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 (or C<__PACKAGE__->setup(qw/-Debug/)
66 ). However, you can also enable it using environment variable, so you
67 can (for example) get debug info without modifying your application
68 scripts. Just set C<CATALYST_DEBUG> or C<E<lt>MYAPPE<gt>_DEBUG> to a
73 When you have your users identified, you will want to somehow remember
74 that fact, to save them from having to identify themselves for every
75 single page. One way to do this is to send the username and password
76 parameters in every single page, but that's ugly, and won't work for
79 Sessions are a method of saving data related to some transaction, and
80 giving the whole collection a single ID. This ID is then given to the
81 user to return to us on every page they visit while logged in. The
82 usual way to do this is using a browser cookie.
84 Catalyst uses two types of plugins to represent sessions:
88 A State module is used to keep track of the state of the session
89 between the users browser, and your application.
91 A common example is the Cookie state module, which sends the browser a
92 cookie containing the session ID. It will use default value for the
93 cookie name and domain, so will "just work" when used.
97 A Store module is used to hold all the data relating to your session,
98 for example the users ID, or the items for their shopping cart. You
99 can store data in memory (FastMmap), in a file (File) or in a database
102 =head3 Authentication magic
104 If you have included the session modules in your application, the
105 Authentication modules will automagically use your session to save and
106 retrieve the user data for you.
108 =head3 Using a session
110 Once the session modules are loaded, the session is available as C<<
111 $c->session >>, and can be writen to and read from as a simple hash
116 use parent qw/Catalyst/;
117 __PACKAGE__->setup( qw/
119 Session::Store::FastMmap
120 Session::State::Cookie
124 ## Write data into the session
126 sub add_item : Local {
127 my ( $self, $c ) = @_;
129 my $item_id = $c->req->param("item");
131 push @{ $c->session->{items} }, $item_id;
135 ## A page later we retrieve the data from the session:
137 sub get_items : Local {
138 my ( $self, $c ) = @_;
140 $c->stash->{items_to_display} = $c->session->{items};
145 =head3 More information
147 L<http://search.cpan.org/dist/Catalyst-Plugin-Session>
149 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-Cookie>
151 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-State-URI>
153 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-FastMmap>
155 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-File>
157 L<http://search.cpan.org/dist/Catalyst-Plugin-Session-Store-DBI>
159 =head2 Configure your application
161 You configure your application with the C<config> method in your
162 application class. This can be hard-coded, or brought in from a
163 separate configuration file.
165 =head3 Using Config::General
167 L<Config::General|Config::General> is a method for creating flexible
168 and readable configuration files. It's a great way to keep your
169 Catalyst application configuration in one easy-to-understand location.
171 Now create C<myapp.conf> in your application home:
175 # session; perldoc Catalyst::Plugin::Session::FastMmap
179 storage /tmp/myapp.session
182 # emails; perldoc Catalyst::Plugin::Email
183 # this passes options as an array :(
187 This is equivalent to:
189 # configure base package
190 __PACKAGE__->config( name => MyApp );
191 # configure authentication
192 __PACKAGE__->config->{authentication} = {
193 user_class => 'MyApp::Model::MyDB::Customer',
197 __PACKAGE__->config->{session} = {
201 # configure email sending
202 __PACKAGE__->config->{email} = [qw/SMTP localhost/];
204 See also L<Config::General|Config::General>.
206 =head1 Skipping your VCS's directories
208 Catalyst uses Module::Pluggable to load Models, Views and Controllers.
209 Module::Pluggable will scan through all directories and load modules
210 it finds. Sometimes you might want to skip some of these directories,
211 for example when your version control system makes a subdirectory with
212 meta-information in every version-controlled directory. While
213 Catalyst skips subversion and CVS directories already, there are other
214 source control systems. Here is the configuration you need to add
215 their directories to the list to skip.
217 You can make catalyst skip these directories using the Catalyst config:
219 # Configure the application
222 setup_components => { except => qr/SCCS/ },
225 See the Module::Pluggable manual page for more information on B<except>
228 =head1 Users and Access Control
230 Most multiuser, and some single user web applications require that
231 users identify themselves, and the application is often required to
232 define those roles. The recipes below describe some ways of doing
235 =head2 Authentication (logging in)
237 This is extensively covered in other documentation; see in particular
238 L<Catalyst::Plugin::Authentication> and the Authentication chapter
239 of the Tutorial at L<Catalyst::Manual::Tutorial::Authorization>.
