4 Catalyst::Manual::Cookbook - Cooking with Catalyst
8 Yummy code like your mum used to bake!
12 =head2 Force debug screen
14 You can force Catalyst to display the debug screen at the end of the
15 request by placing a C<die()> call in the C<end> action.
18 my ( $self, $c ) = @_;
22 If you're tired of removing and adding this all the time, you can add a
23 condition in the C<end> action. For example:
26 my ( $self, $c ) = @_;
27 die "forced debug" if $c->req->params->{dump_info};
30 Then just add to your query string C<&dump_info=1> (or if there's no
31 query string for the request, add C<?dump_info=1> to the end of the URL)
32 to force debug output. This feature is included in
33 L<Catalyst::Action::RenderView> (formerly
34 L<Catalyst::Plugin::DefaultEnd>).
37 =head2 Disable statistics
39 Just add this line to your application class if you don't want those nifty
40 statistics in your debug messages.
42 sub Catalyst::Log::info { }
44 =head2 Enable debug status in the environment
46 Normally you enable the debugging info by adding the C<-Debug> flag to
47 your C<use Catalyst> statement. However, you can also enable it using
48 environment variable, so you can (for example) get debug info without
49 modifying your application scripts. Just set C<CATALYST_DEBUG> or
50 C<E<lt>MYAPPE<gt>_DEBUG> to a true value.
54 =head3 Single file upload with Catalyst
56 To implement uploads in Catalyst, you need to have a HTML form similar to
59 <form action="/upload" method="post" enctype="multipart/form-data">
60 <input type="hidden" name="form_submit" value="yes">
61 <input type="file" name="my_file">
62 <input type="submit" value="Send">
65 It's very important not to forget C<enctype="multipart/form-data"> in
68 Catalyst Controller module 'upload' action:
73 if ( $c->request->parameters->{form_submit} eq 'yes' ) {
75 if ( my $upload = $c->request->upload('my_file') ) {
77 my $filename = $upload->filename;
78 my $target = "/tmp/upload/$filename";
80 unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
81 die( "Failed to copy '$filename' to '$target': $!" );
86 $c->stash->{template} = 'file_upload.html';
89 =head3 Multiple file upload with Catalyst
91 Code for uploading multiple files from one form needs a few changes:
93 The form should have this basic structure:
95 <form action="/upload" method="post" enctype="multipart/form-data">
96 <input type="hidden" name="form_submit" value="yes">
97 <input type="file" name="file1" size="50"><br>
98 <input type="file" name="file2" size="50"><br>
99 <input type="file" name="file3" size="50"><br>
100 <input type="submit" value="Send">
103 And in the controller:
108 if ( $c->request->parameters->{form_submit} eq 'yes' ) {
110 for my $field ( $c->req->upload ) {
112 my $upload = $c->req->upload($field);
113 my $filename = $upload->filename;
114 my $target = "/tmp/upload/$filename";
116 unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
117 die( "Failed to copy '$filename' to '$target': $!" );
122 $c->stash->{template} = 'file_upload.html';
125 C<for my $field ($c-E<gt>req->upload)> loops automatically over all file
126 input fields and gets input names. After that is basic file saving code,
127 just like in single file upload.
129 Notice: C<die>ing might not be what you want to do, when an error
130 occurs, but it works as an example. A better idea would be to store
131 error C<$!> in $c->stash->{error} and show a custom error template
132 displaying this message.
134 For more information about uploads and usable methods look at
135 L<Catalyst::Request::Upload> and L<Catalyst::Request>.
137 =head2 Authentication (logging in)
139 This is extensively covered in other documentation; see in particular
140 L<Catalyst::Plugin::Authentication> and the Authentication chapter
141 of the Tutorial at L<Catalyst::Manual::Tutorial::Authorization>.
143 =head2 Pass-through login (and other actions)
145 An easy way of having assorted actions that occur during the processing
146 of a request that are orthogonal to its actual purpose - logins, silent
147 commands etc. Provide actions for these, but when they're required for
148 something else fill e.g. a form variable __login and have a sub begin
151 sub begin : Private {
153 foreach my $action (qw/login docommand foo bar whatever/) {
154 if ($c->req->params->{"__${action}"}) {
155 $c->forward($action);
161 =head2 Serving static content
163 Serving static content in Catalyst used to be somewhat tricky; the use
164 of L<Catalyst::Plugin::Static::Simple> makes everything much easier.
165 This plugin will automatically serve your static content during development,
166 but allows you to easily switch to Apache (or other server) in a
167 production environment.
169 =head3 Introduction to Static::Simple
171 Static::Simple is a plugin that will help to serve static content for your
172 application. By default, it will serve most types of files, excluding some
173 standard Template Toolkit extensions, out of your B<root> file directory. All
174 files are served by path, so if B<images/me.jpg> is requested, then
175 B<root/images/me.jpg> is found and served.
179 Using the plugin is as simple as setting your use line in MyApp.pm to include:
181 use Catalyst qw/Static::Simple/;
183 and already files will be served.
187 Static content is best served from a single directory within your root
188 directory. Having many different directories such as C<root/css> and
189 C<root/images> requires more code to manage, because you must separately
190 identify each static directory--if you decide to add a C<root/js>
191 directory, you'll need to change your code to account for it. In
192 contrast, keeping all static directories as subdirectories of a main
193 C<root/static> directory makes things much easier to manage. Here's an
194 example of a typical root directory structure:
198 root/controller/stuff.tt
201 root/static/css/main.css
202 root/static/images/logo.jpg
203 root/static/js/code.js
206 All static content lives under C<root/static>, with everything else being
207 Template Toolkit files.
213 You may of course want to change the default locations, and make
214 Static::Simple look somewhere else, this is as easy as:
216 MyApp->config->{static}->{include_path} = [
217 MyApp->config->{root},
221 When you override include_path, it will not automatically append the
222 normal root path, so you need to add it yourself if you still want
223 it. These will be searched in order given, and the first matching file
226 =item Static directories
228 If you want to force some directories to be only static, you can set
229 them using paths relative to the root dir, or regular expressions:
231 MyApp->config->{static}->{dirs} = [
236 =item File extensions
238 By default, the following extensions are not served (that is, they will
239 be processed by Catalyst): B<tmpl, tt, tt2, html, xhtml>. This list can
242 MyApp->config->{static}->{ignore_extensions} = [
243 qw/tmpl tt tt2 html xhtml/
246 =item Ignoring directories
248 Entire directories can be ignored. If used with include_path,
249 directories relative to the include_path dirs will also be ignored:
251 MyApp->config->{static}->{ignore_dirs} = [ qw/tmpl css/ ];
255 =head3 More information
257 L<http://search.cpan.org/dist/Catalyst-Plugin-Static-Simple/>
259 =head3 Serving manually with the Static plugin with HTTP::Daemon (myapp_server.pl)
261 In some situations you might want to control things more directly,
262 using L<Catalyst::Plugin::Static>.
