=head2 Force debug screen
You can force Catalyst to display the debug screen at the end of the request by
-placing a die() call in the _end action.
+placing a C<die()> call in the C<end> action.
- __PACKAGE__->action(
- '!end' => sub {
- my ( $self, $c ) = @_;
- die "testing";
- }
- );
+ sub end : Private {
+ my ( $self, $c ) = @_;
+ die "forced debug";
+ }
If you're tired of removing and adding this all the time, you
-can easily add a condition. for example:
+can easily add a condition. For example:
- die "Testing" if $c->param->{dump_info};
+ die "force debug" if $c->req->params->{dump_info};
=head2 Disable statistics
=head2 Scaffolding
Scaffolding is very simple with Catalyst.
-Just use Catalyst::Model::CDBI::CRUD as baseclass.
+Just use Catalyst::Model::CDBI::CRUD as your base class.
# lib/MyApp/Model/CDBI.pm
package MyApp::Model::CDBI;
root => '/home/joeuser/myapp/root'
);
- __PACKAGE__->action(
- 'table' => sub {
- my ( $self, $c ) = @_;
- $c->form( optional => [ MyApp::Model::CDBI::Table->columns ] );
- $c->forward('MyApp::Model::CDBI::Table');
- }
- );
+ sub my_table : Global {
+ my ( $self, $c ) = @_;
+ $c->form( optional => [ MyApp::Model::CDBI::Table->columns ] );
+ $c->forward('MyApp::Model::CDBI::Table');
+ }
1;
Modify the $c->form() parameters to match your needs, and don't forget to copy
the templates. ;)
-=head2 Serving static files and CSS as text/css
-
-If you want to serve static content (like images, txt or CSS) via Catalyst,
-then all you need is the plugin Catalyst::Plugin::Static as well as a small
-regex to set the MIME type for CSS to text/css.
-
- # lib/MyApp.pm
- package MyApp;
-
- use strict;
- use Catalyst qw/-Debug Static/;
-
- __PACKAGE__->action(
-
- '!default' => sub {
- my ( $self, $c ) = @_;
- $c->serve_static;
- },
-
- '/^.*\.css$/' => sub {
- my ( $self, $c ) = @_;
- $c->serve_static('text/css');
- },
- );
-
-=head2 Uploads with Catalyst
+=head2 Single file upload with Catalyst
To implement uploads in Catalyst you need to have a HTML form similiar to
this:
<input type="submit" value="Send">
</form>
-It's very important not to forget enctype="multipart/form-data" in form,
-if it's not there, uploads just don't work.
+It's very important not to forget C<enctype="multipart/form-data"> in form. Uploads will not work without this.
Catalyst Controller module 'upload' action:
- MyApp->action(
-
- 'upload' => sub {
- my ($self, $c) = @_;
- if ($c->req->parameters->{form_submit} eq 'yes') {
- my $filename = $c->req->parameters->{my_file};
- if ($filename) {
- my $fh = $c->req->uploads->{$filename}->{fh};
- open(NEW_FILE, ">/tmp/$filename") or die
- "Can't open file for writing: $!";
- while ($fh->read(my $buf, 32768)) {
- print NEW_FILE $buf;
- }
- close(NEW_FILE);
+ sub upload : Global {
+ my ($self, $c) = @_;
+
+ if ( $c->request->parameters->{form_submit} eq 'yes' ) {
+
+ if ( my $upload = $c->request->upload('my_file') ) {
+
+ 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': $!" );
}
}
- $c->stash->{template} = 'upload_form.tt';
- $c->forward('MyApp::V::View');
- },
- );
+ }
+
+ $c->stash->{template} = 'file_upload.html';
+ }
+
+=head2 Multiple file upload with Catalyst
+
+Code for uploading multiple files from one form needs little changes compared
+to single file upload.
+
+Form goes like this:
-If you want to upload bigger files than 1MB, then just add to your Controller
-module:
+ <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>
- $CGI::Simple::POST_MAX = 1048576000;
+Controller:
+
+ sub upload : Local {
+ my ($self, $c) = @_;
+
+ if ( $c->request->parameters->{form_submit} eq 'yes' ) {
+
+ for my $field ( $c->req->upload ) {
+
+ 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': $!" );
+ }
+ }
+ }
+
+ $c->stash->{template} = 'file_upload.html';
+ }
+
+C<for my $field ($c-E<gt>req->upload)> loops automatically over all file input
+fields and gets input names. After that is basic file saving code, just like in
+single file upload.
+
+Notice: C<die>ing might not be what you want to do, when an error occurs, but
+it works as an example. A better idea would be to store error C<$!> in
+$c->stash->{error} and show a custom error template displaying this message.
+
+For more information about uploads and usable methods look at
+C<Catalyst::Request::Upload> and C<Catalyst::Request>.