241 =head2 Pass-through login (and other actions)
243 An easy way of having assorted actions that occur during the processing
244 of a request that are orthogonal to its actual purpose - logins, silent
245 commands etc. Provide actions for these, but when they're required for
246 something else fill e.g. a form variable __login and have a sub begin
249 sub begin : Private {
251 foreach my $action (qw/login docommand foo bar whatever/) {
252 if ($c->req->params->{"__${action}"}) {
253 $c->forward($action);
259 =head2 Role-based Authorization
261 For more advanced access control, you may want to consider using role-based
262 authorization. This means you can assign different roles to each user, e.g.
263 "user", "admin", etc.
265 The C<login> and C<logout> methods and view template are exactly the same as
266 in the previous example.
268 The L<Catalyst::Plugin::Authorization::Roles> plugin is required when
271 use parent qw/Catalyst/;
272 __PACKAGE__->setup (qw/
274 Authentication::Credential::Password
275 Authentication::Store::Htpasswd
279 Roles are implemented automatically when using
280 L<Catalyst::Authentication::Store::Htpasswd>:
282 # no additional role configuration required
283 __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
285 Or can be set up manually when using L<Catalyst::Authentication::Store::DBIC>:
287 # Authorization using a many-to-many role relationship
288 __PACKAGE__->config->{authorization}{dbic} = {
289 'role_class' => 'My::Model::DBIC::Role',
290 'role_field' => 'name',
291 'user_role_user_field' => 'user',
293 # DBIx::Class only (omit if using Class::DBI)
294 'role_rel' => 'user_role',
296 # Class::DBI only, (omit if using DBIx::Class)
297 'user_role_class' => 'My::Model::CDBI::UserRole'
298 'user_role_role_field' => 'role',
301 To restrict access to any action, you can use the C<check_user_roles> method:
303 sub restricted : Local {
304 my ( $self, $c ) = @_;
306 $c->detach("unauthorized")
307 unless $c->check_user_roles( "admin" );
309 # do something restricted here
312 You can also use the C<assert_user_roles> method. This just gives an
313 error if the current user does not have one of the required roles:
315 sub also_restricted : Global {
316 my ( $self, $c ) = @_;
317 $c->assert_user_roles( qw/ user admin / );
320 =head2 Authentication/Authorization
322 This is done in several steps:
328 Getting the user to identify themselves, by giving you some piece of
329 information known only to you and the user. Then you can assume that
330 the user is who they say they are. This is called B<credential
335 Making sure the user only accesses functions you want them to
336 access. This is done by checking the verified users data against your
337 internal list of groups, or allowed persons for the current page.
343 The Catalyst Authentication system is made up of many interacting
344 modules, to give you the most flexibility possible.
346 =head4 Credential verifiers
348 A Credential module tables the user input, and passes it to a Store,
349 or some other system, for verification. Typically, a user object is
350 created by either this module or the Store and made accessible by a
351 C<< $c->user >> call.
355 Password - Simple username/password checking.
356 HTTPD - Checks using basic HTTP auth.
357 TypeKey - Check using the typekey system.
359 =head3 Storage backends
361 A Storage backend contains the actual data representing the users. It
362 is queried by the credential verifiers. Updating the store is not done
363 within this system, you will need to do it yourself.
367 DBIC - Storage using a database.
368 Minimal - Storage using a simple hash (for testing).
372 A User object is created by either the storage backend or the
373 credential verifier, and filled with the retrieved user information.
377 Hash - A simple hash of keys and values.
379 =head3 ACL authorization
381 ACL stands for Access Control List. The ACL plugin allows you to
382 regulate access on a path by path basis, by listing which users, or
383 roles, have access to which paths.
385 =head3 Roles authorization
387 Authorization by roles is for assigning users to groups, which can
388 then be assigned to ACLs, or just checked when needed.
392 When you have chosen your modules, all you need to do is call the C<<
393 $c->login >> method. If called with no parameters, it will try to find
394 suitable parameters, such as B<username> and B<password>, or you can
395 pass it these values.
397 =head3 Checking roles
399 Role checking is done by using the C<< $c->check_user_roles >> method,
400 this will check using the currently logged in user (via C<< $c->user
401 >>). You pass it the name of a role to check, and it returns true if
402 the user is a member.
