-L<http://search.cpan.org/dist/Test-Harness/bin/prove>
+ % parl myapp.par myapp_server.pl
+ You can connect to your server at http://localhost:3000
-=back
+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.
-=head2 XMLRPC
+6. Want to create a binary that includes the Perl interpreter?
-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.
+ % pp -o myapp myapp.par
+ % ./myapp myapp_server.pl
+ You can connect to your server at http://localhost:3000
-Request:
+=head2 Serving static content
- 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
+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.
- <?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>
+=head3 Introduction to Static::Simple
-Response:
+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.
- Connection: close
- Date: Tue, 20 Dec 2005 07:45:55 GMT
- Content-Length: 133
- Content-Type: text/xml
- Status: 200
- X-Catalyst: 5.62
+=head3 Usage
- <?xml version="1.0" encoding="us-ascii"?>
- <methodResponse>
- <params>
- <param><value><int>3</int></value></param>
- </params>
- </methodResponse>
+Using the plugin is as simple as setting your use line in MyApp.pm to include:
-Sweet little protocol, isn't it? :)
+ use Catalyst qw/Static::Simple/;
-Now follow these few steps to implement the application.
+and already files will be served.
-1. Install Catalyst (5.61 or later), Catalyst::Plugin::XMLRPC (0.06 or later) and SOAP::Lite (for XMLRPCsh.pl)
+=head3 Configuring
- % perl -MCPAN -e'install Catalyst'
- ...
- % perl -MCPAN -e'install Catalyst::Plugin::XMLRPC'
- ...
+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:
-2. Create a myapp
+ 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
- % catalyst.pl MyApp
- ...
- % cd MyApp
-3. Add the XMLRPC plugin to MyApp.pm
+All static content lives under C<root/static>, with everything else being
+Template Toolkit files.
- use Catalyst qw/-Debug Static::Simple XMLRPC/;
+=over 4
-4. Add a api controller
+=item Include Path
- % ./script/myapp_create.pl controller API
+You may of course want to change the default locations, and make
+Static::Simple look somewhere else, this is as easy as:
-5. Add a XMLRPC redispatch method and a add method with Remote attribute
-to lib/MyApp/Controller/API.pm
+ MyApp->config->{static}->{include_path} = [
+ MyApp->config->{root},
+ '/path/to/my/files'
+ ];
- sub default : Private {
- my ( $self, $c ) = @_;
- $c->xmlrpc;
- }
+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.
- sub add : Remote {
- my ( $self, $c, $a, $b ) = @_;
- return $a + $b;
- }
+=item Static directories
-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.
+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:
-The add method is no traditional action, it has no private or public path.
-Only the XMLRPC dispatcher knows it exists.
+ MyApp->config->{static}->{dirs} = [
+ 'static',
+ qr/^(images|css)/,
+ ];
-6. Thats it! You have built your first web service, lets test it with
-XMLRPCsh.pl (part of SOAP::Lite)
+=item File extensions
- % ./script/myapp_server.pl
- ...
- % XMLRPCsh.pl http://127.0.0.1:3000/api
- Usage: method[(parameters)]
- > add( 1, 2 )
- --- XMLRPC RESULT ---
- '3'
+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:
-=head3 Tip Of The Day
+ MyApp->config->{static}->{ignore_extensions} = [
+ qw/tmpl tt tt2 html xhtml/
+ ];
-Your return data type is usually auto-detected, but you can easily
-enforce a specific one.
+=item Ignoring directories
- sub add : Remote {
- my ( $self, $c, $a, $b ) = @_;
- return RPC::XML::int->new( $a + $b );
- }
-
-=head2 Action Types
+Entire directories can be ignored. If used with include_path,
+directories relative to the include_path dirs will also be ignored:
-=head3 Introduction
+ MyApp->config->{static}->{ignore_dirs} = [ qw/tmpl css/ ];
-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.
+=back
-=head3 Type attributes
+=head3 More information
-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.
+L<http://search.cpan.org/dist/Catalyst-Plugin-Static-Simple/>
-Assume our Controller module starts with the following package declaration:
+=head3 Serving manually with the Static plugin with HTTP::Daemon (myapp_server.pl)
- package MyApp::Controller::Buckets;
+In some situations you might want to control things more directly,
+using L<Catalyst::Plugin::Static>.
-and we are running our application on localhost, port 3000 (the test server default).
+In your main application class (MyApp.pm), load the plugin:
-=over 4
+ use Catalyst qw/-Debug FormValidator Static OtherPlugin/;
-=item Path
+You will also need to make sure your end method does I<not> forward
+static content to the view, perhaps like this:
-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.