264 In your main application class (MyApp.pm), load the plugin:
266 use Catalyst qw/-Debug FormValidator Static OtherPlugin/;
268 You will also need to make sure your end method does I<not> forward
269 static content to the view, perhaps like this:
272 my ( $self, $c ) = @_;
274 $c->forward( 'MyApp::View::TT' )
275 unless ( $c->res->body || !$c->stash->{template} );
278 This code will only forward to the view if a template has been
279 previously defined by a controller and if there is not already data in
280 C<$c-E<gt>res-E<gt>body>.
282 Next, create a controller to handle requests for the /static path. Use
283 the Helper to save time. This command will create a stub controller as
284 C<lib/MyApp/Controller/Static.pm>.
286 $ script/myapp_create.pl controller Static
288 Edit the file and add the following methods:
290 # serve all files under /static as static files
291 sub default : Path('/static') {
292 my ( $self, $c ) = @_;
294 # Optional, allow the browser to cache the content
295 $c->res->headers->header( 'Cache-Control' => 'max-age=86400' );
297 $c->serve_static; # from Catalyst::Plugin::Static
300 # also handle requests for /favicon.ico
301 sub favicon : Path('/favicon.ico') {
302 my ( $self, $c ) = @_;
307 You can also define a different icon for the browser to use instead of
308 favicon.ico by using this in your HTML header:
310 <link rel="icon" href="/static/myapp.ico" type="image/x-icon" />
312 =head3 Common problems with the Static plugin
314 The Static plugin makes use of the C<shared-mime-info> package to
315 automatically determine MIME types. This package is notoriously
316 difficult to install, especially on win32 and OS X. For OS X the easiest
317 path might be to install Fink, then use C<apt-get install
318 shared-mime-info>. Restart the server, and everything should be fine.
320 Make sure you are using the latest version (>= 0.16) for best
321 results. If you are having errors serving CSS files, or if they get
322 served as text/plain instead of text/css, you may have an outdated
323 shared-mime-info version. You may also wish to simply use the following
324 code in your Static controller:
326 if ($c->req->path =~ /css$/i) {
327 $c->serve_static( "text/css" );
332 =head3 Serving Static Files with Apache
334 When using Apache, you can bypass Catalyst and any Static
335 plugins/controllers controller by intercepting requests for the
336 C<root/static> path at the server level. All that is required is to
337 define a DocumentRoot and add a separate Location block for your static
338 content. Here is a complete config for this application under mod_perl
342 use lib qw(/var/www/MyApp/lib);
347 ServerName myapp.example.com
348 DocumentRoot /var/www/MyApp/root
350 SetHandler perl-script
353 <LocationMatch "/(static|favicon.ico)">
354 SetHandler default-handler
358 And here's a simpler example that'll get you started:
360 Alias /static/ "/my/static/files/"
365 =head2 Forwarding with arguments
367 Sometimes you want to pass along arguments when forwarding to another
368 action. As of version 5.30, arguments can be passed in the call to
369 C<forward>; in earlier versions, you can manually set the arguments in
370 the Catalyst Request object:
372 # version 5.30 and later:
373 $c->forward('/wherever', [qw/arg1 arg2 arg3/]);
376 $c->req->args([qw/arg1 arg2 arg3/]);
377 $c->forward('/wherever');
379 (See the L<Catalyst::Manual::Intro> Flow_Control section for more
380 information on passing arguments via C<forward>.)
382 =head2 Configure your application
384 You configure your application with the C<config> method in your
385 application class. This can be hard-coded, or brought in from a
386 separate configuration file.
390 YAML is a method for creating flexible and readable configuration
391 files. It's a great way to keep your Catalyst application configuration
392 in one easy-to-understand location.
394 In your application class (e.g. C<lib/MyApp.pm>):
398 __PACKAGE__->config( YAML::LoadFile(__PACKAGE__->config->{'home'} . '/myapp.yml') );
401 Now create C<myapp.yml> in your application home:
404 # DO NOT USE TABS FOR INDENTATION OR label/value SEPARATION!!!
407 # session; perldoc Catalyst::Plugin::Session::FastMmap
411 storage: '/tmp/myapp.session'
413 # emails; perldoc Catalyst::Plugin::Email
414 # this passes options as an array :(
419 This is equivalent to:
421 # configure base package
422 __PACKAGE__->config( name => MyApp );
423 # configure authentication
424 __PACKAGE__->config->{authentication} = {
425 user_class => 'MyApp::Model::MyDB::Customer',
429 __PACKAGE__->config->{session} = {
433 # configure email sending
434 __PACKAGE__->config->{email} = [qw/SMTP localhost/];
438 =head2 Using existing DBIC (etc.) classes with Catalyst
440 Many people have existing Model classes that they would like to use with
441 Catalyst (or, conversely, they want to write Catalyst models that can be
442 used outside of Catalyst, e.g. in a cron job). It's trivial to write a
443 simple component in Catalyst that slurps in an outside Model:
445 package MyApp::Model::DB;
446 use base qw/Catalyst::Model::DBIC::Schema/;
448 schema_class => 'Some::DBIC::Schema',
449 connect_info => ['dbi:SQLite:foo.db', '', '', {AutoCommit=>1}];
453 and that's it! Now C<Some::DBIC::Schema> is part of your
454 Cat app as C<MyApp::Model::DB>.
456 =head2 Delivering a Custom Error Page
458 By default, Catalyst will display its own error page whenever it
459 encounters an error in your application. When running under C<-Debug>
460 mode, the error page is a useful screen including the error message and
461 L<Data::Dump> output of the relevant parts of the C<$c> context object.
462 When not in C<-Debug>, users see a simple "Please come back later" screen.
464 To use a custom error page, use a special C<end> method to short-circuit
465 the error processing. The following is an example; you might want to
466 adjust it further depending on the needs of your application (for
467 example, any calls to C<fillform> will probably need to go into this
468 C<end> method; see L<Catalyst::Plugin::FillInForm>).
471 my ( $self, $c ) = @_;
473 if ( scalar @{ $c->error } ) {
474 $c->stash->{errors} = $c->error;
475 $c->stash->{template} = 'errors.tt';
476 $c->forward('MyApp::View::TT');
480 return 1 if $c->response->status =~ /^3\d\d$/;
481 return 1 if $c->response->body;
483 unless ( $c->response->content_type ) {
484 $c->response->content_type('text/html; charset=utf-8');
487 $c->forward('MyApp::View::TT');
490 You can manually set errors in your code to trigger this page by calling
492 $c->error( 'You broke me!' );
494 =head2 Role-based Authorization
496 For more advanced access control, you may want to consider using role-based
497 authorization. This means you can assign different roles to each user, e.g.
498 "user", "admin", etc.
500 The C<login> and C<logout> methods and view template are exactly the same as
501 in the previous example.
503 The L<Catalyst::Plugin::Authorization::Roles> plugin is required when
508 Authentication::Credential::Password
509 Authentication::Store::Htpasswd
513 Roles are implemented automatically when using
514 L<Catalyst::Authentication::Store::Htpasswd>:
516 # no additional role configuration required
517 __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
519 Or can be set up manually when using L<Catalyst::Authentication::Store::DBIC>:
521 # Authorization using a many-to-many role relationship
522 __PACKAGE__->config->{authorization}{dbic} = {
523 'role_class' => 'My::Model::DBIC::Role',
524 'role_field' => 'name',
525 'user_role_user_field' => 'user',
527 # DBIx::Class only (omit if using Class::DBI)
528 'role_rel' => 'user_role',
530 # Class::DBI only, (omit if using DBIx::Class)
531 'user_role_class' => 'My::Model::CDBI::UserRole'
532 'user_role_role_field' => 'role',
535 To restrict access to any action, you can use the C<check_user_roles> method:
537 sub restricted : Local {
538 my ( $self, $c ) = @_;
540 $c->detach("unauthorized")
541 unless $c->check_user_roles( "admin" );
543 # do something restricted here
546 You can also use the C<assert_user_roles> method. This just gives an error if
547 the current user does not have one of the required roles:
549 sub also_restricted : Global {
550 my ( $self, $c ) = @_;
551 $c->assert_user_roles( qw/ user admin / );
554 =head2 Quick deployment: Building PAR Packages
556 You have an application running on your development box, but then you
557 have to quickly move it to another one for
558 demonstration/deployment/testing...