406 use parent qw/Catalyst/;
407 __PACKAGE__->setup( qw/Authentication
408 Authentication::Credential::Password
409 Authentication::Store::Htpasswd
410 Authorization::Roles/);
412 __PACKAGE__->config->{authentication}{htpasswd} = "passwdfile";
417 if ( my $user = $c->req->param("user")
418 and my $password = $c->req->param("password") )
420 if ( $c->login( $user, $password ) ) {
421 $c->res->body( "hello " . $c->user->name );
431 sub restricted : Local {
432 my ( $self, $c ) = @_;
434 $c->detach("unauthorized")
435 unless $c->check_user_roles( "admin" );
437 # do something restricted here
440 =head3 Using authentication in a testing environment
442 Ideally, to write tests for authentication/authorization code one
443 would first set up a test database with known data, then use
444 L<Test::WWW::Mechanize::Catalyst> to simulate a user logging
445 in. Unfortunately the former can be rather awkward, which is why it's
446 a good thing that the authentication framework is so flexible.
448 Instead of using a test database, one can simply change the
449 authentication store to something a bit easier to deal with in a
450 testing environment. Additionally, this has the advantage of not
451 modifying one's database, which can be problematic if one forgets to
452 use the testing instead of production database.
456 use Catalyst::Plugin::Authentication::Store::Minimal::Backend;
458 # Sets up the user `test_user' with password `test_pass'
459 MyApp->default_auth_store(
460 Catalyst::Plugin::Authentication::Store::Minimal::Backend->new({
461 test_user => { password => 'test_pass' },
465 Now, your test code can call C<$c->login('test_user', 'test_pass')> and
466 successfully login, without messing with the database at all.
468 =head3 More information
470 L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authentication> has a longer explanation.
476 Authorization is the step that comes after
477 authentication. Authentication establishes that the user agent is
478 really representing the user we think it's representing, and then
479 authorization determines what this user is allowed to do.
481 =head3 Role Based Access Control
483 Under role based access control each user is allowed to perform any
484 number of roles. For example, at a zoo no one but specially trained
485 personnel can enter the moose cage (Mynd you, møøse bites kan be
486 pretty nasti!). For example:
488 package Zoo::Controller::MooseCage;
490 sub feed_moose : Local {
491 my ( $self, $c ) = @_;
493 $c->model( "Moose" )->eat( $c->req->param("food") );
496 With this action, anyone can just come into the moose cage and feed
497 the moose, which is a very dangerous thing. We need to restrict this
498 action, so that only a qualified moose feeder can perform that action.
500 The Authorization::Roles plugin let's us perform role based access
501 control checks. Let's load it:
503 use parent qw/Catalyst/;
504 __PACKAGE__->setup(qw/
505 Authentication # yadda yadda
509 And now our action should look like this:
511 sub feed_moose : Local {
512 my ( $self, $c ) = @_;
514 if ( $c->check_roles( "moose_feeder" ) ) {
515 $c->model( "Moose" )->eat( $c->req->param("food") );
517 $c->stash->{error} = "unauthorized";
521 This checks C<< $c->user >>, and only if the user has B<all> the roles
522 in the list, a true value is returned.
524 C<check_roles> has a sister method, C<assert_roles>, which throws an
525 exception if any roles are missing.
527 Some roles that might actually make sense in, say, a forum application:
541 each with a distinct task (system administration versus content
544 =head3 Access Control Lists
546 Checking for roles all the time can be tedious and error prone.
548 The Authorization::ACL plugin let's us declare where we'd like checks
549 to be done automatically for us.
551 For example, we may want to completely block out anyone who isn't a
552 C<moose_feeder> from the entire C<MooseCage> controller:
554 Zoo->deny_access_unless( "/moose_cage", [qw/moose_feeder/] );
556 The role list behaves in the same way as C<check_roles>. However, the
557 ACL plugin isn't limited to just interacting with the Roles plugin. We
558 can use a code reference instead. For example, to allow either moose
559 trainers or moose feeders into the moose cage, we can create a more
562 Zoo->deny_access_unless( "/moose_cage", sub {
564 $c->check_roles( "moose_trainer" ) || $c->check_roles( "moose_feeder" );
567 The more specific a role, the earlier it will be checked. Let's say
568 moose feeders are now restricted to only the C<feed_moose> action,
569 while moose trainers get access everywhere:
571 Zoo->deny_access_unless( "/moose_cage", [qw/moose_trainer/] );
572 Zoo->allow_access_if( "/moose_cage/feed_moose", [qw/moose_feeder/]);
574 When the C<feed_moose> action is accessed the second check will be
575 made. If the user is a C<moose_feeder>, then access will be
576 immediately granted. Otherwise, the next rule in line will be tested -
577 the one checking for a C<moose_trainer>. If this rule is not
578 satisfied, access will be immediately denied.
