3 Catalyst::Manual::Cookbook - Cooking with Catalyst
7 Yummy code like your mum used to bake!
13 These recipes cover some basic stuff that is worth knowing for
16 =head2 Delivering a Custom Error Page
18 By default, Catalyst will display its own error page whenever it
19 encounters an error in your application. When running under C<-Debug>
20 mode, the error page is a useful screen including the error message
21 and L<Data::Dump> output of the relevant parts of the C<$c> context
22 object. When not in C<-Debug>, users see a simple "Please come back
25 To use a custom error page, use a special C<end> method to
26 short-circuit the error processing. The following is an example; you
27 might want to adjust it further depending on the needs of your
28 application (for example, any calls to C<fillform> will probably need
29 to go into this C<end> method; see L<Catalyst::Plugin::FillInForm>).
32 my ( $self, $c ) = @_;
34 if ( scalar @{ $c->error } ) {
35 $c->stash->{errors} = $c->error;
36 $c->stash->{template} = 'errors.tt';
37 $c->forward('MyApp::View::TT');
41 return 1 if $c->response->status =~ /^3\d\d$/;
42 return 1 if $c->response->body;
44 unless ( $c->response->content_type ) {
45 $c->response->content_type('text/html; charset=utf-8');
48 $c->forward('MyApp::View::TT');
51 You can manually set errors in your code to trigger this page by calling
53 $c->error( 'You broke me!' );
55 =head2 Disable statistics
57 Just add this line to your application class if you don't want those
58 nifty statistics in your debug messages.
60 sub Catalyst::Log::info { }
62 =head2 Enable debug status in the environment
64 Normally you enable the debugging info by adding the C<-Debug> flag to
65 your C<use Catalyst> statement . However, you can also enable it using
66 environment variable, so you can (for example) get debug info without
67 modifying your application scripts. Just set C<CATALYST_DEBUG> or
68 C<E<lt>MYAPPE<gt>_DEBUG> to a true value.
72 When you have your users identified, you will want to somehow remember
73 that fact, to save them from having to identify themselves for every
74 single page. One way to do this is to send the username and password
75 parameters in every single page, but that's ugly, and won't work for
78 Sessions are a method of saving data related to some transaction, and
79 giving the whole collection a single ID. This ID is then given to the
80 user to return to us on every page they visit while logged in. The
81 usual way to do this is using a browser cookie.
83 Catalyst uses two types of plugins to represent sessions:
87 A State module is used to keep track of the state of the session
88 between the users browser, and your application.
90 A common example is the Cookie state module, which sends the browser a
91 cookie containing the session ID. It will use default value for the
92 cookie name and domain, so will "just work" when used.
96 A Store module is used to hold all the data relating to your session,
97 for example the users ID, or the items for their shopping cart. You
98 can store data in memory (FastMmap), in a file (File) or in a database
101 =head3 Authentication magic
103 If you have included the session modules in your application, the
104 Authentication modules will automagically use your session to save and
105 retrieve the user data for you.
107 =head3 Using a session
109 Once the session modules are loaded, the session is available as C<<
110 $c->session >>, and can be writen to and read from as a simple hash
117 use namespace::autoclean;
121 Session::Store::FastMmap
122 Session::State::Cookie
127 package MyApp::Controller::Foo;
129 use namespace::autoclean;
130 BEGIN { extends 'Catalyst::Controller';
131 ## Write data into the session
133 sub add_item : Local {
134 my ( $self, $c ) = @_;
136 my $item_id = $c->req->param("item");
138 push @{ $c->session->{items} }, $item_id;
142 ## A page later we retrieve the data from the session:
144 sub get_items : Local {
145 my ( $self, $c ) = @_;
147 $c->stash->{items_to_display} = $c->session->{items};
152 =head3 More information
154 L<http://search.cpan.org/dist/Catalyst-Plugin-Session>
156 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-Cookie>
158 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-URI>
160 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-FastMmap>
162 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-File>
164 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-DBI>
166 =head2 Configure your application
168 You configure your application with the C<config> method in your
169 application class. This can be hard-coded, or brought in from a
170 separate configuration file.
172 =head3 Using Config::General
174 L<Config::General|Config::General> is a method for creating flexible
175 and readable configuration files. It's a great way to keep your
176 Catalyst application configuration in one easy-to-understand location.
178 Now create C<myapp.conf> in your application home:
182 # session; perldoc Catalyst::Plugin::Session::FastMmap
186 storage /tmp/myapp.session
189 # emails; perldoc Catalyst::Plugin::Email
190 # this passes options as an array :(
194 This is equivalent to:
196 # configure base package
197 __PACKAGE__->config( name => MyApp );
198 # configure authentication
199 __PACKAGE__->config->{authentication} = {
200 user_class => 'MyApp::Model::MyDB::Customer',
204 __PACKAGE__->config->{session} = {
208 # configure email sending
209 __PACKAGE__->config->{email} = [qw/SMTP localhost/];
211 See also L<Config::General|Config::General>.
213 =head1 Skipping your VCS's directories
215 Catalyst uses Module::Pluggable to load Models, Views and Controllers.
216 Module::Pluggable will scan through all directories and load modules
217 it finds. Sometimes you might want to skip some of these directories,
218 for example when your version control system makes a subdirectory with
219 meta-information in every version-controlled directory. While
220 Catalyst skips subversion and CVS directories already, there are other
221 source control systems. Here is the configuration you need to add
222 their directories to the list to skip.
224 You can make catalyst skip these directories using the Catalyst config:
226 # Configure the application
229 setup_components => { except => qr/SCCS/ },
232 See the Module::Pluggable manual page for more information on B<except>
235 =head1 Users and Access Control
237 Most multiuser, and some single user web applications require that
238 users identify themselves, and the application is often required to
239 define those roles. The recipes below describe some ways of doing
242 =head2 Authentication (logging in)
244 This is extensively covered in other documentation; see in particular
245 L<Catalyst::Plugin::Authentication> and the Authentication chapter
246 of the Tutorial at L<Catalyst::Manual::Tutorial::Authorization>.
248 =head2 Pass-through login (and other actions)
250 An easy way of having assorted actions that occur during the processing
251 of a request that are orthogonal to its actual purpose - logins, silent
252 commands etc. Provide actions for these, but when they're required for
253 something else fill e.g. a form variable __login and have a sub begin
256 sub begin : Private {
258 foreach my $action (qw/login docommand foo bar whatever/) {
259 if ($c->req->params->{"__${action}"}) {
260 $c->forward($action);
265 =head2 Authentication/Authorization
267 This is done in several steps:
273 Getting the user to identify themselves, by giving you some piece of
274 information known only to you and the user. Then you can assume that
275 the user is who they say they are. This is called B<credential
280 Making sure the user only accesses functions you want them to
281 access. This is done by checking the verified users data against your
282 internal list of groups, or allowed persons for the current page.
288 The Catalyst Authentication system is made up of many interacting
289 modules, to give you the most flexibility possible.
291 =head4 Credential verifiers
293 A Credential module tables the user input, and passes it to a Store,
294 or some other system, for verification. Typically, a user object is
295 created by either this module or the Store and made accessible by a
296 C<< $c->user >> call.
300 Password - Simple username/password checking.
301 HTTPD - Checks using basic HTTP auth.
302 TypeKey - Check using the typekey system.
304 =head3 Storage backends
306 A Storage backend contains the actual data representing the users. It
307 is queried by the credential verifiers. Updating the store is not done
308 within this system, you will need to do it yourself.
312 DBIC - Storage using a database.
313 Minimal - Storage using a simple hash (for testing).
317 A User object is created by either the storage backend or the
318 credential verifier, and filled with the retrieved user information.
322 Hash - A simple hash of keys and values.
324 =head3 ACL authorization
326 ACL stands for Access Control List. The ACL plugin allows you to
327 regulate access on a path by path basis, by listing which users, or
328 roles, have access to which paths.
330 =head3 Roles authorization
332 Authorization by roles is for assigning users to groups, which can
333 then be assigned to ACLs, or just checked when needed.
337 When you have chosen your modules, all you need to do is call the C<<
338 $c->authenticate >> method. If called with no parameters, it will try to find
339 suitable parameters, such as B<username> and B<password>, or you can
340 pass it these values.
342 =head3 Checking roles
344 Role checking is done by using the C<< $c->check_user_roles >> method,
345 this will check using the currently logged in user (via C<< $c->user
346 >>). You pass it the name of a role to check, and it returns true if
347 the user is a member.