560 PAR packages can save you from a lot of trouble here. They are usual Zip
561 files that contain a blib tree; you can even include all prereqs and a
562 perl interpreter by setting a few flags!
564 =head3 Follow these few points to try it out!
566 1. Install Catalyst and PAR 0.89 (or later)
568 % perl -MCPAN -e 'install Catalyst'
570 % perl -MCPAN -e 'install PAR'
573 2. Create a application
579 Recent versions of Catalyst (5.62 and up) include
580 L<Module::Install::Catalyst>, which simplifies the process greatly. From the shell in your application directory:
585 Congratulations! Your package "myapp.par" is ready, the following
586 steps are just optional.
588 3. Test your PAR package with "parl" (no typo)
592 [parl] myapp[.par] [script] [arguments]
595 parl myapp.par myapp_server.pl -r
605 % parl myapp.par myapp_server.pl
606 You can connect to your server at http://localhost:3000
608 Yes, this nifty little starter application gets automatically included.
609 You can also use "catalyst_par_script('myapp_server.pl')" to set a
610 default script to execute.
612 6. Want to create a binary that includes the Perl interpreter?
614 % pp -o myapp myapp.par
615 % ./myapp myapp_server.pl
616 You can connect to your server at http://localhost:3000
618 =head2 mod_perl Deployment
622 mod_perl is the best solution for many applications, but I'll list some pros
623 and cons so you can decide for yourself. The other production deployment
624 option is FastCGI, which I'll talk about in a future calendar article.
630 mod_perl is very fast and your app will benefit from being loaded in memory
631 within each Apache process.
633 =head4 Shared memory for multiple apps
635 If you need to run several Catalyst apps on the same server, mod_perl will
636 share the memory for common modules.
642 Since your application is fully loaded in memory, every Apache process will
643 be rather large. This means a large Apache process will be tied up while
644 serving static files, large files, or dealing with slow clients. For this
645 reason, it is best to run a two-tiered web architecture with a lightweight
646 frontend server passing dynamic requests to a large backend mod_perl
651 Any changes made to the core code of your app require a full Apache restart.
652 Catalyst does not support Apache::Reload or StatINC. This is another good
653 reason to run a frontend web server where you can set up an
654 C<ErrorDocument 502> page to report that your app is down for maintenance.
656 =head4 Cannot run multiple versions of the same app
658 It is not possible to run two different versions of the same application in
659 the same Apache instance because the namespaces will collide.
663 Now that we have that out of the way, let's talk about setting up mod_perl
664 to run a Catalyst app.
666 =head4 1. Install Catalyst::Engine::Apache
668 You should install the latest versions of both Catalyst and
669 Catalyst::Engine::Apache. The Apache engines were separated from the
670 Catalyst core in version 5.50 to allow for updates to the engine without
671 requiring a new Catalyst release.
673 =head4 2. Install Apache with mod_perl
675 Both Apache 1.3 and Apache 2 are supported, although Apache 2 is highly
676 recommended. With Apache 2, make sure you are using the prefork MPM and not
677 the worker MPM. The reason for this is that many Perl modules are not
678 thread-safe and may have problems running within the threaded worker
679 environment. Catalyst is thread-safe however, so if you know what you're
680 doing, you may be able to run using worker.
682 In Debian, the following commands should get you going.
684 apt-get install apache2-mpm-prefork
685 apt-get install libapache2-mod-perl2
687 =head4 3. Configure your application
689 Every Catalyst application will automagically become a mod_perl handler
690 when run within mod_perl. This makes the configuration extremely easy.
691 Here is a basic Apache 2 configuration.
693 PerlSwitches -I/var/www/MyApp/lib
698 PerlResponseHandler MyApp
701 The most important line here is C<PerlModule MyApp>. This causes mod_perl
702 to preload your entire application into shared memory, including all of your
703 controller, model, and view classes and configuration. If you have -Debug
704 mode enabled, you will see the startup output scroll by when you first
707 For an example Apache 1.3 configuration, please see the documentation for
708 L<Catalyst::Engine::Apache::MP13>.
712 That's it, your app is now a full-fledged mod_perl application! Try it out
713 by going to http://your.server.com/.
717 =head4 Non-root location
719 You may not always want to run your app at the root of your server or virtual
720 host. In this case, it's a simple change to run at any non-root location
725 PerlResponseHandler MyApp
728 When running this way, it is best to make use of the C<uri_for> method in
729 Catalyst for constructing correct links.
731 =head4 Static file handling
733 Static files can be served directly by Apache for a performance boost.
735 DocumentRoot /var/www/MyApp/root
737 SetHandler default-handler
740 This will let all files within root/static be handled directly by Apache. In
741 a two-tiered setup, the frontend server should handle static files.
742 The configuration to do this on the frontend will vary.
744 =head2 Extending RenderView (formerly DefaultEnd)
746 The recommended approach for an C<end> action is to use
747 L<Catalyst::Action::RenderView> (taking the place of
748 L<Catalyst::Plugin::DefaultEnd>), which does what you usually need.
749 However there are times when you need to add a bit to it, but don't want
750 to write your own C<end> action.
752 You can extend it like this:
754 To add something to an C<end> action that is called before rendering
755 (this is likely to be what you want), simply place it in the C<end>
758 sub end : ActionClass('RenderView') {
759 my ( $self, $c ) = @_;
760 # do stuff here; the RenderView action is called afterwards
763 To add things to an C<end> action that are called I<after> rendering,
764 you can set it up like this:
766 sub render : ActionClass('RenderView') { }
769 my ( $self, $c ) = @_;
770 $c->forward('render');
774 =head2 Catalyst on shared hosting
776 So, you want to put your Catalyst app out there for the whole world to
777 see, but you don't want to break the bank. There is an answer - if you
778 can get shared hosting with FastCGI and a shell, you can install your
779 Catalyst app in a local directory on your shared host. First, run
783 and go through the standard CPAN configuration process. Then exit out
784 without installing anything. Next, open your .bashrc and add
786 export PATH=$HOME/local/bin:$HOME/local/script:$PATH
787 perlversion=`perl -v | grep 'built for' | awk '{print $4}' | sed -e 's/v//;'`
788 export PERL5LIB=$HOME/local/share/perl/$perlversion:$HOME/local/lib/perl/$perlversion:$HOME/local/lib:$PERL5LIB
790 and log out, then back in again (or run C<". .bashrc"> if you
791 prefer). Finally, edit C<.cpan/CPAN/MyConfig.pm> and add
793 'make_install_arg' => qq[SITEPREFIX=$ENV{HOME}/local],
794 'makepl_arg' => qq[INSTALLDIRS=site install_base=$ENV{HOME}/local],
796 Now you can install the modules you need using CPAN as normal; they
797 will be installed into your local directory, and perl will pick them
798 up. Finally, change directory into the root of your virtual host and
799 symlink your application's script directory in:
801 cd path/to/mydomain.com
802 ln -s ~/lib/MyApp/script script
804 And add the following lines to your .htaccess file (assuming the server
805 is setup to handle .pl as fcgi - you may need to rename the script to
806 myapp_fastcgi.fcgi and/or use a SetHandler directive):
809 RewriteCond %{REQUEST_URI} !^/?script/myapp_fastcgi.pl
810 RewriteRule ^(.*)$ script/myapp_fastcgi.pl/$1 [PT,L]
812 Now C<http://mydomain.com/> should now Just Work. Congratulations, now
813 you can tell your friends about your new website (or in our case, tell
814 the client it's time to pay the invoice :) )
818 Catalyst makes it easy to employ several different types of caching to
819 speed up your applications.