580 Rules applied to the same path will be checked in the order they were
583 Lastly, handling access denial events is done by creating an
584 C<access_denied> private action:
586 sub access_denied : Private {
587 my ( $self, $c, $action ) = @_;
590 This action works much like auto, in that it is inherited across
591 namespaces (not like object oriented code). This means that the
592 C<access_denied> action which is B<nearest> to the action which was
593 blocked will be triggered.
595 If this action does not exist, an error will be thrown, which you can
596 clean up in your C<end> private action instead.
598 Also, it's important to note that if you restrict access to "/" then
599 C<end>, C<default>, etc will also be restricted.
601 MyApp->acl_allow_root_internals;
603 will create rules that permit access to C<end>, C<begin>, and C<auto> in the
604 root of your app (but not in any other controller).
608 Models are where application data belongs. Catalyst is exteremely
609 flexible with the kind of models that it can use. The recipes here
612 =head2 Using existing DBIC (etc.) classes with Catalyst
614 Many people have existing Model classes that they would like to use
615 with Catalyst (or, conversely, they want to write Catalyst models that
616 can be used outside of Catalyst, e.g. in a cron job). It's trivial to
617 write a simple component in Catalyst that slurps in an outside Model:
619 package MyApp::Model::DB;
620 use base qw/Catalyst::Model::DBIC::Schema/;
622 schema_class => 'Some::DBIC::Schema',
623 connect_info => ['dbi:SQLite:foo.db', '', '', {AutoCommit=>1}];
627 and that's it! Now C<Some::DBIC::Schema> is part of your
628 Cat app as C<MyApp::Model::DB>.
630 =head2 DBIx::Class as a Catalyst Model
632 See L<Catalyst::Model::DBIC::Schema>.
634 =head2 Create accessors to preload static data once per server instance
636 When you have data that you want to load just once from the model at
637 server load instead of for each request, use mk_group_accessors to
638 create accessors and tie them to resultsets in your package that
639 inherits from DBIx::Class::Schema
642 use base qw/DBIx::Class::Schema/;
643 __PACKAGE__->register_class('RESULTSOURCEMONIKER',
644 'My::Schema::RESULTSOURCE');
645 __PACKAGE__->mk_group_accessors('simple' =>
646 qw(ACCESSORNAME1 ACCESSORNAME2 ACCESSORNAMEn));
649 my ($self, @rest) = @_;
650 $self->next::method(@rest);
651 # $self is now a live My::Schema object, complete with DB connection
653 $self->ACCESSORNAME1([ $self->resultset('RESULTSOURCEMONIKER')->all ]);
654 $self->ACCESSORNAME2([ $self->resultset('RESULTSOURCEMONIKER')->search({ COLUMN => { '<' => '30' } })->all ]);
655 $self->ACCESSORNAMEn([ $self->resultset('RESULTSOURCEMONIKER')->find(1) ]);
660 and now in the controller, you can now access any of these without a
663 $c->stash->{something} = $c->model('My::Schema')->schema->ACCESSORNAMEn;
668 Unlike SOAP, XMLRPC is a very simple (and imo elegant) web-services
669 protocol, exchanging small XML messages like these:
674 TE: deflate,gzip;q=0.3
675 Connection: TE, close
679 User-Agent: SOAP::Lite/Perl/0.60
681 Content-Type: text/xml
683 <?xml version="1.0" encoding="UTF-8"?>
685 <methodName>add</methodName>
687 <param><value><int>1</int></value></param>
688 <param><value><int>2</int></value></param>
695 Date: Tue, 20 Dec 2005 07:45:55 GMT
697 Content-Type: text/xml
701 <?xml version="1.0" encoding="us-ascii"?>
704 <param><value><int>3</int></value></param>
708 Now follow these few steps to implement the application:
710 1. Install Catalyst (5.61 or later), Catalyst::Plugin::XMLRPC (0.06 or
711 later) and SOAP::Lite (for XMLRPCsh.pl).