353 use namespace::autoclean;
354 extends qw/Catalyst/;
362 default_realm => 'test',
367 password_field => 'password',
368 password_type => 'self_check',
379 package MyApp::Controller::Root;
381 use namespace::autoclean;
383 BEGIN { extends 'Catalyst::Controller' }
385 __PACKAGE__->config(namespace => '');
390 if ( my $user = $c->req->param("user")
391 and my $password = $c->req->param("password") )
393 if ( $c->authenticate( username => $user, password => $password ) ) {
394 $c->res->body( "hello " . $c->user->name );
404 sub restricted : Local {
405 my ( $self, $c ) = @_;
407 $c->detach("unauthorized")
408 unless $c->check_user_roles( "admin" );
410 # do something restricted here
413 =head3 Using authentication in a testing environment
415 Ideally, to write tests for authentication/authorization code one
416 would first set up a test database with known data, then use
417 L<Test::WWW::Mechanize::Catalyst> to simulate a user logging
418 in. Unfortunately the former can be rather awkward, which is why it's
419 a good thing that the authentication framework is so flexible.
421 Instead of using a test database, one can simply change the
422 authentication store to something a bit easier to deal with in a
423 testing environment. Additionally, this has the advantage of not
424 modifying one's database, which can be problematic if one forgets to
425 use the testing instead of production database.
427 Alternatively, if you want to authenticate real users, but not have to worry about
428 their passwords, you can use L<Catalyst::Authentication::Credential::Testing>
429 to force all users to authenticate with a global password.
431 =head3 More information
433 L<Catalyst::Plugin::Authentication> has a longer explanation.
439 Authorization is the step that comes after
440 authentication. Authentication establishes that the user agent is
441 really representing the user we think it's representing, and then
442 authorization determines what this user is allowed to do.
444 =head3 Role Based Access Control
446 Under role based access control each user is allowed to perform any
447 number of roles. For example, at a zoo no one but specially trained
448 personnel can enter the moose cage (Mynd you, møøse bites kan be
449 pretty nasti!). For example:
451 package Zoo::Controller::MooseCage;
453 sub feed_moose : Local {
454 my ( $self, $c ) = @_;
456 $c->model( "Moose" )->eat( $c->req->param("food") );
459 With this action, anyone can just come into the moose cage and feed
460 the moose, which is a very dangerous thing. We need to restrict this
461 action, so that only a qualified moose feeder can perform that action.
463 The Authorization::Roles plugin let's us perform role based access
464 control checks. Let's load it:
466 use parent qw/Catalyst/;
472 And now our action should look like this:
474 sub feed_moose : Local {
475 my ( $self, $c ) = @_;
477 if ( $c->check_roles( "moose_feeder" ) ) {
478 $c->model( "Moose" )->eat( $c->req->param("food") );
480 $c->stash->{error} = "unauthorized";
484 This checks C<< $c->user >>, and only if the user has B<all> the roles
485 in the list, a true value is returned.
487 C<check_roles> has a sister method, C<assert_roles>, which throws an
488 exception if any roles are missing.
490 Some roles that might actually make sense in, say, a forum application:
504 each with a distinct task (system administration versus content
507 =head3 Access Control Lists
509 Checking for roles all the time can be tedious and error prone.
511 The Authorization::ACL plugin let's us declare where we'd like checks
512 to be done automatically for us.
514 For example, we may want to completely block out anyone who isn't a
515 C<moose_feeder> from the entire C<MooseCage> controller:
517 Zoo->deny_access_unless( "/moose_cage", [qw/moose_feeder/] );
519 The role list behaves in the same way as C<check_roles>. However, the
520 ACL plugin isn't limited to just interacting with the Roles plugin. We
521 can use a code reference instead. For example, to allow either moose
522 trainers or moose feeders into the moose cage, we can create a more
525 Zoo->deny_access_unless( "/moose_cage", sub {
527 $c->check_roles( "moose_trainer" ) || $c->check_roles( "moose_feeder" );
530 The more specific a role, the earlier it will be checked. Let's say
531 moose feeders are now restricted to only the C<feed_moose> action,
532 while moose trainers get access everywhere:
534 Zoo->deny_access_unless( "/moose_cage", [qw/moose_trainer/] );
535 Zoo->allow_access_if( "/moose_cage/feed_moose", [qw/moose_feeder/]);
537 When the C<feed_moose> action is accessed the second check will be
538 made. If the user is a C<moose_feeder>, then access will be
539 immediately granted. Otherwise, the next rule in line will be tested -
540 the one checking for a C<moose_trainer>. If this rule is not
541 satisfied, access will be immediately denied.
543 Rules applied to the same path will be checked in the order they were
546 Lastly, handling access denial events is done by creating an
547 C<access_denied> private action:
549 sub access_denied : Private {
550 my ( $self, $c, $action ) = @_;
553 This action works much like auto, in that it is inherited across
554 namespaces (not like object oriented code). This means that the
555 C<access_denied> action which is B<nearest> to the action which was
556 blocked will be triggered.
558 If this action does not exist, an error will be thrown, which you can
559 clean up in your C<end> private action instead.
561 Also, it's important to note that if you restrict access to "/" then
562 C<end>, C<default>, etc will also be restricted.
564 MyApp->acl_allow_root_internals;
566 will create rules that permit access to C<end>, C<begin>, and C<auto> in the
567 root of your app (but not in any other controller).
571 Models are where application data belongs. Catalyst is exteremely
572 flexible with the kind of models that it can use. The recipes here
575 =head2 Using existing DBIC (etc.) classes with Catalyst
577 Many people have existing Model classes that they would like to use
578 with Catalyst (or, conversely, they want to write Catalyst models that
579 can be used outside of Catalyst, e.g. in a cron job). It's trivial to
580 write a simple component in Catalyst that slurps in an outside Model:
582 package MyApp::Model::DB;
583 use base qw/Catalyst::Model::DBIC::Schema/;
585 schema_class => 'Some::DBIC::Schema',
586 connect_info => ['dbi:SQLite:foo.db', '', '', {AutoCommit=>1}];
590 and that's it! Now C<Some::DBIC::Schema> is part of your
591 Cat app as C<MyApp::Model::DB>.
593 =head2 DBIx::Class as a Catalyst Model
595 See L<Catalyst::Model::DBIC::Schema>.
597 =head2 Create accessors to preload static data once per server instance
599 When you have data that you want to load just once from the model at
600 server load instead of for each request, use mk_group_accessors to
601 create accessors and tie them to resultsets in your package that
602 inherits from DBIx::Class::Schema
605 use base qw/DBIx::Class::Schema/;
606 __PACKAGE__->register_class('RESULTSOURCEMONIKER',
607 'My::Schema::RESULTSOURCE');
608 __PACKAGE__->mk_group_accessors('simple' =>
609 qw(ACCESSORNAME1 ACCESSORNAME2 ACCESSORNAMEn));
612 my ($self, @rest) = @_;
613 $self->next::method(@rest);
614 # $self is now a live My::Schema object, complete with DB connection
616 $self->ACCESSORNAME1([ $self->resultset('RESULTSOURCEMONIKER')->all ]);
617 $self->ACCESSORNAME2([ $self->resultset('RESULTSOURCEMONIKER')->search({ COLUMN => { '<' => '30' } })->all ]);
618 $self->ACCESSORNAMEn([ $self->resultset('RESULTSOURCEMONIKER')->find(1) ]);
623 and now in the controller, you can now access any of these without a
626 $c->stash->{something} = $c->model('My::Schema')->schema->ACCESSORNAMEn;
631 Unlike SOAP, XMLRPC is a very simple (and imo elegant) web-services
632 protocol, exchanging small XML messages like these:
637 TE: deflate,gzip;q=0.3
638 Connection: TE, close
642 User-Agent: SOAP::Lite/Perl/0.60
644 Content-Type: text/xml
646 <?xml version="1.0" encoding="UTF-8"?>
648 <methodName>add</methodName>
650 <param><value><int>1</int></value></param>
651 <param><value><int>2</int></value></param>
658 Date: Tue, 20 Dec 2005 07:45:55 GMT
660 Content-Type: text/xml
664 <?xml version="1.0" encoding="us-ascii"?>
667 <param><value><int>3</int></value></param>
671 Now follow these few steps to implement the application:
673 1. Install Catalyst (5.61 or later), Catalyst::Plugin::XMLRPC (0.06 or
674 later) and SOAP::Lite (for XMLRPCsh.pl).