+ sub end : Private {
+ my ( $self, $c ) = @_;
- sub my_handles : Path('handles') { .. }
+ $c->forward( 'MyApp::View::TT' )
+ unless ( $c->res->body || !$c->stash->{template} );
+ }
-becomes
+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>.
- http://localhost:3000/buckets/handles
+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>.
-and
+ $ script/myapp_create.pl controller Static
- sub my_handles : Path('/handles') { .. }
+Edit the file and add the following methods:
-becomes
+ # serve all files under /static as static files
+ sub default : Path('/static') {
+ my ( $self, $c ) = @_;
- http://localhost:3000/handles
+ # Optional, allow the browser to cache the content
+ $c->res->headers->header( 'Cache-Control' => 'max-age=86400' );
-=item Local
+ $c->serve_static; # from Catalyst::Plugin::Static
+ }
-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.
+ # also handle requests for /favicon.ico
+ sub favicon : Path('/favicon.ico') {
+ my ( $self, $c ) = @_;
- sub my_handles : Local { .. }
+ $c->serve_static;
+ }
-becomes
+You can also define a different icon for the browser to use instead of
+favicon.ico by using this in your HTML header:
- http://localhost:3000/buckets/my_handles
+ <link rel="icon" href="/static/myapp.ico" type="image/x-icon" />
-=item Global
+=head3 Common problems with the Static plugin
-A Global attribute is similar to a Local attribute, except that the namespace
-of the controller is ignored, and matching starts at root.
+The Static plugin makes use of the C<shared-mime-info> package to
+automatically determine MIME types. This package is notoriously
+difficult to install, especially on win32 and OS X. For OS X the easiest
+path might be to install Fink, then use C<apt-get install
+shared-mime-info>. Restart the server, and everything should be fine.
- sub my_handles : Global { .. }
+Make sure you are using the latest version (>= 0.16) for best
+results. If you are having errors serving CSS files, or if they get
+served as text/plain instead of text/css, you may have an outdated
+shared-mime-info version. You may also wish to simply use the following
+code in your Static controller:
-becomes
+ if ($c->req->path =~ /css$/i) {
+ $c->serve_static( "text/css" );
+ } else {
+ $c->serve_static;
+ }
- http://localhost:3000/my_handles
+=head3 Serving Static Files with Apache
-=item Regex
+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:
-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.
+ <Perl>
+ use lib qw(/var/www/MyApp/lib);
+ </Perl>
+ PerlModule MyApp
- sub my_handles : Regex('^handles') { .. }
+ <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>
-matches
+And here's a simpler example that'll get you started:
- http://localhost:3000/handles
+ Alias /static/ "/my/static/files/"
+ <Location "/static">
+ SetHandler none
+ </Location>
-and
+=head2 Caching
- http://localhost:3000/handles_and_other_parts
+Catalyst makes it easy to employ several different types of caching to
+speed up your applications.
-etc.
+=head3 Cache Plugins
-=item LocalRegex
+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.
-A LocalRegex is similar to a Regex, except it only matches below the current
-controller namespace.
+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.
- sub my_handles : LocalRegex(^handles') { .. }
+ 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.
-matches
+=head3 Page Caching
- http://localhost:3000/buckets/handles
+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.
-and
+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.
- http://localhost:3000/buckets/handles_and_other_parts
+ 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';
+ }
-etc.
+We can add the PageCache plugin to speed things up.
-=item Private
+ use Catalyst qw/Cache::FileCache PageCache/;
+
+ sub front_page : Path ('/') {
+ my ( $self, $c ) = @_;
+
+ $c->cache_page( 300 );
+
+ # same processing as above
+ }
+
+Now the entire output of the front page, from <html> to </html>, will be
+cached for 5 minutes. After 5 minutes, the next request will rebuild the
+page and it will be re-cached.
-Last but not least, there is the Private attribute, which allows you to create
-your own internal actions, which can be forwarded to, but won't be matched as
-URLs.
+Note that the page cache is keyed on the page URI plus all parameters, so
+requests for / and /?foo=bar will result in different cache items. Also,
+only GET requests will be cached by the plugin.
- sub my_handles : Private { .. }
+You can even get that front-end Squid proxy to help out by enabling HTTP
+headers for the cached page.
-becomes nothing at all..
+ MyApp->config->{page_cache}->{set_http_headers} = 1;
+
+This would now set the following headers so proxies and browsers may cache
+the content themselves.
-Catalyst also predefines some special Private actions, which you can override,
-these are:
+ Cache-Control: max-age=($expire_time - time)
+ Expires: $expire_time
+ Last-Modified: $cache_created_time
+
+=head3 Template Caching
-=over 4
+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.