823 There are three wrapper plugins around common CPAN cache modules:
824 Cache::FastMmap, Cache::FileCache, and Cache::Memcached. These can be
825 used to cache the result of slow operations.
827 This very page you're viewing makes use of the FileCache plugin to cache the
828 rendered XHTML version of the source POD document. This is an ideal
829 application for a cache because the source document changes infrequently but
830 may be viewed many times.
832 use Catalyst qw/Cache::FileCache/;
837 sub render_pod : Local {
838 my ( self, $c ) = @_;
840 # the cache is keyed on the filename and the modification time
841 # to check for updates to the file.
842 my $file = $c->path_to( 'root', '2005', '11.pod' );
843 my $mtime = ( stat $file )->mtime;
845 my $cached_pod = $c->cache->get("$file $mtime");
846 if ( !$cached_pod ) {
847 $cached_pod = do_slow_pod_rendering();
848 # cache the result for 12 hours
849 $c->cache->set( "$file $mtime", $cached_pod, '12h' );
851 $c->stash->{pod} = $cached_pod;
854 We could actually cache the result forever, but using a value such as 12 hours
855 allows old entries to be automatically expired when they are no longer needed.
859 Another method of caching is to cache the entire HTML page. While this is
860 traditionally handled by a front-end proxy server like Squid, the Catalyst
861 PageCache plugin makes it trivial to cache the entire output from
862 frequently-used or slow actions.
864 Many sites have a busy content-filled front page that might look something
865 like this. It probably takes a while to process, and will do the exact same
866 thing for every single user who views the page.
868 sub front_page : Path('/') {
869 my ( $self, $c ) = @_;
871 $c->forward( 'get_news_articles' );
872 $c->forward( 'build_lots_of_boxes' );
873 $c->forward( 'more_slow_stuff' );
875 $c->stash->{template} = 'index.tt';
878 We can add the PageCache plugin to speed things up.
880 use Catalyst qw/Cache::FileCache PageCache/;
882 sub front_page : Path ('/') {
883 my ( $self, $c ) = @_;
885 $c->cache_page( 300 );
887 # same processing as above
890 Now the entire output of the front page, from <html> to </html>, will be
891 cached for 5 minutes. After 5 minutes, the next request will rebuild the
892 page and it will be re-cached.
894 Note that the page cache is keyed on the page URI plus all parameters, so
895 requests for / and /?foo=bar will result in different cache items. Also,
896 only GET requests will be cached by the plugin.
898 You can even get that front-end Squid proxy to help out by enabling HTTP
899 headers for the cached page.
901 MyApp->config->{page_cache}->{set_http_headers} = 1;
903 This would now set the following headers so proxies and browsers may cache
904 the content themselves.
906 Cache-Control: max-age=($expire_time - time)
907 Expires: $expire_time
908 Last-Modified: $cache_created_time
910 =head3 Template Caching
912 Template Toolkit provides support for caching compiled versions of your
913 templates. To enable this in Catalyst, use the following configuration.
914 TT will cache compiled templates keyed on the file mtime, so changes will
915 still be automatically detected.
917 package MyApp::View::TT;
921 use base 'Catalyst::View::TT';
924 COMPILE_DIR => '/tmp/template_cache',
931 See the documentation for each cache plugin for more details and other
932 available configuration options.
934 L<Catalyst::Plugin::Cache::FastMmap>
935 L<Catalyst::Plugin::Cache::FileCache>
936 L<Catalyst::Plugin::Cache::Memcached>
937 L<Catalyst::Plugin::PageCache>
938 L<http://search.cpan.org/dist/Template-Toolkit/lib/Template/Manual/Config.pod#Caching_and_Compiling_Options>
940 =head2 Component-based Subrequests
942 See L<Catalyst::Plugin::SubRequest>.
944 =head2 DBIx::Class as a Catalyst Model
946 See L<Catalyst::Model::DBIC::Schema>.
948 =head2 Authentication/Authorization
950 This is done in several steps:
956 Getting the user to identify themselves, by giving you some piece of
957 information known only to you and the user. Then you can assume that the user
958 is who they say they are. This is called B<credential verification>.
962 Making sure the user only accesses functions you want them to access. This is
963 done by checking the verified users data against your internal list of groups,
964 or allowed persons for the current page.
970 The Catalyst Authentication system is made up of many interacting modules, to
971 give you the most flexibility possible.
973 =head4 Credential verifiers
975 A Credential module tables the user input, and passes it to a Store, or some
976 other system, for verification. Typically, a user object is created by either
977 this module or the Store and made accessible by a C<< $c->user >> call.
981 Password - Simple username/password checking.
982 HTTPD - Checks using basic HTTP auth.
983 TypeKey - Check using the typekey system.
985 =head3 Storage backends
987 A Storage backend contains the actual data representing the users. It is
988 queried by the credential verifiers. Updating the store is not done within
989 this system, you will need to do it yourself.
993 DBIC - Storage using a database.
994 Minimal - Storage using a simple hash (for testing).
998 A User object is created by either the storage backend or the credential
999 verifier, and filled with the retrieved user information.
1003 Hash - A simple hash of keys and values.
1005 =head3 ACL authorization
1007 ACL stands for Access Control List. The ACL plugin allows you to regulate
1008 access on a path by path basis, by listing which users, or roles, have access
1011 =head3 Roles authorization
1013 Authorization by roles is for assigning users to groups, which can then be
1014 assigned to ACLs, or just checked when needed.
1018 When you have chosen your modules, all you need to do is call the C<<
1019 $c->login >> method. If called with no parameters, it will try to find
1020 suitable parameters, such as B<username> and B<password>, or you can pass it
1023 =head3 Checking roles
1025 Role checking is done by using the C<< $c->check_user_roles >> method, this will
1026 check using the currently logged in user (via C<< $c->user >>). You pass it
1027 the name of a role to check, and it returns true if the user is a member.
1031 use Catalyst qw/Authentication
1032 Authentication::Credential::Password
1033 Authentication::Store::Htpasswd
1034 Authorization::Roles/;
1036 __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
1039 my ($self, $c) = @_;
1041 if ( my $user = $c->req->param("user")
1042 and my $password = $c->req->param("password") )
1044 if ( $c->login( $user, $password ) ) {
1045 $c->res->body( "hello " . $c->user->name );
1051 # invalid form input
1055 sub restricted : Local {
1056 my ( $self, $c ) = @_;
1058 $c->detach("unauthorized")
1059 unless $c->check_user_roles( "admin" );
1061 # do something restricted here
1064 =head3 Using authentication in a testing environment
1066 Ideally, to write tests for authentication/authorization code one would first
1067 set up a test database with known data, then use
1068 L<Test::WWW::Mechanize::Catalyst> to simulate a user logging in. Unfortunately
1069 the former can be rather awkward, which is why it's a good thing that the
1070 authentication framework is so flexible.
1072 Instead of using a test database, one can simply change the authentication
1073 store to something a bit easier to deal with in a testing
1074 environment. Additionally, this has the advantage of not modifying one's
1075 database, which can be problematic if one forgets to use the testing instead of
1076 production database.
1080 use Catalyst::Plugin::Authentication::Store::Minimal::Backend;
1082 # Sets up the user `test_user' with password `test_pass'
1083 MyApp->default_auth_store(
1084 Catalyst::Plugin::Authentication::Store::Minimal::Backend->new({
1085 test_user => { password => 'test_pass' },
1089 Now, your test code can call C<$c->login('test_user', 'test_pass')> and
1090 successfully login, without messing with the database at all.