713 2. Create an application framework:
719 3. Add the XMLRPC plugin to MyApp.pm
721 __PACKAGE__->setup( qw/-Debug Static::Simple XMLRPC/);
723 4. Add an API controller
725 % ./script/myapp_create.pl controller API
727 5. Add a XMLRPC redispatch method and an add method with Remote
728 attribute to lib/MyApp/Controller/API.pm
731 my ( $self, $c ) = @_;
736 my ( $self, $c, $a, $b ) = @_;
740 The default action is the entry point for each XMLRPC request. It will
741 redispatch every request to methods with Remote attribute in the same
744 The C<add> method is not a traditional action; it has no private or
745 public path. Only the XMLRPC dispatcher knows it exists.
747 6. That's it! You have built your first web service. Let's test it with
748 XMLRPCsh.pl (part of SOAP::Lite):
750 % ./script/myapp_server.pl
752 % XMLRPCsh.pl http://127.0.0.1:3000/api
753 Usage: method[(parameters)]
755 --- XMLRPC RESULT ---
760 Your return data type is usually auto-detected, but you can easily
761 enforce a specific one.
764 my ( $self, $c, $a, $b ) = @_;
765 return RPC::XML::int->new( $a + $b );
772 Views pertain to the display of your application. As with models,
773 catalyst is uncommonly flexible. The recipes below are just a start.
775 =head2 Catalyst::View::TT
777 One of the first things you probably want to do when starting a new
778 Catalyst application is set up your View. Catalyst doesn't care how you
779 display your data; you can choose to generate HTML, PDF files, or plain
782 Most Catalyst applications use a template system to generate their HTML,
783 and though there are several template systems available, Template
784 Toolkit is probably the most popular.
786 Once again, the Catalyst developers have done all the hard work, and
787 made things easy for the rest of us. Catalyst::View::TT provides the
788 interface to Template Toolkit, and provides Helpers which let us set it
789 up that much more easily.
791 =head3 Creating your View
793 Catalyst::View::TT provides two different helpers for us to use: TT and
798 Create a basic Template Toolkit View using the provided helper script:
800 script/myapp_create.pl view TT TT
802 This will create lib/MyApp/View/MyView.pm, which is going to be pretty
803 empty to start. However, it sets everything up that you need to get
804 started. You can now define which template you want and forward to your
808 my ( $self, $c ) = @_;
810 $c->stash->{template} = 'hello.tt';
812 $c->forward( $c->view('TT') );
815 In practice you wouldn't do the forwarding manually, but would
816 use L<Catalyst::Action::RenderView>.
820 Although the TT helper does create a functional, working view, you may
821 find yourself having to create the same template files and changing the
822 same options every time you create a new application. The TTSite helper
823 saves us even more time by creating the basic templates and setting some
824 common options for us.
826 Once again, you can use the helper script:
828 script/myapp_create.pl view TT TTSite
830 This time, the helper sets several options for us in the generated View.
832 __PACKAGE__->config({
833 CATALYST_VAR => 'Catalyst',
835 MyApp->path_to( 'root', 'src' ),
836 MyApp->path_to( 'root', 'lib' )
838 PRE_PROCESS => 'config/main',
839 WRAPPER => 'site/wrapper',
840 ERROR => 'error.tt2',
848 INCLUDE_PATH defines the directories that Template Toolkit should search
849 for the template files.
853 PRE_PROCESS is used to process configuration options which are common to
858 WRAPPER is a file which is processed with each template, usually used to
859 easily provide a common header and footer for every page.
863 In addition to setting these options, the TTSite helper also created the
864 template and config files for us! In the 'root' directory, you'll notice
865 two new directories: src and lib.
867 Several configuration files in root/lib/config are called by PRE_PROCESS.
869 The files in root/lib/site are the site-wide templates, called by
870 WRAPPER, and display the html framework, control the layout, and provide
871 the templates for the header and footer of your page. Using the template
872 organization provided makes it much easier to standardize pages and make
873 changes when they are (inevitably) needed.
875 The template files that you will create for your application will go
876 into root/src, and you don't need to worry about putting the the <html>
877 or <head> sections; just put in the content. The WRAPPER will the rest
878 of the page around your template for you.
883 Of course, having the template system include the header and footer for
884 you isn't all that we want our templates to do. We need to be able to
885 put data into our templates, and have it appear where and how we want
886 it, right? That's where the stash comes in.
888 In our controllers, we can add data to the stash, and then access it
889 from the template. For instance:
892 my ( $self, $c ) = @_;
894 $c->stash->{name} = 'Adam';
896 $c->stash->{template} = 'hello.tt';
898 $c->forward( $c->view('TT') );
903 <strong>Hello, [% name %]!</strong>
905 When you view this page, it will display "Hello, Adam!"
907 All of the information in your stash is available, by its name/key, in
908 your templates. And your data don't have to be plain, old, boring
909 scalars. You can pass array references and hash references, too.