-=item default
+ package MyApp::View::TT;
+
+ use strict;
+ use warnings;
+ use base 'Catalyst::View::TT';
+
+ __PACKAGE__->config(
+ COMPILE_DIR => '/tmp/template_cache',
+ );
+
+ 1;
+
+=head3 More Info
-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<< $c->req->path >>.
+See the documentation for each cache plugin for more details and other
+available configuration options.
- sub default : Private { .. }
+L<Catalyst::Plugin::Cache::FastMmap>
+L<Catalyst::Plugin::Cache::FileCache>
+L<Catalyst::Plugin::Cache::Memcached>
+L<Catalyst::Plugin::PageCache>
+L<http://search.cpan.org/dist/Template-Toolkit/lib/Template/Manual/Config.pod#Caching_and_Compiling_Options>
-works for all unknown URLs, in this controller namespace, or every one if put
-directly into MyApp.pm.
+=head1 Testing
-=item index
+Testing is an integral part of the web application development
+process. Tests make multi developer teams easier to coordinate, and
+they help ensure that there are no nasty surprises after upgrades or
+alterations.
-The index action is called when someone tries to visit the exact namespace of
-your controller. If index, default and matching Path actions are defined, then
-index will be used instead of default and Path.
+=head2 Testing
- sub index : Private { .. }
+Catalyst provides a convenient way of testing your application during
+development and before deployment in a real environment.
-becomes
+C<Catalyst::Test> makes it possible to run the same tests both locally
+(without an external daemon) and against a remote server via HTTP.
- http://localhost:3000/buckets
+=head3 Tests
-=item begin
+Let's examine a skeleton application's C<t/> directory:
-The begin action is called at the beginning of every request involving this
-namespace directly, before other matching actions are called. It can be used
-to set up variables/data for this particular part of your app. A single begin
-action is called, its always the one most relevant to the current namespace.
+ mundus:~/MyApp chansen$ 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
- sub begin : Private { .. }
+=over 4
-is called once when
+=item C<01app.t>
- http://localhost:3000/bucket/(anything)?
+Verifies that the application loads, compiles, and returns a successful
+response.
-is visited.
+=item C<02pod.t>
-=item end
+Verifies that all POD is free from errors. Only executed if the C<TEST_POD>
+environment variable is true.
-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.
+=item C<03podcoverage.t>
+Verifies that all methods/functions have POD coverage. Only executed if the
+C<TEST_POD> environment variable is true.
- sub end : Private { .. }
+=back
-is called once after any actions when
+=head3 Creating tests
- http://localhost:3000/bucket/(anything)?
+ mundus:~/MyApp chansen$ cat t/01app.t | perl -ne 'printf( "%2d %s", $., $_ )'
+ 1 use Test::More tests => 2;
+ 2 use_ok( Catalyst::Test, 'MyApp' );
+ 3
+ 4 ok( request('/')->is_success );
-is visited.
+The first line declares how many tests we are going to run, in this case
+two. The second line tests and loads our application in test mode. The
+fourth line verifies that our application returns a successful response.
-=item auto
+C<Catalyst::Test> exports two functions, C<request> and C<get>. Each can
+take three different arguments:
-Lastly, the auto action is magic in that B<every> auto action in
-the chain of paths up to and including the ending namespace, will be
-called. (In contrast, only one of the begin/end/default actions will be
-called, the relevant one).
+=over 4
- package MyApp.pm;
- sub auto : Private { .. }
+=item A string which is a relative or absolute URI.
-and
+ request('/my/path');
+ request('http://www.host.com/my/path');
- sub auto : Private { .. }
+=item An instance of C<URI>.
-will both be called when visiting
+ request( URI->new('http://www.host.com/my/path') );
- http://localhost:3000/bucket/(anything)?
+=item An instance of C<HTTP::Request>.
-=back
+ request( HTTP::Request->new( GET => 'http://www.host.com/my/path') );
=back
-=head3 A word of warning
-
-Due to possible namespace conflicts with Plugins, it is advised to only put the
-pre-defined Private actions in your main MyApp.pm file, all others should go
-in a Controller module.
-
-=head3 More Information
+C<request> returns an instance of C<HTTP::Response> and C<get> returns the
+content (body) of the response.
-L<http://search.cpan.org/author/SRI/Catalyst-5.61/lib/Catalyst/Manual/Intro.pod>
+=head3 Running tests locally
-L<http://dev.catalyst.perl.org/wiki/FlowChart>
+ mundus:~/MyApp chansen$ 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.
+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