1092 =head3 More information
1094 L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authentication> has a longer explanation.
1098 When you have your users identified, you will want to somehow remember that
1099 fact, to save them from having to identify themselves for every single
1100 page. One way to do this is to send the username and password parameters in
1101 every single page, but that's ugly, and won't work for static pages.
1103 Sessions are a method of saving data related to some transaction, and giving
1104 the whole collection a single ID. This ID is then given to the user to return
1105 to us on every page they visit while logged in. The usual way to do this is
1106 using a browser cookie.
1108 Catalyst uses two types of plugins to represent sessions:
1112 A State module is used to keep track of the state of the session between the
1113 users browser, and your application.
1115 A common example is the Cookie state module, which sends the browser a cookie
1116 containing the session ID. It will use default value for the cookie name and
1117 domain, so will "just work" when used.
1121 A Store module is used to hold all the data relating to your session, for
1122 example the users ID, or the items for their shopping cart. You can store data
1123 in memory (FastMmap), in a file (File) or in a database (DBI).
1125 =head3 Authentication magic
1127 If you have included the session modules in your application, the
1128 Authentication modules will automagically use your session to save and
1129 retrieve the user data for you.
1131 =head3 Using a session
1133 Once the session modules are loaded, the session is available as C<<
1134 $c->session >>, and can be writen to and read from as a simple hash reference.
1140 Session::Store::FastMmap
1141 Session::State::Cookie
1145 ## Write data into the session
1147 sub add_item : Local {
1148 my ( $self, $c ) = @_;
1150 my $item_id = $c->req->param("item");
1152 push @{ $c->session->{items} }, $item_id;
1156 ## A page later we retrieve the data from the session:
1158 sub get_items : Local {
1159 my ( $self, $c ) = @_;
1161 $c->stash->{items_to_display} = $c->session->{items};
1166 =head3 More information
1168 L<http://search.cpan.org/dist/Catalyst-Plugin-Session>
1170 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-Cookie>
1172 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-URI>
1174 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-FastMmap>
1176 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-File>
1178 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-DBI>
1180 =head2 Adding RSS feeds
1182 Adding RSS feeds to your Catalyst applications is simple. We'll see two
1183 different aproaches here, but the basic premise is that you forward to
1184 the normal view action first to get the objects, then handle the output
1187 =head3 Using TT templates
1189 This is the aproach used in Agave (L<http://dev.rawmode.org/>).
1193 $c->forward('view');
1194 $c->stash->{template}='rss.tt';
1197 Then you need a template. Here's the one from Agave:
1199 <?xml version="1.0" encoding="UTF-8"?>
1200 <rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
1202 <title>[ [% blog.name || c.config.name || "Agave" %] ] RSS Feed</title>
1203 <link>[% base %]</link>
1204 <description>Recent posts</description>
1205 <language>en-us</language>
1207 [% WHILE (post = posts.next) %]
1209 <title>[% post.title %]</title>
1210 <description>[% post.formatted_teaser|html%]</description>
1211 <pubDate>[% post.pub_date %]</pubDate>
1212 <guid>[% post.full_uri %]</guid>
1213 <link>[% post.full_uri %]</link>
1214 <dc:creator>[% post.author.screenname %]</dc:creator>
1220 =head3 Using XML::Feed
1222 A more robust solution is to use XML::Feed, as was done in the Catalyst
1223 Advent Calendar. Assuming we have a C<view> action that populates
1224 'entries' with some DBIx::Class iterator, the code would look something
1229 $c->forward('view'); # get the entries
1231 my $feed = XML::Feed->new('RSS');
1232 $feed->title( $c->config->{name} . ' RSS Feed' );
1233 $feed->link( $c->req->base ); # link to the site.
1234 $feed->description('Catalyst advent calendar'); Some description
1236 # Process the entries
1237 while( my $entry = $c->stash->{entries}->next ) {
1238 my $feed_entry = XML::Feed::Entry->new('RSS');
1239 $feed_entry->title($entry->title);
1240 $feed_entry->link( $c->uri_for($entry->link) );
1241 $feed_entry->issued( DateTime->from_epoch(epoch => $entry->created) );
1242 $feed->add_entry($feed_entry);
1244 $c->res->body( $feed->as_xml );
1247 A little more code in the controller, but with this approach you're
1248 pretty sure to get something that validates.
1250 Note that for both of the above aproaches, you'll need to set the
1251 content type like this:
1253 $c->res->content_type('application/rss+xml');
1257 You could generalize the second variant easily by replacing 'RSS' with a
1258 variable, so you can generate Atom feeds with the same code.
1260 Now, go ahead and make RSS feeds for all your stuff. The world *needs*
1261 updates on your goldfish!
1263 =head2 FastCGI Deployment
1265 FastCGI is a high-performance extension to CGI. It is suitable
1266 for production environments.
1272 FastCGI performs equally as well as mod_perl. Don't let the 'CGI' fool you;
1273 your app runs as multiple persistent processes ready to receive connections
1274 from the web server.
1278 When using external FastCGI servers, your application runs as a standalone
1279 application server. It may be restarted independently from the web server.
1280 This allows for a more robust environment and faster reload times when
1281 pushing new app changes. The frontend server can even be configured to
1282 display a friendly "down for maintenance" page while the application is
1285 =head4 Load-balancing
1287 You can launch your application on multiple backend servers and allow the
1288 frontend web server to load-balance between all of them. And of course, if
1289 one goes down, your app continues to run fine.
1291 =head4 Multiple versions of the same app
1293 Each FastCGI application is a separate process, so you can run different
1294 versions of the same app on a single server.
1296 =head4 Can run with threaded Apache
1298 Since your app is not running inside of Apache, the faster mpm_worker module
1299 can be used without worrying about the thread safety of your application.
1303 =head4 More complex environment
1305 With FastCGI, there are more things to monitor and more processes running
1306 than when using mod_perl.
1310 =head4 1. Install Apache with mod_fastcgi
1312 mod_fastcgi for Apache is a third party module, and can be found at
1313 L<http://www.fastcgi.com/>. It is also packaged in many distributions,
1314 for example, libapache2-mod-fastcgi in Debian.
1316 =head4 2. Configure your application
1318 # Serve static content directly
1319 DocumentRoot /var/www/MyApp/root
1320 Alias /static /var/www/MyApp/root/static
1322 FastCgiServer /var/www/MyApp/script/myapp_fastcgi.pl -processes 3
1323 Alias /myapp/ /var/www/MyApp/script/myapp_fastcgi.pl/
1325 # Or, run at the root
1326 Alias / /var/www/MyApp/script/myapp_fastcgi.pl/
1328 The above commands will launch 3 app processes and make the app available at
1331 =head3 Standalone server mode
1333 While not as easy as the previous method, running your app as an external
1334 server gives you much more flexibility.
1336 First, launch your app as a standalone server listening on a socket.
1338 script/myapp_fastcgi.pl -l /tmp/myapp.socket -n 5 -p /tmp/myapp.pid -d
1340 You can also listen on a TCP port if your web server is not on the same
1343 script/myapp_fastcgi.pl -l :8080 -n 5 -p /tmp/myapp.pid -d
1345 You will probably want to write an init script to handle starting/stopping
1346 of the app using the pid file.