914 my ( $self, $c ) = @_;
916 $c->stash->{names} = [ 'Adam', 'Dave', 'John' ];
918 $c->stash->{template} = 'hello.tt';
920 $c->forward( $c->view('TT') );
925 [% FOREACH name IN names %]
926 <strong>Hello, [% name %]!</strong><br />
929 This allowed us to loop through each item in the arrayref, and display a
930 line for each name that we have.
932 This is the most basic usage, but Template Toolkit is quite powerful,
933 and allows you to truly keep your presentation logic separate from the
934 rest of your application.
938 One of my favorite things about Catalyst is the ability to move an
939 application around without having to worry that everything is going to
940 break. One of the areas that used to be a problem was with the http
941 links in your template files. For example, suppose you have an
942 application installed at http://www.domain.com/Calendar. The links point
943 to "/Calendar", "/Calendar/2005", "/Calendar/2005/10", etc. If you move
944 the application to be at http://www.mydomain.com/Tools/Calendar, then
945 all of those links will suddenly break.
947 That's where $c->uri_for() comes in. This function will merge its
948 parameters with either the base location for the app, or its current
949 namespace. Let's take a look at a couple of examples.
951 In your template, you can use the following:
953 <a href="[% c.uri_for('/login') %]">Login Here</a>
955 Although the parameter starts with a forward slash, this is relative
956 to the application root, not the webserver root. This is important to
957 remember. So, if your application is installed at
958 http://www.domain.com/Calendar, then the link would be
959 http://www.mydomain.com/Calendar/Login. If you move your application
960 to a different domain or path, then that link will still be correct.
964 <a href="[% c.uri_for('2005','10', '24') %]">October, 24 2005</a>
966 The first parameter does NOT have a forward slash, and so it will be
967 relative to the current namespace. If the application is installed at
968 http://www.domain.com/Calendar. and if the template is called from
969 MyApp::Controller::Display, then the link would become
970 http://www.domain.com/Calendar/Display/2005/10/24.
972 If you want to link to a parent uri of your current namespace you can
973 prefix the arguments with multiple '../':
975 <a href="[% c.uri_for('../../view', stashed_object.id) %]">User view</a>
977 Once again, this allows you to move your application around without
978 having to worry about broken links. But there's something else, as
979 well. Since the links are generated by uri_for, you can use the same
980 template file by several different controllers, and each controller
981 will get the links that its supposed to. Since we believe in Don't
982 Repeat Yourself, this is particularly helpful if you have common
983 elements in your site that you want to keep in one file.
987 L<http://search.cpan.org/perldoc?Catalyst>
989 L<http://search.cpan.org/perldoc?Catalyst%3A%3AView%3A%3ATT>
991 L<http://search.cpan.org/perldoc?Template>
993 =head2 Adding RSS feeds
995 Adding RSS feeds to your Catalyst applications is simple. We'll see two
996 different aproaches here, but the basic premise is that you forward to
997 the normal view action first to get the objects, then handle the output
1000 =head3 Using TT templates
1002 This is the aproach used in Agave (L<http://dev.rawmode.org/>).
1006 $c->forward('view');
1007 $c->stash->{template}='rss.tt';
1010 Then you need a template. Here's the one from Agave:
1012 <?xml version="1.0" encoding="UTF-8"?>
1013 <rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/">
1015 <title>[ [% blog.name || c.config.name || "Agave" %] ] RSS Feed</title>
1016 <link>[% base %]</link>
1017 <description>Recent posts</description>
1018 <language>en-us</language>
1020 [% WHILE (post = posts.next) %]
1022 <title>[% post.title %]</title>
1023 <description>[% post.formatted_teaser|html%]</description>
1024 <pubDate>[% post.pub_date %]</pubDate>
1025 <guid>[% post.full_uri %]</guid>
1026 <link>[% post.full_uri %]</link>
1027 <dc:creator>[% post.author.screenname %]</dc:creator>
1033 =head3 Using XML::Feed
1035 A more robust solution is to use XML::Feed, as was done in the Catalyst
1036 Advent Calendar. Assuming we have a C<view> action that populates
1037 'entries' with some DBIx::Class iterator, the code would look something
1042 $c->forward('view'); # get the entries
1044 my $feed = XML::Feed->new('RSS');
1045 $feed->title( $c->config->{name} . ' RSS Feed' );
1046 $feed->link( $c->req->base ); # link to the site.