=head2 Authentication with Catalyst::Plugin::Authentication::CDBI
There are (at least) two ways to implement authentication with this plugin:
-1) only checking username and password
+1) only checking username and password;
2) checking username, password and the roles the user has
For both variants you'll need the following code in your MyApp package:
'user_class' is a Class::DBI class for your users table.
'user_field' tells which field is used for username lookup (might be
-email, first name, surname etc).
+email, first name, surname etc.).
'password_field' is, well, password field in your table and by default
password is stored in plain text. Authentication::CDBI looks for 'user'
and 'password' fields in table, if they're not defined in the config.
-In PostgreSQL users table might be something like:
+In PostgreSQL, the users table might be something like:
-CREATE TABLE users (
- user_id serial,
- name varchar(100),
- surname varchar(100),
- password varchar(100),
- email varchar(100),
- primary key(user_id)
-);
+ CREATE TABLE users (
+ user_id serial,
+ name varchar(100),
+ surname varchar(100),
+ password varchar(100),
+ email varchar(100),
+ primary key(user_id)
+ );
We'll discuss the first variant for now:
-1. user:password login / auth without roles
+1. user:password login/auth without roles
-To log in a user you might use a action like this:
+To log in a user you might use an action like this:
- '?login' => sub {
+ sub login : Local {
my ($self, $c) = @_;
if ($c->req->params->{username}) {
$c->session_login($c->req->params->{username},
- $c->req->params->{password} );
+ $c->req->params->{password} );
if ($c->req->{user}) {
$c->forward('?restricted_area');
}
}
- },
+ }
+
+This action should not go in your MyApp class...if it does, it will
+conflict with the built-in method of the same name. Instead, put it
+in a Controller class.
$c->req->params->{username} and $c->req->params->{password} are html
-form parameters from a login form. If login succeeds, then $c->req->{user}
-contains the username of the authenticated user.
+form parameters from a login form. If login succeeds, then
+$c->req->{user} contains the username of the authenticated user.
-If you want to remember the users login status inbetween further requests,
-then just use the $c->session_login method, Catalyst will create a session
-id, session cookie and automatically append session id to all urls. So
-all you have to do, is just check $c->req->{user} where needed.
+If you want to remember the user's login status in between further
+requests, then just use the C<$c-E<gt>session_login> method. Catalyst will
+create a session id and session cookie and automatically append session
+id to all urls. So all you have to do is just check $c->req->{user}
+where needed.
-To log out user, just call $c->session_logout.
+To log out a user, just call $c->session_logout.
-Now lets take a look at the second variant:
-2. user:password login / auth with roles
+Now let's take a look at the second variant:
+2. user:password login/auth with roles
-To use roles you need to add to MyApp->config in the 'authentication'
-section following parameters:
+To use roles you need to add the following parameters to MyApp->config in the 'authentication' section:
role_class => 'MyApp::M::MyApp::Roles',
user_role_class => 'MyApp::M::MyApp::UserRoles',
Corresponding tables in PostgreSQL could look like this:
-CREATE TABLE roles (
- role_id serial,
- name varchar(100),
- primary key(role_id)
-);
-
-CREATE TABLE user_roles (
- user_role_id serial,
- user_id int,
- role_id int,
- primary key(user_role_id),
- foreign key(user_id) references users(user_id),
- foreign key(role_id) references roles(role_id)
-);
-
-The 'roles' table is a list of role names and the 'user_role' table is used for
-the user -> role lookup.
-
-Now if a logged in user wants to see a location which is allowed only for
-people with 'admin' role then in you controller you can check it with:
-
- '?add' => sub {
+ CREATE TABLE roles (
+ role_id serial,
+ name varchar(100),
+ primary key(role_id)
+ );
+
+ CREATE TABLE user_roles (
+ user_role_id serial,
+ user_id int,
+ role_id int,
+ primary key(user_role_id),
+ foreign key(user_id) references users(user_id),
+ foreign key(role_id) references roles(role_id)
+ );
+
+The 'roles' table is a list of role names and the 'user_role' table is
+used for the user -> role lookup.
+
+Now if a logged-in user wants to see a location which is allowed only
+for people with an 'admin' role, in your controller you can check it
+with:
+
+ sub add : Local {
my ($self, $c) = @_;
if ($c->roles(qw/admin/)) {
$c->req->output("Your account has the role 'admin.'");
} else {
- $c->req->output("You're not allowed to be here");
+ $c->req->output("You're not allowed to be here.");
}
- },
+ }
-One thing you might need is to forward non-authenticated users to login
-form, if they try to access restricted areas. If you want to do this
-controller-wide (if you have one controller for admin section) then it's
-best to add user check to '!begin' action:
+One thing you might need is to forward non-authenticated users to a login
+form if they try to access restricted areas. If you want to do this
+controller-wide (if you have one controller for your admin section) then it's
+best to add a user check to a '!begin' action:
- '!begin' => sub {
+ sub begin : Private {
my ($self, $c) = @_;
unless ($c->req->{user}) {
$c->req->action(undef); ## notice this!!