1348 Now, we simply configure Apache to connect to the running server.
1350 # 502 is a Bad Gateway error, and will occur if the backend server is down
1351 # This allows us to display a friendly static page that says "down for
1353 Alias /_errors /var/www/MyApp/root/error-pages
1354 ErrorDocument 502 /_errors/502.html
1356 FastCgiExternalServer /tmp/myapp -socket /tmp/myapp.socket
1357 Alias /myapp/ /tmp/myapp/
1359 # Or, run at the root
1364 L<Catalyst::Engine::FastCGI>.
1366 =head2 Catalyst::View::TT
1368 One of the first things you probably want to do when starting a new
1369 Catalyst application is set up your View. Catalyst doesn't care how you
1370 display your data; you can choose to generate HTML, PDF files, or plain
1373 Most Catalyst applications use a template system to generate their HTML,
1374 and though there are several template systems available, Template
1375 Toolkit is probably the most popular.
1377 Once again, the Catalyst developers have done all the hard work, and
1378 made things easy for the rest of us. Catalyst::View::TT provides the
1379 interface to Template Toolkit, and provides Helpers which let us set it
1380 up that much more easily.
1382 =head3 Creating your View
1384 Catalyst::View::TT provides two different helpers for us to use: TT and
1389 Create a basic Template Toolkit View using the provided helper script:
1391 script/myapp_create.pl view TT TT
1393 This will create lib/MyApp/View/MyView.pm, which is going to be pretty
1394 empty to start. However, it sets everything up that you need to get
1395 started. You can now define which template you want and forward to your
1399 my ( $self, $c ) = @_;
1401 $c->stash->{template} = 'hello.tt';
1403 $c->forward( $c->view('TT') );
1406 In practice you wouldn't do the forwarding manually, but would
1407 use L<Catalyst::Action::RenderView>.
1411 Although the TT helper does create a functional, working view, you may
1412 find yourself having to create the same template files and changing the
1413 same options every time you create a new application. The TTSite helper
1414 saves us even more time by creating the basic templates and setting some
1415 common options for us.
1417 Once again, you can use the helper script:
1419 script/myapp_create.pl view TT TTSite
1421 This time, the helper sets several options for us in the generated View.
1423 __PACKAGE__->config({
1424 CATALYST_VAR => 'Catalyst',
1426 MyApp->path_to( 'root', 'src' ),
1427 MyApp->path_to( 'root', 'lib' )
1429 PRE_PROCESS => 'config/main',
1430 WRAPPER => 'site/wrapper',
1431 ERROR => 'error.tt2',
1439 INCLUDE_PATH defines the directories that Template Toolkit should search
1440 for the template files.
1444 PRE_PROCESS is used to process configuration options which are common to
1445 every template file.
1449 WRAPPER is a file which is processed with each template, usually used to
1450 easily provide a common header and footer for every page.
1454 In addition to setting these options, the TTSite helper also created the
1455 template and config files for us! In the 'root' directory, you'll notice
1456 two new directories: src and lib.
1458 Several configuration files in root/lib/config are called by PRE_PROCESS.
1460 The files in root/lib/site are the site-wide templates, called by
1461 WRAPPER, and display the html framework, control the layout, and provide
1462 the templates for the header and footer of your page. Using the template
1463 organization provided makes it much easier to standardize pages and make
1464 changes when they are (inevitably) needed.
1466 The template files that you will create for your application will go
1467 into root/src, and you don't need to worry about putting the the <html>
1468 or <head> sections; just put in the content. The WRAPPER will the rest
1469 of the page around your template for you.
1473 Of course, having the template system include the header and footer for
1474 you isn't all that we want our templates to do. We need to be able to
1475 put data into our templates, and have it appear where and how we want
1476 it, right? That's where the stash comes in.
1478 In our controllers, we can add data to the stash, and then access it
1479 from the template. For instance:
1482 my ( $self, $c ) = @_;
1484 $c->stash->{name} = 'Adam';
1486 $c->stash->{template} = 'hello.tt';
1488 $c->forward( $c->view('TT') );
1493 <strong>Hello, [% name %]!</strong>
1495 When you view this page, it will display "Hello, Adam!"
1497 All of the information in your stash is available, by its name/key, in
1498 your templates. And your data don't have to be plain, old, boring
1499 scalars. You can pass array references and hash references, too.
1504 my ( $self, $c ) = @_;
1506 $c->stash->{names} = [ 'Adam', 'Dave', 'John' ];
1508 $c->stash->{template} = 'hello.tt';
1510 $c->forward( $c->view('TT') );
1515 [% FOREACH name IN names %]
1516 <strong>Hello, [% name %]!</strong><br />
1519 This allowed us to loop through each item in the arrayref, and display a
1520 line for each name that we have.
1522 This is the most basic usage, but Template Toolkit is quite powerful,
1523 and allows you to truly keep your presentation logic separate from the
1524 rest of your application.
1526 =head3 $c->uri_for()
1528 One of my favorite things about Catalyst is the ability to move an
1529 application around without having to worry that everything is going to
1530 break. One of the areas that used to be a problem was with the http
1531 links in your template files. For example, suppose you have an
1532 application installed at http://www.domain.com/Calendar. The links point
1533 to "/Calendar", "/Calendar/2005", "/Calendar/2005/10", etc. If you move
1534 the application to be at http://www.mydomain.com/Tools/Calendar, then
1535 all of those links will suddenly break.
1537 That's where $c->uri_for() comes in. This function will merge its
1538 parameters with either the base location for the app, or its current
1539 namespace. Let's take a look at a couple of examples.
1541 In your template, you can use the following:
1543 <a href="[% c.uri_for('/login') %]">Login Here</a>
1545 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.
1549 <a href="[% c.uri_for('2005','10', '24') %]">October, 24 2005</a>
1551 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.
1553 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.
1557 L<http://search.cpan.org/perldoc?Catalyst>
1559 L<http://search.cpan.org/perldoc?Catalyst%3A%3AView%3A%3ATT>
1561 L<http://search.cpan.org/perldoc?Template>
1565 Catalyst provides a convenient way of testing your application during
1566 development and before deployment in a real environment.
1568 C<Catalyst::Test> makes it possible to run the same tests both locally
1569 (without an external daemon) and against a remote server via HTTP.
1573 Let's examine a skeleton application's C<t/> directory:
1575 mundus:~/MyApp chansen$ ls -l t/
1577 -rw-r--r-- 1 chansen chansen 95 18 Dec 20:50 01app.t
1578 -rw-r--r-- 1 chansen chansen 190 18 Dec 20:50 02pod.t
1579 -rw-r--r-- 1 chansen chansen 213 18 Dec 20:50 03podcoverage.t
1585 Verifies that the application loads, compiles, and returns a successful
1590 Verifies that all POD is free from errors. Only executed if the C<TEST_POD>
1591 environment variable is true.
1593 =item C<03podcoverage.t>
1595 Verifies that all methods/functions have POD coverage. Only executed if the
1596 C<TEST_POD> environment variable is true.
1600 =head3 Creating tests
1602 mundus:~/MyApp chansen$ cat t/01app.t | perl -ne 'printf( "%2d %s", $., $_ )'
1603 1 use Test::More tests => 2;
1604 2 use_ok( Catalyst::Test, 'MyApp' );
1606 4 ok( request('/')->is_success );
1608 The first line declares how many tests we are going to run, in this case
1609 two. The second line tests and loads our application in test mode. The
1610 fourth line verifies that our application returns a successful response.
1612 C<Catalyst::Test> exports two functions, C<request> and C<get>. Each can
1613 take three different arguments:
1617 =item A string which is a relative or absolute URI.
1619 request('/my/path');
1620 request('http://www.host.com/my/path');
1622 =item An instance of C<URI>.
1624 request( URI->new('http://www.host.com/my/path') );
1626 =item An instance of C<HTTP::Request>.
1628 request( HTTP::Request->new( GET => 'http://www.host.com/my/path') );
1632 C<request> returns an instance of C<HTTP::Response> and C<get> returns the
1633 content (body) of the response.