676 2. Create an application framework:
682 3. Add the XMLRPC plugin to MyApp.pm
684 use Catalyst qw/-Debug Static::Simple XMLRPC/;
686 4. Add an API controller
688 % ./script/myapp_create.pl controller API
690 5. Add a XMLRPC redispatch method and an add method with Remote
691 attribute to lib/MyApp/Controller/API.pm
694 my ( $self, $c ) = @_;
699 my ( $self, $c, $a, $b ) = @_;
703 The default action is the entry point for each XMLRPC request. It will
704 redispatch every request to methods with Remote attribute in the same
707 The C<add> method is not a traditional action; it has no private or
708 public path. Only the XMLRPC dispatcher knows it exists.
710 6. That's it! You have built your first web service. Let's test it with
711 XMLRPCsh.pl (part of SOAP::Lite):
713 % ./script/myapp_server.pl
715 % XMLRPCsh.pl http://127.0.0.1:3000/api
716 Usage: method[(parameters)]
718 --- XMLRPC RESULT ---
723 Your return data type is usually auto-detected, but you can easily
724 enforce a specific one.
727 my ( $self, $c, $a, $b ) = @_;
728 return RPC::XML::int->new( $a + $b );
733 Views pertain to the display of your application. As with models,
734 catalyst is uncommonly flexible. The recipes below are just a start.
736 =head2 Catalyst::View::TT
738 One of the first things you probably want to do when starting a new
739 Catalyst application is set up your View. Catalyst doesn't care how you
740 display your data; you can choose to generate HTML, PDF files, or plain
743 Most Catalyst applications use a template system to generate their HTML,
744 and though there are several template systems available, Template
745 Toolkit is probably the most popular.
747 Once again, the Catalyst developers have done all the hard work, and
748 made things easy for the rest of us. Catalyst::View::TT provides the
749 interface to Template Toolkit, and provides Helpers which let us set it
750 up that much more easily.
752 =head3 Creating your View
754 Catalyst::View::TT provides two different helpers for us to use: TT and
759 Create a basic Template Toolkit View using the provided helper script:
761 script/myapp_create.pl view TT TT
763 This will create lib/MyApp/View/MyView.pm, which is going to be pretty
764 empty to start. However, it sets everything up that you need to get
765 started. You can now define which template you want and forward to your
769 my ( $self, $c ) = @_;
771 $c->stash->{template} = 'hello.tt';
773 $c->forward( $c->view('TT') );
776 In practice you wouldn't do the forwarding manually, but would
777 use L<Catalyst::Action::RenderView>.
781 Although the TT helper does create a functional, working view, you may
782 find yourself having to create the same template files and changing the
783 same options every time you create a new application. The TTSite helper
784 saves us even more time by creating the basic templates and setting some
785 common options for us.
787 Once again, you can use the helper script:
789 script/myapp_create.pl view TT TTSite
791 This time, the helper sets several options for us in the generated View.
793 __PACKAGE__->config({
794 CATALYST_VAR => 'Catalyst',
796 MyApp->path_to( 'root', 'src' ),
797 MyApp->path_to( 'root', 'lib' )
799 PRE_PROCESS => 'config/main',
800 WRAPPER => 'site/wrapper',
801 ERROR => 'error.tt2',
809 INCLUDE_PATH defines the directories that Template Toolkit should search
810 for the template files.
814 PRE_PROCESS is used to process configuration options which are common to
819 WRAPPER is a file which is processed with each template, usually used to
820 easily provide a common header and footer for every page.
824 In addition to setting these options, the TTSite helper also created the
825 template and config files for us! In the 'root' directory, you'll notice
826 two new directories: src and lib.
828 Several configuration files in root/lib/config are called by PRE_PROCESS.
830 The files in root/lib/site are the site-wide templates, called by
831 WRAPPER, and display the html framework, control the layout, and provide
832 the templates for the header and footer of your page. Using the template
833 organization provided makes it much easier to standardize pages and make
834 changes when they are (inevitably) needed.
836 The template files that you will create for your application will go
837 into root/src, and you don't need to worry about putting the the <html>
838 or <head> sections; just put in the content. The WRAPPER will the rest
839 of the page around your template for you.
844 Of course, having the template system include the header and footer for
845 you isn't all that we want our templates to do. We need to be able to
846 put data into our templates, and have it appear where and how we want
847 it, right? That's where the stash comes in.
849 In our controllers, we can add data to the stash, and then access it
850 from the template. For instance:
853 my ( $self, $c ) = @_;
855 $c->stash->{name} = 'Adam';
857 $c->stash->{template} = 'hello.tt';
859 $c->forward( $c->view('TT') );
864 <strong>Hello, [% name %]!</strong>
866 When you view this page, it will display "Hello, Adam!"
868 All of the information in your stash is available, by its name/key, in
869 your templates. And your data don't have to be plain, old, boring
870 scalars. You can pass array references and hash references, too.
875 my ( $self, $c ) = @_;
877 $c->stash->{names} = [ 'Adam', 'Dave', 'John' ];
879 $c->stash->{template} = 'hello.tt';
881 $c->forward( $c->view('TT') );
886 [% FOREACH name IN names %]
887 <strong>Hello, [% name %]!</strong><br />
890 This allowed us to loop through each item in the arrayref, and display a
891 line for each name that we have.
893 This is the most basic usage, but Template Toolkit is quite powerful,
894 and allows you to truly keep your presentation logic separate from the
895 rest of your application.
899 One of my favorite things about Catalyst is the ability to move an
900 application around without having to worry that everything is going to
901 break. One of the areas that used to be a problem was with the http
902 links in your template files. For example, suppose you have an
903 application installed at http://www.domain.com/Calendar. The links point
904 to "/Calendar", "/Calendar/2005", "/Calendar/2005/10", etc. If you move
905 the application to be at http://www.mydomain.com/Tools/Calendar, then
906 all of those links will suddenly break.
908 That's where $c->uri_for() comes in. This function will merge its
909 parameters with either the base location for the app, or its current
910 namespace. Let's take a look at a couple of examples.
912 In your template, you can use the following:
914 <a href="[% c.uri_for('/login') %]">Login Here</a>
916 Although the parameter starts with a forward slash, this is relative
917 to the application root, not the webserver root. This is important to
918 remember. So, if your application is installed at
919 http://www.domain.com/Calendar, then the link would be
920 http://www.mydomain.com/Calendar/Login. If you move your application
921 to a different domain or path, then that link will still be correct.
925 <a href="[% c.uri_for('2005','10', '24') %]">October, 24 2005</a>
927 The first parameter does NOT have a forward slash, and so it will be
928 relative to the current namespace. If the application is installed at
929 http://www.domain.com/Calendar. and if the template is called from
930 MyApp::Controller::Display, then the link would become
931 http://www.domain.com/Calendar/Display/2005/10/24.
933 If you want to link to a parent uri of your current namespace you can
934 prefix the arguments with multiple '../':
936 <a href="[% c.uri_for('../../view', stashed_object.id) %]">User view</a>
938 Once again, this allows you to move your application around without
939 having to worry about broken links. But there's something else, as
940 well. Since the links are generated by uri_for, you can use the same
941 template file by several different controllers, and each controller
942 will get the links that its supposed to. Since we believe in Don't
943 Repeat Yourself, this is particularly helpful if you have common
944 elements in your site that you want to keep in one file.
948 L<http://search.cpan.org/perldoc?Catalyst>
950 L<http://search.cpan.org/perldoc?Catalyst%3A%3AView%3A%3ATT>
952 L<http://search.cpan.org/perldoc?Template>
954 =head2 Adding RSS feeds
956 Adding RSS feeds to your Catalyst applications is simple. We'll see two
957 different aproaches here, but the basic premise is that you forward to
958 the normal view action first to get the objects, then handle the output
961 =head3 Using TT templates
963 This is the aproach used in Agave (L<http://dev.rawmode.org/>).
968 $c->stash->{template}='rss.tt';
971 Then you need a template. Here's the one from Agave:
973 <?xml version="1.0" encoding="UTF-8"?>
974 <rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
976 <title>[ [% blog.name || c.config.name || "Agave" %] ] RSS Feed</title>
977 <link>[% base %]</link>
978 <description>Recent posts</description>
979 <language>en-us</language>
981 [% WHILE (post = posts.next) %]
983 <title>[% post.title %]</title>
984 <description>[% post.formatted_teaser|html%]</description>
985 <pubDate>[% post.pub_date %]</pubDate>
986 <guid>[% post.full_uri %]</guid>
987 <link>[% post.full_uri %]</link>
988 <dc:creator>[% post.author.screenname %]</dc:creator>
994 =head3 Using XML::Feed
996 A more robust solution is to use XML::Feed, as was done in the Catalyst
997 Advent Calendar. Assuming we have a C<view> action that populates
998 'entries' with some DBIx::Class iterator, the code would look something
1003 $c->forward('view'); # get the entries
1005 my $feed = XML::Feed->new('RSS');
1006 $feed->title( $c->config->{name} . ' RSS Feed' );
1007 $feed->link( $c->req->base ); # link to the site.