1047 $feed->description('Catalyst advent calendar'); Some description
1049 # Process the entries
1050 while( my $entry = $c->stash->{entries}->next ) {
1051 my $feed_entry = XML::Feed::Entry->new('RSS');
1052 $feed_entry->title($entry->title);
1053 $feed_entry->link( $c->uri_for($entry->link) );
1054 $feed_entry->issued( DateTime->from_epoch(epoch => $entry->created) );
1055 $feed->add_entry($feed_entry);
1057 $c->res->body( $feed->as_xml );
1060 A little more code in the controller, but with this approach you're
1061 pretty sure to get something that validates.
1063 Note that for both of the above aproaches, you'll need to set the
1064 content type like this:
1066 $c->res->content_type('application/rss+xml');
1070 You could generalize the second variant easily by replacing 'RSS' with a
1071 variable, so you can generate Atom feeds with the same code.
1073 Now, go ahead and make RSS feeds for all your stuff. The world *needs*
1074 updates on your goldfish!
1076 =head2 Forcing the browser to download content
1078 Sometimes you need your application to send content for download. For
1079 example, you can generate a comma-separated values (CSV) file for your
1080 users to download and import into their spreadsheet program.
1082 Let's say you have an C<Orders> controller which generates a CSV file
1083 in the C<export> action (i.e., C<http://localhost:3000/orders/export>):
1085 sub export : Local Args(0) {
1086 my ( $self, $c ) = @_;
1088 # In a real application, you'd generate this from the database
1089 my $csv = "1,5.99\n2,29.99\n3,3.99\n";
1091 $c->res->content_type('text/comma-separated-values');
1092 $c->res->body($csv);
1095 Normally the browser uses the last part of the URI to generate a
1096 filename for data it cannot display. In this case your browser would
1097 likely ask you to save a file named C<export>.
1099 Luckily you can have the browser download the content with a specific
1100 filename by setting the C<Content-Disposition> header:
1102 my $filename = 'Important Orders.csv';
1103 $c->res->header('Content-Disposition', qq[attachment; filename="$filename"]);
1105 Note the use of quotes around the filename; this ensures that any
1106 spaces in the filename are handled by the browser.
1108 Put this right before calling C<< $c->res->body >> and your browser
1109 will download a file named C<Important Orders.csv> instead of
1112 You can also use this to have the browser download content which it
1113 normally displays, such as JPEG images or even HTML. Just be sure to
1114 set the appropriate content type and disposition.
1119 Controllers are the main point of communication between the web server
1120 and your application. Here we explore some aspects of how they work.
1122 =head2 Extending RenderView (formerly DefaultEnd)
1124 The recommended approach for an C<end> action is to use
1125 L<Catalyst::Action::RenderView> (taking the place of
1126 L<Catalyst::Plugin::DefaultEnd>), which does what you usually need.
1127 However there are times when you need to add a bit to it, but don't want
1128 to write your own C<end> action.
1130 You can extend it like this:
1132 To add something to an C<end> action that is called before rendering
1133 (this is likely to be what you want), simply place it in the C<end>
1136 sub end : ActionClass('RenderView') {
1137 my ( $self, $c ) = @_;
1138 # do stuff here; the RenderView action is called afterwards
1141 To add things to an C<end> action that are called I<after> rendering,
1142 you can set it up like this:
1144 sub render : ActionClass('RenderView') { }
1147 my ( $self, $c ) = @_;
1148 $c->forward('render');
1156 A Catalyst application is driven by one or more Controller
1157 modules. There are a number of ways that Catalyst can decide which of
1158 the methods in your controller modules it should call. Controller
1159 methods are also called actions, because they determine how your
1160 catalyst application should (re-)act to any given URL. When the
1161 application is started up, catalyst looks at all your actions, and
1162 decides which URLs they map to.
1164 =head3 Type attributes
1166 Each action is a normal method in your controller, except that it has an
1167 L<attribute|http://search.cpan.org/~nwclark/perl-5.8.7/lib/attributes.pm>
1168 attached. These can be one of several types.
1170 Assume our Controller module starts with the following package declaration:
1172 package MyApp::Controller::Buckets;
1174 and we are running our application on localhost, port 3000 (the test
1181 A Path attribute also takes an argument, this can be either a relative
1182 or an absolute path. A relative path will be relative to the
1183 controller namespace, an absolute path will represent an exact
1186 sub my_handles : Path('handles') { .. }
1190 http://localhost:3000/buckets/handles
1194 sub my_handles : Path('/handles') { .. }
1198 http://localhost:3000/handles
1202 When using a Local attribute, no parameters are needed, instead, the
1203 name of the action is matched in the URL. The namespaces created by
1204 the name of the controller package is always part of the URL.