1635 =head3 Running tests locally
1637 mundus:~/MyApp chansen$ CATALYST_DEBUG=0 TEST_POD=1 prove --lib lib/ t/
1638 t/01app............ok
1639 t/02pod............ok
1640 t/03podcoverage....ok
1641 All tests successful.
1642 Files=3, Tests=4, 2 wallclock secs ( 1.60 cusr + 0.36 csys = 1.96 CPU)
1644 C<CATALYST_DEBUG=0> ensures that debugging is off; if it's enabled you
1645 will see debug logs between tests.
1647 C<TEST_POD=1> enables POD checking and coverage.
1649 C<prove> A command-line tool that makes it easy to run tests. You can
1650 find out more about it from the links below.
1652 =head3 Running tests remotely
1654 mundus:~/MyApp chansen$ CATALYST_SERVER=http://localhost:3000/ prove --lib lib/ t/01app.t
1656 All tests successful.
1657 Files=1, Tests=2, 0 wallclock secs ( 0.40 cusr + 0.01 csys = 0.41 CPU)
1659 C<CATALYST_SERVER=http://localhost:3000/> is the absolute deployment URI of
1660 your application. In C<CGI> or C<FastCGI> it should be the host and path
1663 =head3 C<Test::WWW::Mechanize> and Catalyst
1665 Be sure to check out C<Test::WWW::Mechanize::Catalyst>. It makes it easy to
1666 test HTML, forms and links. A short example of usage:
1668 use Test::More tests => 6;
1669 use_ok( Test::WWW::Mechanize::Catalyst, 'MyApp' );
1671 my $mech = Test::WWW::Mechanize::Catalyst->new;
1672 $mech->get_ok("http://localhost/", 'Got index page');
1673 $mech->title_like( qr/^MyApp on Catalyst/, 'Got right index title' );
1674 ok( $mech->find_link( text_regex => qr/^Wiki/i ), 'Found link to Wiki' );
1675 ok( $mech->find_link( text_regex => qr/^Mailing-List/i ), 'Found link to Mailing-List' );
1676 ok( $mech->find_link( text_regex => qr/^IRC channel/i ), 'Found link to IRC channel' );
1678 =head3 Further Reading
1682 =item Catalyst::Test
1684 L<http://search.cpan.org/dist/Catalyst/lib/Catalyst/Test.pm>
1686 =item Test::WWW::Mechanize::Catalyst
1688 L<http://search.cpan.org/dist/Test-WWW-Mechanize-Catalyst/lib/Test/WWW/Mechanize/Catalyst.pm>
1690 =item Test::WWW::Mechanize
1692 L<http://search.cpan.org/dist/Test-WWW-Mechanize/Mechanize.pm>
1694 =item WWW::Mechanize
1696 L<http://search.cpan.org/dist/WWW-Mechanize/lib/WWW/Mechanize.pm>
1698 =item LWP::UserAgent
1700 L<http://search.cpan.org/dist/libwww-perl/lib/LWP/UserAgent.pm>
1704 L<http://search.cpan.org/dist/libwww-perl/lib/HTML/Form.pm>
1708 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Message.pm>
1712 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request.pm>
1714 =item HTTP::Request::Common
1716 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request/Common.pm>
1718 =item HTTP::Response
1720 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Response.pm>
1724 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Status.pm>
1728 L<http://search.cpan.org/dist/URI/URI.pm>
1732 L<http://search.cpan.org/dist/Test-Simple/lib/Test/More.pm>
1736 L<http://search.cpan.org/dist/Test-Pod/Pod.pm>
1738 =item Test::Pod::Coverage
1740 L<http://search.cpan.org/dist/Test-Pod-Coverage/Coverage.pm>
1742 =item prove (Test::Harness)
1744 L<http://search.cpan.org/dist/Test-Harness/bin/prove>
1750 Unlike SOAP, XMLRPC is a very simple (and imo elegant) web-services
1751 protocol, exchanging small XML messages like these:
1756 TE: deflate,gzip;q=0.3
1757 Connection: TE, close
1760 Host: 127.0.0.1:3000
1761 User-Agent: SOAP::Lite/Perl/0.60
1763 Content-Type: text/xml
1765 <?xml version="1.0" encoding="UTF-8"?>
1767 <methodName>add</methodName>
1769 <param><value><int>1</int></value></param>
1770 <param><value><int>2</int></value></param>
1777 Date: Tue, 20 Dec 2005 07:45:55 GMT
1779 Content-Type: text/xml
1783 <?xml version="1.0" encoding="us-ascii"?>
1786 <param><value><int>3</int></value></param>
1790 Now follow these few steps to implement the application:
1792 1. Install Catalyst (5.61 or later), Catalyst::Plugin::XMLRPC (0.06 or
1793 later) and SOAP::Lite (for XMLRPCsh.pl).
1795 2. Create an application framework:
1801 3. Add the XMLRPC plugin to MyApp.pm
1803 use Catalyst qw/-Debug Static::Simple XMLRPC/;
1805 4. Add an API controller
1807 % ./script/myapp_create.pl controller API
1809 5. Add a XMLRPC redispatch method and an add method with Remote
1810 attribute to lib/MyApp/Controller/API.pm
1812 sub default : Private {
1813 my ( $self, $c ) = @_;
1818 my ( $self, $c, $a, $b ) = @_;
1822 The default action is the entry point for each XMLRPC request. It will
1823 redispatch every request to methods with Remote attribute in the same
1826 The C<add> method is not a traditional action; it has no private or
1827 public path. Only the XMLRPC dispatcher knows it exists.
1829 6. That's it! You have built your first web service. Let's test it with
1830 XMLRPCsh.pl (part of SOAP::Lite):
1832 % ./script/myapp_server.pl
1834 % XMLRPCsh.pl http://127.0.0.1:3000/api
1835 Usage: method[(parameters)]
1837 --- XMLRPC RESULT ---
1842 Your return data type is usually auto-detected, but you can easily
1843 enforce a specific one.
1846 my ( $self, $c, $a, $b ) = @_;
1847 return RPC::XML::int->new( $a + $b );
1854 A Catalyst application is driven by one or more Controller modules. There are
1855 a number of ways that Catalyst can decide which of the methods in your
1856 controller modules it should call. Controller methods are also called actions,
1857 because they determine how your catalyst application should (re-)act to any
1858 given URL. When the application is started up, catalyst looks at all your
1859 actions, and decides which URLs they map to.
1861 =head3 Type attributes
1863 Each action is a normal method in your controller, except that it has an
1864 L<attribute|http://search.cpan.org/~nwclark/perl-5.8.7/lib/attributes.pm>
1865 attached. These can be one of several types.
1867 Assume our Controller module starts with the following package declaration:
1869 package MyApp::Controller::Buckets;
1871 and we are running our application on localhost, port 3000 (the test
1878 A Path attribute also takes an argument, this can be either a relative
1879 or an absolute path. A relative path will be relative to the controller
1880 namespace, an absolute path will represent an exact matching URL.
1882 sub my_handles : Path('handles') { .. }
1886 http://localhost:3000/buckets/handles
1890 sub my_handles : Path('/handles') { .. }
1894 http://localhost:3000/handles
1898 When using a Local attribute, no parameters are needed, instead, the name of
1899 the action is matched in the URL. The namespaces created by the name of the
1900 controller package is always part of the URL.
1902 sub my_handles : Local { .. }
1906 http://localhost:3000/buckets/my_handles
1910 A Global attribute is similar to a Local attribute, except that the namespace
1911 of the controller is ignored, and matching starts at root.