1008 $feed->description('Catalyst advent calendar'); Some description
1010 # Process the entries
1011 while( my $entry = $c->stash->{entries}->next ) {
1012 my $feed_entry = XML::Feed::Entry->new('RSS');
1013 $feed_entry->title($entry->title);
1014 $feed_entry->link( $c->uri_for($entry->link) );
1015 $feed_entry->issued( DateTime->from_epoch(epoch => $entry->created) );
1016 $feed->add_entry($feed_entry);
1018 $c->res->body( $feed->as_xml );
1021 A little more code in the controller, but with this approach you're
1022 pretty sure to get something that validates.
1024 Note that for both of the above aproaches, you'll need to set the
1025 content type like this:
1027 $c->res->content_type('application/rss+xml');
1031 You could generalize the second variant easily by replacing 'RSS' with a
1032 variable, so you can generate Atom feeds with the same code.
1034 Now, go ahead and make RSS feeds for all your stuff. The world *needs*
1035 updates on your goldfish!
1037 =head2 Forcing the browser to download content
1039 Sometimes you need your application to send content for download. For
1040 example, you can generate a comma-separated values (CSV) file for your
1041 users to download and import into their spreadsheet program.
1043 Let's say you have an C<Orders> controller which generates a CSV file
1044 in the C<export> action (i.e., C<http://localhost:3000/orders/export>):
1046 sub export : Local Args(0) {
1047 my ( $self, $c ) = @_;
1049 # In a real application, you'd generate this from the database
1050 my $csv = "1,5.99\n2,29.99\n3,3.99\n";
1052 $c->res->content_type('text/comma-separated-values');
1053 $c->res->body($csv);
1056 Normally the browser uses the last part of the URI to generate a
1057 filename for data it cannot display. In this case your browser would
1058 likely ask you to save a file named C<export>.
1060 Luckily you can have the browser download the content with a specific
1061 filename by setting the C<Content-Disposition> header:
1063 my $filename = 'Important Orders.csv';
1064 $c->res->header('Content-Disposition', qq[attachment; filename="$filename"]);
1066 Note the use of quotes around the filename; this ensures that any
1067 spaces in the filename are handled by the browser.
1069 Put this right before calling C<< $c->res->body >> and your browser
1070 will download a file named C<Important Orders.csv> instead of
1073 You can also use this to have the browser download content which it
1074 normally displays, such as JPEG images or even HTML. Just be sure to
1075 set the appropriate content type and disposition.
1080 Controllers are the main point of communication between the web server
1081 and your application. Here we explore some aspects of how they work.
1083 =head2 Extending RenderView (formerly DefaultEnd)
1085 The recommended approach for an C<end> action is to use
1086 L<Catalyst::Action::RenderView> (taking the place of
1087 L<Catalyst::Plugin::DefaultEnd>), which does what you usually need.
1088 However there are times when you need to add a bit to it, but don't want
1089 to write your own C<end> action.
1091 You can extend it like this:
1093 To add something to an C<end> action that is called before rendering
1094 (this is likely to be what you want), simply place it in the C<end>
1097 sub end : ActionClass('RenderView') {
1098 my ( $self, $c ) = @_;
1099 # do stuff here; the RenderView action is called afterwards
1102 To add things to an C<end> action that are called I<after> rendering,
1103 you can set it up like this:
1105 sub render : ActionClass('RenderView') { }
1108 my ( $self, $c ) = @_;
1109 $c->forward('render');
1117 A Catalyst application is driven by one or more Controller
1118 modules. There are a number of ways that Catalyst can decide which of
1119 the methods in your controller modules it should call. Controller
1120 methods are also called actions, because they determine how your
1121 catalyst application should (re-)act to any given URL. When the
1122 application is started up, catalyst looks at all your actions, and
1123 decides which URLs they map to.
1125 =head3 Type attributes
1127 Each action is a normal method in your controller, except that it has an
1128 L<attribute|http://search.cpan.org/~nwclark/perl-5.8.7/lib/attributes.pm>
1129 attached. These can be one of several types.
1131 Assume our Controller module starts with the following package declaration:
1133 package MyApp::Controller::Buckets;
1135 and we are running our application on localhost, port 3000 (the test
1142 A Path attribute also takes an argument, this can be either a relative
1143 or an absolute path. A relative path will be relative to the
1144 controller namespace, an absolute path will represent an exact
1147 sub my_handles : Path('handles') { .. }
1151 http://localhost:3000/buckets/handles
1155 sub my_handles : Path('/handles') { .. }
1159 http://localhost:3000/handles
1161 See also: L<Catalyst::DispatchType::Path>
1165 When using a Local attribute, no parameters are needed, instead, the
1166 name of the action is matched in the URL. The namespaces created by
1167 the name of the controller package is always part of the URL.
1169 sub my_handles : Local { .. }
1173 http://localhost:3000/buckets/my_handles
1177 A Global attribute is similar to a Local attribute, except that the
1178 namespace of the controller is ignored, and matching starts at root.
1180 sub my_handles : Global { .. }
1184 http://localhost:3000/my_handles
1188 By now you should have figured that a Regex attribute is just what it
1189 sounds like. This one takes a regular expression, and matches starting
1190 from root. These differ from the rest as they can match multiple URLs.
1192 sub my_handles : Regex('^handles') { .. }
1196 http://localhost:3000/handles
1200 http://localhost:3000/handles_and_other_parts
1204 See also: L<Catalyst::DispatchType::Regex>
1208 A LocalRegex is similar to a Regex, except it only matches below the current
1209 controller namespace.
1211 sub my_handles : LocalRegex(^handles') { .. }
1215 http://localhost:3000/buckets/handles
1219 http://localhost:3000/buckets/handles_and_other_parts
1225 See L<Catalyst::DispatchType::Chained> for a description of how the chained
1226 dispatch type works.
1230 Last but not least, there is the Private attribute, which allows you
1231 to create your own internal actions, which can be forwarded to, but
1232 won't be matched as URLs.
1234 sub my_handles : Private { .. }
1236 becomes nothing at all..
1238 Catalyst also predefines some special Private actions, which you can
1239 override, these are:
1245 The default action will be called, if no other matching action is
1246 found. If you don't have one of these in your namespace, or any sub
1247 part of your namespace, you'll get an error page instead. If you want
1248 to find out where it was the user was trying to go, you can look in
1249 the request object using C<< $c->req->path >>.
1251 sub default :Path { .. }
1253 works for all unknown URLs, in this controller namespace, or every one
1254 if put directly into MyApp.pm.
1258 The index action is called when someone tries to visit the exact
1259 namespace of your controller. If index, default and matching Path
1260 actions are defined, then index will be used instead of default and
1263 sub index :Path :Args(0) { .. }
1267 http://localhost:3000/buckets
1271 The begin action is called at the beginning of every request involving
1272 this namespace directly, before other matching actions are called. It
1273 can be used to set up variables/data for this particular part of your
1274 app. A single begin action is called, its always the one most relevant
1275 to the current namespace.
1277 sub begin : Private { .. }
1281 http://localhost:3000/bucket/(anything)?
1287 Like begin, this action is always called for the namespace it is in,
1288 after every other action has finished. It is commonly used to forward
1289 processing to the View component. A single end action is called, its
1290 always the one most relevant to the current namespace.
1293 sub end : Private { .. }
1295 is called once after any actions when
1297 http://localhost:3000/bucket/(anything)?
1303 Lastly, the auto action is magic in that B<every> auto action in the
1304 chain of paths up to and including the ending namespace, will be
1305 called. (In contrast, only one of the begin/end/default actions will
1306 be called, the relevant one).
1308 package MyApp::Controller::Root;
1309 sub auto : Private { .. }
1313 sub auto : Private { .. }
1315 will both be called when visiting
1317 http://localhost:3000/bucket/(anything)?
1323 =head3 A word of warning
1325 You can put root actions in your main MyApp.pm file, but this is deprecated,
1326 please put your actions into your Root controller.
1328 =head3 More Information
1330 L<http://dev.catalyst.perl.org/wiki/FlowChart>
1332 =head2 DRY Controllers with Chained actions.