$c->forward('?login');
}
- },
-
-Pay attention to $c->req->action(undef). This is needed, because of the
-way $c->forward works - forward to login gets called, but after that
-Catalyst executes anyway the action defined in the uri (eg. if you tried to
-watch /add, then first '!begin' forwards to '?login', but after that
-anyway '?add' is executed). So $c->req->action(undef) undefines any
-actions that were to be called and forwards user where we want him/her
+ }
+
+Pay attention to $c->req->action(undef). This is needed because of the
+way $c->forward works - C<forward> to C<login> gets called, but after that
+Catalyst will still execute the action defined in the URI (e.g. if you
+tried to go to C</add>, then first 'begin' will forward to 'login', but after
+that 'add' will nonetheless be executed). So $c->req->action(undef) undefines any
+actions that were to be called and forwards the user where we want him/her
to be.
-And this is all you need to do, isn't Catalyst wonderful?
+And this is all you need to do.
+
+=head2 Pass-through login (and other actions)
+
+An easy way of having assorted actions that occur during the processing of
+a request that are orthogonal to its actual purpose - logins, silent
+commands etc. Provide actions for these, but when they're required for
+something else fill e.g. a form variable __login and have a sub begin like so:
+
+sub begin : Private {
+ my ($self, $c) = @_;
+ foreach my $action (qw/login docommand foo bar whatever/) {
+ if ($c->req->params->{"__${action}"}) {
+ $c->forward($action);
+ }
+ }
+}
+
+=head2 How to use Catalyst without mod_perl
+
+Catalyst applications give optimum performance when run under mod_perl.
+However sometimes mod_perl is not an option, and running under CGI is
+just too slow. There's also an alternative to mod_perl that gives
+reasonable performance named FastCGI.
+
+B<Using FastCGI>
+
+To quote from L<http://www.fastcgi.com/>: "FastCGI is a language
+independent, scalable, extension to CGI that provides high performance
+without the limitations of specific server APIs." Web server support
+is provided for Apache in the form of C<mod_fastcgi> and there is Perl
+support in the C<FCGI> module. To convert a CGI Catalyst application
+to FastCGI one needs to initialize an C<FCGI::Request> object and loop
+while the C<Accept> method returns zero. The following code shows how
+it is done - and it also works as a normal, single-shot CGI script.
+
+ #!/usr/bin/perl
+ use strict;
+ use FCGI;
+ use MyApp;
+
+ my $request = FCGI::Request();
+ while ($request->Accept() >= 0) {
+ MyApp->run;
+ }
+
+Any initialization code should be included outside the request-accept
+loop.
+
+There is one little complication, which is that C<MyApp-E<gt>run> outputs a
+complete HTTP response including the status line (e.g.:
+"C<HTTP/1.1 200>").
+FastCGI just wants a set of headers, so the sample code captures the
+output and drops the first line if it is an HTTP status line (note:
+this may change).
+
+The Apache C<mod_fastcgi> module is provided by a number of Linux
+distros and is straightforward to compile for most Unix-like systems.
+The module provides a FastCGI Process Manager, which manages FastCGI
+scripts. You configure your script as a FastCGI script with the
+following Apache configuration directives:
+
+ <Location /fcgi-bin>
+ AddHandler fastcgi-script fcgi
+ </Location>
+
+or:
+
+ <Location /fcgi-bin>
+ SetHandler fastcgi-script
+ Action fastcgi-script /path/to/fcgi-bin/fcgi-script
+ </Location>
+
+C<mod_fastcgi> provides a number of options for controlling the FastCGI
+scripts spawned; it also allows scripts to be run to handle the
+authentication, authorization, and access check phases.
+
+For more information see the FastCGI documentation, the C<FCGI> module
+and L<http://www.fastcgi.com/>.
+
+=head1 Forwarding with a parameter
+
+Sometimes you want to pass along arguments when forwarding to another
+action. This can easily be accomplished like this:
+
+ $c->req->args([qw/arg1 arg2 arg3/]);
+ $c->forward('/wherever');
=head1 AUTHOR
Sebastian Riedel, C<sri@oook.de>
Danijel Milicevic C<me@danijel.de>
Viljo Marrandi C<vilts@yahoo.com>
+Marcus Ramberg C<mramberg@cpan.org>
=head1 COPYRIGHT
-This program is free software, you can redistribute it and/or modify it under
-the same terms as Perl itself.
+This program is free software, you can redistribute it and/or modify it
+under the same terms as Perl itself.