1913 sub my_handles : Global { .. }
1917 http://localhost:3000/my_handles
1921 By now you should have figured that a Regex attribute is just what it sounds
1922 like. This one takes a regular expression, and matches starting from
1923 root. These differ from the rest as they can match multiple URLs.
1925 sub my_handles : Regex('^handles') { .. }
1929 http://localhost:3000/handles
1933 http://localhost:3000/handles_and_other_parts
1939 A LocalRegex is similar to a Regex, except it only matches below the current
1940 controller namespace.
1942 sub my_handles : LocalRegex(^handles') { .. }
1946 http://localhost:3000/buckets/handles
1950 http://localhost:3000/buckets/handles_and_other_parts
1956 Last but not least, there is the Private attribute, which allows you to create
1957 your own internal actions, which can be forwarded to, but won't be matched as
1960 sub my_handles : Private { .. }
1962 becomes nothing at all..
1964 Catalyst also predefines some special Private actions, which you can override,
1971 The default action will be called, if no other matching action is found. If
1972 you don't have one of these in your namespace, or any sub part of your
1973 namespace, you'll get an error page instead. If you want to find out where it
1974 was the user was trying to go, you can look in the request object using
1975 C<< $c->req->path >>.
1977 sub default : Private { .. }
1979 works for all unknown URLs, in this controller namespace, or every one if put
1980 directly into MyApp.pm.
1984 The index action is called when someone tries to visit the exact namespace of
1985 your controller. If index, default and matching Path actions are defined, then
1986 index will be used instead of default and Path.
1988 sub index : Private { .. }
1992 http://localhost:3000/buckets
1996 The begin action is called at the beginning of every request involving this
1997 namespace directly, before other matching actions are called. It can be used
1998 to set up variables/data for this particular part of your app. A single begin
1999 action is called, its always the one most relevant to the current namespace.
2001 sub begin : Private { .. }
2005 http://localhost:3000/bucket/(anything)?
2011 Like begin, this action is always called for the namespace it is in, after
2012 every other action has finished. It is commonly used to forward processing to
2013 the View component. A single end action is called, its always the one most
2014 relevant to the current namespace.
2017 sub end : Private { .. }
2019 is called once after any actions when
2021 http://localhost:3000/bucket/(anything)?
2027 Lastly, the auto action is magic in that B<every> auto action in
2028 the chain of paths up to and including the ending namespace, will be
2029 called. (In contrast, only one of the begin/end/default actions will be
2030 called, the relevant one).
2033 sub auto : Private { .. }
2037 sub auto : Private { .. }
2039 will both be called when visiting
2041 http://localhost:3000/bucket/(anything)?
2047 =head3 A word of warning
2049 Due to possible namespace conflicts with Plugins, it is advised to only put the
2050 pre-defined Private actions in your main MyApp.pm file, all others should go
2051 in a Controller module.
2053 =head3 More Information
2055 L<http://search.cpan.org/author/SRI/Catalyst-5.61/lib/Catalyst/Manual/Intro.pod>
2057 L<http://dev.catalyst.perl.org/wiki/FlowChart>
2060 =head2 Authorization
2064 Authorization is the step that comes after authentication. Authentication
2065 establishes that the user agent is really representing the user we think it's
2066 representing, and then authorization determines what this user is allowed to
2069 =head3 Role Based Access Control
2071 Under role based access control each user is allowed to perform any number of
2072 roles. For example, at a zoo no one but specially trained personnel can enter
2073 the moose cage (Mynd you, møøse bites kan be pretty nasti!). For example:
2075 package Zoo::Controller::MooseCage;
2077 sub feed_moose : Local {
2078 my ( $self, $c ) = @_;
2080 $c->model( "Moose" )->eat( $c->req->param("food") );
2083 With this action, anyone can just come into the moose cage and feed the moose,
2084 which is a very dangerous thing. We need to restrict this action, so that only
2085 a qualified moose feeder can perform that action.
2087 The Authorization::Roles plugin let's us perform role based access control
2088 checks. Let's load it:
2091 Authentication # yadda yadda
2092 Authorization::Roles
2095 And now our action should look like this:
2097 sub feed_moose : Local {
2098 my ( $self, $c ) = @_;
2100 if ( $c->check_roles( "moose_feeder" ) ) {
2101 $c->model( "Moose" )->eat( $c->req->param("food") );
2103 $c->stash->{error} = "unauthorized";
2107 This checks C<< $c->user >>, and only if the user has B<all> the roles in the
2108 list, a true value is returned.
2110 C<check_roles> has a sister method, C<assert_roles>, which throws an exception
2111 if any roles are missing.
2113 Some roles that might actually make sense in, say, a forum application:
2127 each with a distinct task (system administration versus content administration).
2129 =head3 Access Control Lists
2131 Checking for roles all the time can be tedious and error prone.
2133 The Authorization::ACL plugin let's us declare where we'd like checks to be
2134 done automatically for us.
2136 For example, we may want to completely block out anyone who isn't a
2137 C<moose_feeder> from the entire C<MooseCage> controller:
2139 Zoo->deny_access_unless( "/moose_cage", [qw/moose_feeder/] );
2141 The role list behaves in the same way as C<check_roles>. However, the ACL
2142 plugin isn't limited to just interacting with the Roles plugin. We can use a
2143 code reference instead. For example, to allow either moose trainers or moose
2144 feeders into the moose cage, we can create a more complex check:
2146 Zoo->deny_access_unless( "/moose_cage", sub {
2148 $c->check_roles( "moose_trainer" ) || $c->check_roles( "moose_feeder" );
2151 The more specific a role, the earlier it will be checked. Let's say moose
2152 feeders are now restricted to only the C<feed_moose> action, while moose
2153 trainers get access everywhere:
2155 Zoo->deny_access_unless( "/moose_cage", [qw/moose_trainer/] );
2156 Zoo->allow_access_if( "/moose_cage/feed_moose", [qw/moose_feeder/]);
2158 When the C<feed_moose> action is accessed the second check will be made. If the
2159 user is a C<moose_feeder>, then access will be immediately granted. Otherwise,
2160 the next rule in line will be tested - the one checking for a C<moose_trainer>.
2161 If this rule is not satisfied, access will be immediately denied.
2163 Rules applied to the same path will be checked in the order they were added.
2165 Lastly, handling access denial events is done by creating an C<access_denied>
2168 sub access_denied : Private {
2169 my ( $self, $c, $action ) = @_;
2174 This action works much like auto, in that it is inherited across namespaces
2175 (not like object oriented code). This means that the C<access_denied> action
2176 which is B<nearest> to the action which was blocked will be triggered.
2178 If this action does not exist, an error will be thrown, which you can clean up
2179 in your C<end> private action instead.
2181 Also, it's important to note that if you restrict access to "/" then C<end>,
2182 C<default>, etc will also be restricted.
2184 MyApp->acl_allow_root_internals;
2186 will create rules that permit access to C<end>, C<begin>, and C<auto> in the
2187 root of your app (but not in any other controller).
2189 =head3 More Information
2191 L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authorization::Roles>
2192 L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authorization::ACL>
2196 Sebastian Riedel, C<sri@oook.de>
2197 Danijel Milicevic, C<me@danijel.de>
2198 Viljo Marrandi, C<vilts@yahoo.com>
2199 Marcus Ramberg, C<mramberg@cpan.org>
2200 Jesse Sheidlower, C<jester@panix.com>
2201 Andy Grundman, C<andy@hybridized.org>
2202 Chisel Wright, C<pause@herlpacker.co.uk>
2203 Will Hawes, C<info@whawes.co.uk>
2204 Gavin Henry, C<ghenry@perl.me.uk>
2209 This program is free software, you can redistribute it and/or modify it
2210 under the same terms as Perl itself.