1334 Imagine that you would like the following paths in your application:
1338 =item B</cd/<ID>/track/<ID>>
1340 Displays info on a particular track.
1342 In the case of a multi-volume CD, this is the track sequence.
1344 =item B</cd/<ID>/volume/<ID>/track/<ID>>
1346 Displays info on a track on a specific volume.
1350 Here is some example code, showing how to do this with chained controllers:
1352 package CD::Controller;
1353 use base qw/Catalyst::Controller/;
1355 sub root : Chained('/') PathPart('/cd') CaptureArgs(1) {
1356 my ($self, $c, $cd_id) = @_;
1357 $c->stash->{cd_id} = $cd_id;
1358 $c->stash->{cd} = $self->model('CD')->find_by_id($cd_id);
1361 sub trackinfo : Chained('track') PathPart('') Args(0) RenderView {
1362 my ($self, $c) = @_;
1365 package CD::Controller::ByTrackSeq;
1366 use base qw/CD::Controller/;
1368 sub track : Chained('root') PathPart('track') CaptureArgs(1) {
1369 my ($self, $c, $track_seq) = @_;
1370 $c->stash->{track} = $self->stash->{cd}->find_track_by_seq($track_seq);
1373 package CD::Controller::ByTrackVolNo;
1374 use base qw/CD::Controller/;
1376 sub volume : Chained('root') PathPart('volume') CaptureArgs(1) {
1377 my ($self, $c, $volume) = @_;
1378 $c->stash->{volume} = $volume;
1381 sub track : Chained('volume') PathPart('track') CaptureArgs(1) {
1382 my ($self, $c, $track_no) = @_;
1383 $c->stash->{track} = $self->stash->{cd}->find_track_by_vol_and_track_no(
1384 $c->stash->{volume}, $track_no
1388 Note that adding other actions (i.e. chain endpoints) which operate on a track
1389 is simply a matter of adding a new sub to CD::Controller - no code is duplicated,
1390 even though there are two different methods of looking up a track.
1392 This technique can be expanded as needed to fulfil your requirements - for example,
1393 if you inherit the first action of a chain from a base class, then mixing in a
1394 different base class can be used to duplicate an entire URL hieratchy at a different
1395 point within your application.
1397 =head2 Component-based Subrequests
1399 See L<Catalyst::Plugin::SubRequest>.
1403 =head3 Single file upload with Catalyst
1405 To implement uploads in Catalyst, you need to have a HTML form similar to
1408 <form action="/upload" method="post" enctype="multipart/form-data">
1409 <input type="hidden" name="form_submit" value="yes">
1410 <input type="file" name="my_file">
1411 <input type="submit" value="Send">
1414 It's very important not to forget C<enctype="multipart/form-data"> in
1417 Catalyst Controller module 'upload' action:
1419 sub upload : Global {
1420 my ($self, $c) = @_;
1422 if ( $c->request->parameters->{form_submit} eq 'yes' ) {
1424 if ( my $upload = $c->request->upload('my_file') ) {
1426 my $filename = $upload->filename;
1427 my $target = "/tmp/upload/$filename";
1429 unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
1430 die( "Failed to copy '$filename' to '$target': $!" );
1435 $c->stash->{template} = 'file_upload.html';
1438 =head3 Multiple file upload with Catalyst
1440 Code for uploading multiple files from one form needs a few changes:
1442 The form should have this basic structure:
1444 <form action="/upload" method="post" enctype="multipart/form-data">
1445 <input type="hidden" name="form_submit" value="yes">
1446 <input type="file" name="file1" size="50"><br>
1447 <input type="file" name="file2" size="50"><br>
1448 <input type="file" name="file3" size="50"><br>
1449 <input type="submit" value="Send">
1452 And in the controller:
1454 sub upload : Local {
1455 my ($self, $c) = @_;
1457 if ( $c->request->parameters->{form_submit} eq 'yes' ) {
1459 for my $field ( $c->req->upload ) {
1461 my $upload = $c->req->upload($field);
1462 my $filename = $upload->filename;
1463 my $target = "/tmp/upload/$filename";
1465 unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
1466 die( "Failed to copy '$filename' to '$target': $!" );
1471 $c->stash->{template} = 'file_upload.html';
1474 C<for my $field ($c-E<gt>req->upload)> loops automatically over all file
1475 input fields and gets input names. After that is basic file saving code,
1476 just like in single file upload.
1478 Notice: C<die>ing might not be what you want to do, when an error
1479 occurs, but it works as an example. A better idea would be to store
1480 error C<$!> in $c->stash->{error} and show a custom error template
1481 displaying this message.
1483 For more information about uploads and usable methods look at
1484 L<Catalyst::Request::Upload> and L<Catalyst::Request>.
1486 =head2 Forwarding with arguments
1488 Sometimes you want to pass along arguments when forwarding to another
1489 action. As of version 5.30, arguments can be passed in the call to
1490 C<forward>; in earlier versions, you can manually set the arguments in
1491 the Catalyst Request object:
1493 # version 5.30 and later:
1494 $c->forward('/wherever', [qw/arg1 arg2 arg3/]);
1497 $c->req->args([qw/arg1 arg2 arg3/]);
1498 $c->forward('/wherever');
1500 (See the L<Catalyst::Manual::Intro> Flow_Control section for more
1501 information on passing arguments via C<forward>.)
1503 =head2 Chained dispatch using base classes, and inner packages.
1505 package MyApp::Controller::Base;
1506 use base qw/Catalyst::Controller/;
1508 sub key1 : Chained('/')
1512 The recipes below describe aspects of the deployment process,
1513 including web server engines and tips to improve application efficiency.
1515 =head2 mod_perl Deployment
1517 mod_perl is the best solution for many applications, but we'll list some pros
1518 and cons so you can decide for yourself. The other production deployment
1519 option is FastCGI, for which see below.
1525 mod_perl is very fast and your app will benefit from being loaded in memory
1526 within each Apache process.
1528 =head4 Shared memory for multiple apps
1530 If you need to run several Catalyst apps on the same server, mod_perl will
1531 share the memory for common modules.
1537 Since your application is fully loaded in memory, every Apache process will
1538 be rather large. This means a large Apache process will be tied up while
1539 serving static files, large files, or dealing with slow clients. For this
1540 reason, it is best to run a two-tiered web architecture with a lightweight
1541 frontend server passing dynamic requests to a large backend mod_perl
1546 Any changes made to the core code of your app require a full Apache restart.
1547 Catalyst does not support Apache::Reload or StatINC. This is another good
1548 reason to run a frontend web server where you can set up an
1549 C<ErrorDocument 502> page to report that your app is down for maintenance.
1551 =head4 Cannot run multiple versions of the same app
1553 It is not possible to run two different versions of the same application in
1554 the same Apache instance because the namespaces will collide.
1558 Now that we have that out of the way, let's talk about setting up mod_perl
1559 to run a Catalyst app.
1561 =head4 1. Install Catalyst::Engine::Apache
1563 You should install the latest versions of both Catalyst and
1564 Catalyst::Engine::Apache. The Apache engines were separated from the
1565 Catalyst core in version 5.50 to allow for updates to the engine without
1566 requiring a new Catalyst release.
1568 =head4 2. Install Apache with mod_perl
1570 Both Apache 1.3 and Apache 2 are supported, although Apache 2 is highly
1571 recommended. With Apache 2, make sure you are using the prefork MPM and not
1572 the worker MPM. The reason for this is that many Perl modules are not
1573 thread-safe and may have problems running within the threaded worker
1574 environment. Catalyst is thread-safe however, so if you know what you're
1575 doing, you may be able to run using worker.
1577 In Debian, the following commands should get you going.
1579 apt-get install apache2-mpm-prefork
1580 apt-get install libapache2-mod-perl2
1582 =head4 3. Configure your application
1584 Every Catalyst application will automagically become a mod_perl handler
1585 when run within mod_perl. This makes the configuration extremely easy.
1586 Here is a basic Apache 2 configuration.
1588 PerlSwitches -I/var/www/MyApp/lib
1593 PerlResponseHandler MyApp
1596 The most important line here is C<PerlModule MyApp>. This causes mod_perl
1597 to preload your entire application into shared memory, including all of your
1598 controller, model, and view classes and configuration. If you have -Debug
1599 mode enabled, you will see the startup output scroll by when you first
1602 For an example Apache 1.3 configuration, please see the documentation for
1603 L<Catalyst::Engine::Apache::MP13>.
1607 That's it, your app is now a full-fledged mod_perl application! Try it out
1608 by going to http://your.server.com/.
1610 =head3 Other Options
1612 =head4 Non-root location
1614 You may not always want to run your app at the root of your server or virtual
1615 host. In this case, it's a simple change to run at any non-root location
1620 PerlResponseHandler MyApp
1623 When running this way, it is best to make use of the C<uri_for> method in
1624 Catalyst for constructing correct links.
1626 =head4 Static file handling
1628 Static files can be served directly by Apache for a performance boost.
1630 DocumentRoot /var/www/MyApp/root
1632 SetHandler default-handler
1635 This will let all files within root/static be handled directly by Apache. In
1636 a two-tiered setup, the frontend server should handle static files.
1637 The configuration to do this on the frontend will vary.
1639 The same is accomplished in lighttpd with the following snippet:
1641 $HTTP["url"] !~ "^/(?:img/|static/|css/|favicon.ico$)" {
1645 "socket" => "/tmp/myapp.socket",
1646 "check-local" => "disable",
1652 Which serves everything in the img, static, css directories
1653 statically, as well as the favicon file.
1655 Note the path of the application needs to be stated explicitly in the
1656 web server configuration for both these recipes.
1658 =head2 Catalyst on shared hosting
1660 So, you want to put your Catalyst app out there for the whole world to
1661 see, but you don't want to break the bank. There is an answer - if you
1662 can get shared hosting with FastCGI and a shell, you can install your
1663 Catalyst app in a local directory on your shared host. First, run
1665 perl -MCPAN -e shell
1667 and go through the standard CPAN configuration process. Then exit out
1668 without installing anything. Next, open your .bashrc and add
1670 export PATH=$HOME/local/bin:$HOME/local/script:$PATH
1671 perlversion=`perl -v | grep 'built for' | awk '{print $4}' | sed -e 's/v//;'`
1672 export PERL5LIB=$HOME/local/share/perl/$perlversion:$HOME/local/lib/perl/$perlversion:$HOME/local/lib:$PERL5LIB
1674 and log out, then back in again (or run C<". .bashrc"> if you
1675 prefer). Finally, edit C<.cpan/CPAN/MyConfig.pm> and add
1677 'make_install_arg' => qq[SITEPREFIX=$ENV{HOME}/local],
1678 'makepl_arg' => qq[INSTALLDIRS=site install_base=$ENV{HOME}/local],
1680 Now you can install the modules you need using CPAN as normal; they
1681 will be installed into your local directory, and perl will pick them
1682 up. Finally, change directory into the root of your virtual host and
1683 symlink your application's script directory in:
1685 cd path/to/mydomain.com
1686 ln -s ~/lib/MyApp/script script
1688 And add the following lines to your .htaccess file (assuming the server
1689 is setup to handle .pl as fcgi - you may need to rename the script to
1690 myapp_fastcgi.fcgi and/or use a SetHandler directive):
1693 RewriteCond %{REQUEST_URI} !^/?script/myapp_fastcgi.pl
1694 RewriteRule ^(.*)$ script/myapp_fastcgi.pl/$1 [PT,L]
1696 Now C<http://mydomain.com/> should now Just Work. Congratulations, now
1697 you can tell your friends about your new website (or in our case, tell
1698 the client it's time to pay the invoice :) )
1700 =head2 FastCGI Deployment
1702 FastCGI is a high-performance extension to CGI. It is suitable
1703 for production environments.
1709 FastCGI performs equally as well as mod_perl. Don't let the 'CGI' fool you;
1710 your app runs as multiple persistent processes ready to receive connections
1711 from the web server.
1715 When using external FastCGI servers, your application runs as a standalone
1716 application server. It may be restarted independently from the web server.
1717 This allows for a more robust environment and faster reload times when
1718 pushing new app changes. The frontend server can even be configured to
1719 display a friendly "down for maintenance" page while the application is
1722 =head4 Load-balancing
1724 You can launch your application on multiple backend servers and allow the
1725 frontend web server to load-balance between all of them. And of course, if
1726 one goes down, your app continues to run fine.
1728 =head4 Multiple versions of the same app
1730 Each FastCGI application is a separate process, so you can run different
1731 versions of the same app on a single server.
1733 =head4 Can run with threaded Apache
1735 Since your app is not running inside of Apache, the faster mpm_worker module
1736 can be used without worrying about the thread safety of your application.
1740 You may have to disable mod_deflate. If you experience page hangs with
1741 mod_fastcgi then remove deflate.load and deflate.conf from mods-enabled/
1743 =head4 More complex environment
1745 With FastCGI, there are more things to monitor and more processes running
1746 than when using mod_perl.
1750 =head4 1. Install Apache with mod_fastcgi
1752 mod_fastcgi for Apache is a third party module, and can be found at
1753 L<http://www.fastcgi.com/>. It is also packaged in many distributions,
1754 for example, libapache2-mod-fastcgi in Debian.
1756 =head4 2. Configure your application
1758 # Serve static content directly
1759 DocumentRoot /var/www/MyApp/root
1760 Alias /static /var/www/MyApp/root/static
1762 FastCgiServer /var/www/MyApp/script/myapp_fastcgi.pl -processes 3
1763 Alias /myapp/ /var/www/MyApp/script/myapp_fastcgi.pl/
1765 # Or, run at the root
1766 Alias / /var/www/MyApp/script/myapp_fastcgi.pl/
1768 The above commands will launch 3 app processes and make the app available at
1771 =head3 Standalone server mode
1773 While not as easy as the previous method, running your app as an external
1774 server gives you much more flexibility.
1776 First, launch your app as a standalone server listening on a socket.
1778 script/myapp_fastcgi.pl -l /tmp/myapp.socket -n 5 -p /tmp/myapp.pid -d
1780 You can also listen on a TCP port if your web server is not on the same
1783 script/myapp_fastcgi.pl -l :8080 -n 5 -p /tmp/myapp.pid -d
1785 You will probably want to write an init script to handle starting/stopping
1786 of the app using the pid file.
1788 Now, we simply configure Apache to connect to the running server.
1790 # 502 is a Bad Gateway error, and will occur if the backend server is down
1791 # This allows us to display a friendly static page that says "down for
1793 Alias /_errors /var/www/MyApp/root/error-pages
1794 ErrorDocument 502 /_errors/502.html
1796 FastCgiExternalServer /tmp/myapp.fcgi -socket /tmp/myapp.socket
1797 Alias /myapp/ /tmp/myapp.fcgi/
1799 # Or, run at the root
1800 Alias / /tmp/myapp.fcgi/
1804 L<Catalyst::Engine::FastCGI>.
1806 =head2 Development server deployment
1808 The development server is a mini web server written in perl. If you
1809 expect a low number of hits or you don't need mod_perl/FastCGI speed,
1810 you could use the development server as the application server with a
1811 lightweight proxy web server at the front. However, consider using
1812 L<Catalyst::Engine::HTTP::Prefork> for this kind of deployment instead, since
1813 it can better handle multiple concurrent requests without forking, or can
1814 prefork a set number of servers for improved performance.
1818 As this is an application server setup, the pros are the same as
1819 FastCGI (with the exception of speed).
1824 The development server is what you create your code on, so if it works
1825 here, it should work in production!
1831 Not as fast as mod_perl or FastCGI. Needs to fork for each request
1832 that comes in - make sure static files are served by the web server to
1837 =head4 Start up the development server
1839 script/myapp_server.pl -p 8080 -k -f -pidfile=/tmp/myapp.pid
1841 You will probably want to write an init script to handle stop/starting
1842 the app using the pid file.
1844 =head4 Configuring Apache
1846 Make sure mod_proxy is enabled and add:
1848 # Serve static content directly
1849 DocumentRoot /var/www/MyApp/root
1850 Alias /static /var/www/MyApp/root/static
1858 # Need to specifically stop these paths from being passed to proxy
1860 ProxyPass /favicon.ico !
1862 ProxyPass / http://localhost:8080/
1863 ProxyPassReverse / http://localhost:8080/
1865 # This is optional if you'd like to show a custom error page
1866 # if the proxy is not available
1867 ErrorDocument 502 /static/error_pages/http502.html
1869 You can wrap the above within a VirtualHost container if you want
1870 different apps served on the same host.
1872 =head2 Quick deployment: Building PAR Packages
1874 You have an application running on your development box, but then you
1875 have to quickly move it to another one for
1876 demonstration/deployment/testing...
1878 PAR packages can save you from a lot of trouble here. They are usual Zip
1879 files that contain a blib tree; you can even include all prereqs and a
1880 perl interpreter by setting a few flags!
1882 =head3 Follow these few points to try it out!
1884 1. Install Catalyst and PAR 0.89 (or later)
1886 % perl -MCPAN -e 'install Catalyst'
1888 % perl -MCPAN -e 'install PAR'
1891 2. Create a application
1897 Recent versions of Catalyst (5.62 and up) include
1898 L<Module::Install::Catalyst>, which simplifies the process greatly. From the shell in your application directory:
1903 You can customise the PAR creation process by special "catalyst_par_*" commands
1904 available from L<Module::Install::Catalyst>. You can add these commands in your
1905 Makefile.PL just before the line containing "catalyst;"
1907 #Makefile.PL example with extra PAR options
1908 use inc::Module::Install;
1911 all_from 'lib\MyApp.pm';
1913 requires 'Catalyst::Runtime' => '5.80005';
1918 catalyst_par_core(1); # bundle perl core modules in the resulting PAR
1919 catalyst_par_multiarch(1); # build a multi-architecture PAR file
1920 catalyst_par_classes(qw/
1921 Some::Additional::Module
1923 /); # specify additional modules you want to be included into PAR
1926 install_script glob('script/*.pl');
1930 Congratulations! Your package "myapp.par" is ready, the following
1931 steps are just optional.
1933 3. Test your PAR package with "parl" (no typo)
1937 [parl] myapp[.par] [script] [arguments]
1940 parl myapp.par myapp_server.pl -r
1950 % parl myapp.par myapp_server.pl
1951 You can connect to your server at http://localhost:3000
1953 Yes, this nifty little starter application gets automatically included.
1954 You can also use "catalyst_par_script('myapp_server.pl')" to set a
1955 default script to execute.
1957 6. Want to create a binary that includes the Perl interpreter?
1959 % pp -o myapp myapp.par
1960 % ./myapp myapp_server.pl
1961 You can connect to your server at http://localhost:3000
1963 =head2 Serving static content
1965 Serving static content in Catalyst used to be somewhat tricky; the use
1966 of L<Catalyst::Plugin::Static::Simple> makes everything much easier.
1967 This plugin will automatically serve your static content during development,
1968 but allows you to easily switch to Apache (or other server) in a
1969 production environment.
1971 =head3 Introduction to Static::Simple
1973 Static::Simple is a plugin that will help to serve static content for your
1974 application. By default, it will serve most types of files, excluding some
1975 standard Template Toolkit extensions, out of your B<root> file directory. All
1976 files are served by path, so if B<images/me.jpg> is requested, then
1977 B<root/images/me.jpg> is found and served.
1981 Using the plugin is as simple as setting your use line in MyApp.pm to include:
1983 use Catalyst qw/Static::Simple/;
1985 and already files will be served.
1989 Static content is best served from a single directory within your root
1990 directory. Having many different directories such as C<root/css> and
1991 C<root/images> requires more code to manage, because you must separately
1992 identify each static directory--if you decide to add a C<root/js>
1993 directory, you'll need to change your code to account for it. In
1994 contrast, keeping all static directories as subdirectories of a main
1995 C<root/static> directory makes things much easier to manage. Here's an
1996 example of a typical root directory structure:
2000 root/controller/stuff.tt
2003 root/static/css/main.css
2004 root/static/images/logo.jpg
2005 root/static/js/code.js
2008 All static content lives under C<root/static>, with everything else being
2009 Template Toolkit files.
2015 You may of course want to change the default locations, and make
2016 Static::Simple look somewhere else, this is as easy as:
2018 MyApp->config->{static}->{include_path} = [
2019 MyApp->config->{root},
2023 When you override include_path, it will not automatically append the
2024 normal root path, so you need to add it yourself if you still want
2025 it. These will be searched in order given, and the first matching file
2028 =item Static directories
2030 If you want to force some directories to be only static, you can set
2031 them using paths relative to the root dir, or regular expressions:
2033 MyApp->config->{static}->{dirs} = [
2038 =item File extensions
2040 By default, the following extensions are not served (that is, they will
2041 be processed by Catalyst): B<tmpl, tt, tt2, html, xhtml>. This list can
2044 MyApp->config->{static}->{ignore_extensions} = [
2045 qw/tmpl tt tt2 html xhtml/
2048 =item Ignoring directories
2050 Entire directories can be ignored. If used with include_path,
2051 directories relative to the include_path dirs will also be ignored:
2053 MyApp->config->{static}->{ignore_dirs} = [ qw/tmpl css/ ];
2057 =head3 More information
2059 L<http://search.cpan.org/dist/Catalyst-Plugin-Static-Simple/>
2061 =head3 Serving manually with the Static plugin with HTTP::Daemon (myapp_server.pl)
2063 In some situations you might want to control things more directly,
2064 using L<Catalyst::Plugin::Static>.
2066 In your main application class (MyApp.pm), load the plugin:
2068 use Catalyst qw/-Debug FormValidator Static OtherPlugin/;
2070 You will also need to make sure your end method does I<not> forward
2071 static content to the view, perhaps like this:
2074 my ( $self, $c ) = @_;
2076 $c->forward( 'MyApp::View::TT' )
2077 unless ( $c->res->body || !$c->stash->{template} );
2080 This code will only forward to the view if a template has been
2081 previously defined by a controller and if there is not already data in
2082 C<$c-E<gt>res-E<gt>body>.
2084 Next, create a controller to handle requests for the /static path. Use
2085 the Helper to save time. This command will create a stub controller as
2086 C<lib/MyApp/Controller/Static.pm>.
2088 $ script/myapp_create.pl controller Static
2090 Edit the file and add the following methods:
2092 # serve all files under /static as static files
2093 sub default : Path('/static') {
2094 my ( $self, $c ) = @_;
2096 # Optional, allow the browser to cache the content
2097 $c->res->headers->header( 'Cache-Control' => 'max-age=86400' );
2099 $c->serve_static; # from Catalyst::Plugin::Static
2102 # also handle requests for /favicon.ico
2103 sub favicon : Path('/favicon.ico') {
2104 my ( $self, $c ) = @_;
2109 You can also define a different icon for the browser to use instead of
2110 favicon.ico by using this in your HTML header:
2112 <link rel="icon" href="/static/myapp.ico" type="image/x-icon" />
2114 =head3 Common problems with the Static plugin
2116 The Static plugin makes use of the C<shared-mime-info> package to
2117 automatically determine MIME types. This package is notoriously
2118 difficult to install, especially on win32 and OS X. For OS X the easiest
2119 path might be to install Fink, then use C<apt-get install
2120 shared-mime-info>. Restart the server, and everything should be fine.
2122 Make sure you are using the latest version (>= 0.16) for best
2123 results. If you are having errors serving CSS files, or if they get
2124 served as text/plain instead of text/css, you may have an outdated
2125 shared-mime-info version. You may also wish to simply use the following
2126 code in your Static controller:
2128 if ($c->req->path =~ /css$/i) {
2129 $c->serve_static( "text/css" );
2134 =head3 Serving Static Files with Apache
2136 When using Apache, you can bypass Catalyst and any Static
2137 plugins/controllers controller by intercepting requests for the
2138 C<root/static> path at the server level. All that is required is to
2139 define a DocumentRoot and add a separate Location block for your static
2140 content. Here is a complete config for this application under mod_perl
2144 use lib qw(/var/www/MyApp/lib);
2149 ServerName myapp.example.com
2150 DocumentRoot /var/www/MyApp/root
2152 SetHandler perl-script
2155 <LocationMatch "/(static|favicon.ico)">
2156 SetHandler default-handler
2160 And here's a simpler example that'll get you started:
2162 Alias /static/ "/my/static/files/"
2163 <Location "/static">
2169 Catalyst makes it easy to employ several different types of caching to
2170 speed up your applications.
2172 =head3 Cache Plugins
2174 There are three wrapper plugins around common CPAN cache modules:
2175 Cache::FastMmap, Cache::FileCache, and Cache::Memcached. These can be
2176 used to cache the result of slow operations.
2178 The Catalyst Advent Calendar uses the FileCache plugin to cache the
2179 rendered XHTML version of the source POD document. This is an ideal
2180 application for a cache because the source document changes
2181 infrequently but may be viewed many times.
2183 use Catalyst qw/Cache::FileCache/;
2188 sub render_pod : Local {
2189 my ( self, $c ) = @_;
2191 # the cache is keyed on the filename and the modification time
2192 # to check for updates to the file.
2193 my $file = $c->path_to( 'root', '2005', '11.pod' );
2194 my $mtime = ( stat $file )->mtime;
2196 my $cached_pod = $c->cache->get("$file $mtime");
2197 if ( !$cached_pod ) {
2198 $cached_pod = do_slow_pod_rendering();
2199 # cache the result for 12 hours
2200 $c->cache->set( "$file $mtime", $cached_pod, '12h' );
2202 $c->stash->{pod} = $cached_pod;
2205 We could actually cache the result forever, but using a value such as 12 hours
2206 allows old entries to be automatically expired when they are no longer needed.
2210 Another method of caching is to cache the entire HTML page. While this is
2211 traditionally handled by a front-end proxy server like Squid, the Catalyst
2212 PageCache plugin makes it trivial to cache the entire output from
2213 frequently-used or slow actions.
2215 Many sites have a busy content-filled front page that might look something
2216 like this. It probably takes a while to process, and will do the exact same
2217 thing for every single user who views the page.
2219 sub front_page : Path('/') {
2220 my ( $self, $c ) = @_;
2222 $c->forward( 'get_news_articles' );
2223 $c->forward( 'build_lots_of_boxes' );
2224 $c->forward( 'more_slow_stuff' );
2226 $c->stash->{template} = 'index.tt';
2229 We can add the PageCache plugin to speed things up.
2231 use Catalyst qw/Cache::FileCache PageCache/;
2233 sub front_page : Path ('/') {
2234 my ( $self, $c ) = @_;
2236 $c->cache_page( 300 );
2238 # same processing as above
2241 Now the entire output of the front page, from <html> to </html>, will be
2242 cached for 5 minutes. After 5 minutes, the next request will rebuild the
2243 page and it will be re-cached.
2245 Note that the page cache is keyed on the page URI plus all parameters, so
2246 requests for / and /?foo=bar will result in different cache items. Also,
2247 only GET requests will be cached by the plugin.
2249 You can even get that front-end Squid proxy to help out by enabling HTTP
2250 headers for the cached page.
2252 MyApp->config->{page_cache}->{set_http_headers} = 1;
2254 This would now set the following headers so proxies and browsers may cache
2255 the content themselves.
2257 Cache-Control: max-age=($expire_time - time)
2258 Expires: $expire_time
2259 Last-Modified: $cache_created_time
2261 =head3 Template Caching
2263 Template Toolkit provides support for caching compiled versions of your
2264 templates. To enable this in Catalyst, use the following configuration.
2265 TT will cache compiled templates keyed on the file mtime, so changes will
2266 still be automatically detected.
2268 package MyApp::View::TT;
2272 use base 'Catalyst::View::TT';
2274 __PACKAGE__->config(
2275 COMPILE_DIR => '/tmp/template_cache',
2282 See the documentation for each cache plugin for more details and other
2283 available configuration options.
2285 L<Catalyst::Plugin::Cache::FastMmap>
2286 L<Catalyst::Plugin::Cache::FileCache>
2287 L<Catalyst::Plugin::Cache::Memcached>
2288 L<Catalyst::Plugin::PageCache>
2289 L<http://search.cpan.org/dist/Template-Toolkit/lib/Template/Manual/Config.pod#Caching_and_Compiling_Options>
2293 Testing is an integral part of the web application development
2294 process. Tests make multi developer teams easier to coordinate, and
2295 they help ensure that there are no nasty surprises after upgrades or
2300 Catalyst provides a convenient way of testing your application during
2301 development and before deployment in a real environment.
2303 C<Catalyst::Test> makes it possible to run the same tests both locally
2304 (without an external daemon) and against a remote server via HTTP.
2308 Let's examine a skeleton application's C<t/> directory:
2310 mundus:~/MyApp chansen$ ls -l t/
2312 -rw-r--r-- 1 chansen chansen 95 18 Dec 20:50 01app.t
2313 -rw-r--r-- 1 chansen chansen 190 18 Dec 20:50 02pod.t
2314 -rw-r--r-- 1 chansen chansen 213 18 Dec 20:50 03podcoverage.t
2320 Verifies that the application loads, compiles, and returns a successful
2325 Verifies that all POD is free from errors. Only executed if the C<TEST_POD>
2326 environment variable is true.
2328 =item C<03podcoverage.t>
2330 Verifies that all methods/functions have POD coverage. Only executed if the
2331 C<TEST_POD> environment variable is true.
2335 =head3 Creating tests
2337 mundus:~/MyApp chansen$ cat t/01app.t | perl -ne 'printf( "%2d %s", $., $_ )'
2338 1 use Test::More tests => 2;
2339 2 use_ok( Catalyst::Test, 'MyApp' );
2341 4 ok( request('/')->is_success );
2343 The first line declares how many tests we are going to run, in this case
2344 two. The second line tests and loads our application in test mode. The
2345 fourth line verifies that our application returns a successful response.
2347 C<Catalyst::Test> exports two functions, C<request> and C<get>. Each can
2348 take three different arguments:
2352 =item A string which is a relative or absolute URI.
2354 request('/my/path');
2355 request('http://www.host.com/my/path');
2357 =item An instance of C<URI>.
2359 request( URI->new('http://www.host.com/my/path') );
2361 =item An instance of C<HTTP::Request>.
2363 request( HTTP::Request->new( GET => 'http://www.host.com/my/path') );
2367 C<request> returns an instance of C<HTTP::Response> and C<get> returns the
2368 content (body) of the response.
2370 =head3 Running tests locally
2372 mundus:~/MyApp chansen$ CATALYST_DEBUG=0 TEST_POD=1 prove --lib lib/ t/
2373 t/01app............ok
2374 t/02pod............ok
2375 t/03podcoverage....ok
2376 All tests successful.
2377 Files=3, Tests=4, 2 wallclock secs ( 1.60 cusr + 0.36 csys = 1.96 CPU)
2379 C<CATALYST_DEBUG=0> ensures that debugging is off; if it's enabled you
2380 will see debug logs between tests.
2382 C<TEST_POD=1> enables POD checking and coverage.
2384 C<prove> A command-line tool that makes it easy to run tests. You can
2385 find out more about it from the links below.
2387 =head3 Running tests remotely
2389 mundus:~/MyApp chansen$ CATALYST_SERVER=http://localhost:3000/ prove --lib lib/ t/01app.t
2391 All tests successful.
2392 Files=1, Tests=2, 0 wallclock secs ( 0.40 cusr + 0.01 csys = 0.41 CPU)
2394 C<CATALYST_SERVER=http://localhost:3000/> is the absolute deployment URI of
2395 your application. In C<CGI> or C<FastCGI> it should be the host and path
2398 =head3 C<Test::WWW::Mechanize> and Catalyst
2400 Be sure to check out C<Test::WWW::Mechanize::Catalyst>. It makes it easy to
2401 test HTML, forms and links. A short example of usage:
2403 use Test::More tests => 6;
2404 use_ok( Test::WWW::Mechanize::Catalyst, 'MyApp' );
2406 my $mech = Test::WWW::Mechanize::Catalyst->new;
2407 $mech->get_ok("http://localhost/", 'Got index page');
2408 $mech->title_like( qr/^MyApp on Catalyst/, 'Got right index title' );
2409 ok( $mech->find_link( text_regex => qr/^Wiki/i ), 'Found link to Wiki' );
2410 ok( $mech->find_link( text_regex => qr/^Mailing-List/i ), 'Found link to Mailing-List' );
2411 ok( $mech->find_link( text_regex => qr/^IRC channel/i ), 'Found link to IRC channel' );
2413 =head3 Further Reading
2417 =item Catalyst::Test
2419 L<http://search.cpan.org/dist/Catalyst/lib/Catalyst/Test.pm>
2421 =item Test::WWW::Mechanize::Catalyst
2423 L<http://search.cpan.org/dist/Test-WWW-Mechanize-Catalyst/lib/Test/WWW/Mechanize/Catalyst.pm>
2425 =item Test::WWW::Mechanize
2427 L<http://search.cpan.org/dist/Test-WWW-Mechanize/Mechanize.pm>
2429 =item WWW::Mechanize
2431 L<http://search.cpan.org/dist/WWW-Mechanize/lib/WWW/Mechanize.pm>
2433 =item LWP::UserAgent
2435 L<http://search.cpan.org/dist/libwww-perl/lib/LWP/UserAgent.pm>
2439 L<http://search.cpan.org/dist/libwww-perl/lib/HTML/Form.pm>
2443 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Message.pm>
2447 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request.pm>
2449 =item HTTP::Request::Common
2451 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request/Common.pm>
2453 =item HTTP::Response
2455 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Response.pm>
2459 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Status.pm>
2463 L<http://search.cpan.org/dist/URI/URI.pm>
2467 L<http://search.cpan.org/dist/Test-Simple/lib/Test/More.pm>
2471 L<http://search.cpan.org/dist/Test-Pod/Pod.pm>
2473 =item Test::Pod::Coverage
2475 L<http://search.cpan.org/dist/Test-Pod-Coverage/Coverage.pm>
2477 =item prove (Test::Harness)
2479 L<http://search.cpan.org/dist/Test-Harness/bin/prove>
2483 =head3 More Information
2485 L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authorization::Roles>
2486 L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authorization::ACL>
2490 Catalyst Contributors, see Catalyst.pm
2494 This library is free software. You can redistribute it and/or modify it under
2495 the same terms as Perl itself.