1206 sub my_handles : Local { .. }
1210 http://localhost:3000/buckets/my_handles
1214 A Global attribute is similar to a Local attribute, except that the
1215 namespace of the controller is ignored, and matching starts at root.
1217 sub my_handles : Global { .. }
1221 http://localhost:3000/my_handles
1225 By now you should have figured that a Regex attribute is just what it
1226 sounds like. This one takes a regular expression, and matches starting
1227 from root. These differ from the rest as they can match multiple URLs.
1229 sub my_handles : Regex('^handles') { .. }
1233 http://localhost:3000/handles
1237 http://localhost:3000/handles_and_other_parts
1243 A LocalRegex is similar to a Regex, except it only matches below the current
1244 controller namespace.
1246 sub my_handles : LocalRegex(^handles') { .. }
1250 http://localhost:3000/buckets/handles
1254 http://localhost:3000/buckets/handles_and_other_parts
1260 Last but not least, there is the Private attribute, which allows you
1261 to create your own internal actions, which can be forwarded to, but
1262 won't be matched as URLs.
1264 sub my_handles : Private { .. }
1266 becomes nothing at all..
1268 Catalyst also predefines some special Private actions, which you can
1269 override, these are:
1275 The default action will be called, if no other matching action is
1276 found. If you don't have one of these in your namespace, or any sub
1277 part of your namespace, you'll get an error page instead. If you want
1278 to find out where it was the user was trying to go, you can look in
1279 the request object using C<< $c->req->path >>.
1281 sub default :Path { .. }
1283 works for all unknown URLs, in this controller namespace, or every one
1284 if put directly into MyApp.pm.
1288 The index action is called when someone tries to visit the exact
1289 namespace of your controller. If index, default and matching Path
1290 actions are defined, then index will be used instead of default and
1293 sub index :Path :Args(0) { .. }
1297 http://localhost:3000/buckets
1301 The begin action is called at the beginning of every request involving
1302 this namespace directly, before other matching actions are called. It
1303 can be used to set up variables/data for this particular part of your
1304 app. A single begin action is called, its always the one most relevant
1305 to the current namespace.
1307 sub begin : Private { .. }
1311 http://localhost:3000/bucket/(anything)?
1317 Like begin, this action is always called for the namespace it is in,
1318 after every other action has finished. It is commonly used to forward
1319 processing to the View component. A single end action is called, its
1320 always the one most relevant to the current namespace.
1323 sub end : Private { .. }
1325 is called once after any actions when
1327 http://localhost:3000/bucket/(anything)?
1333 Lastly, the auto action is magic in that B<every> auto action in the
1334 chain of paths up to and including the ending namespace, will be
1335 called. (In contrast, only one of the begin/end/default actions will
1336 be called, the relevant one).
1339 sub auto : Private { .. }
1343 sub auto : Private { .. }
1345 will both be called when visiting
1347 http://localhost:3000/bucket/(anything)?
1353 =head3 A word of warning
1355 Due to possible namespace conflicts with Plugins, it is advised to
1356 only put the pre-defined Private actions in your main MyApp.pm file,
1357 all others should go in a Controller module.
1359 =head3 More Information
1361 L<http://search.cpan.org/author/SRI/Catalyst-5.61/lib/Catalyst/Manual/Intro.pod>
1363 L<http://dev.catalyst.perl.org/wiki/FlowChart>
1365 =head2 Component-based Subrequests
1367 See L<Catalyst::Plugin::SubRequest>.
1371 =head3 Single file upload with Catalyst
1373 To implement uploads in Catalyst, you need to have a HTML form similar to
1376 <form action="/upload" method="post" enctype="multipart/form-data">
1377 <input type="hidden" name="form_submit" value="yes">
1378 <input type="file" name="my_file">
1379 <input type="submit" value="Send">
1382 It's very important not to forget C<enctype="multipart/form-data"> in
1385 Catalyst Controller module 'upload' action:
1387 sub upload : Global {
1388 my ($self, $c) = @_;
1390 if ( $c->request->parameters->{form_submit} eq 'yes' ) {
1392 if ( my $upload = $c->request->upload('my_file') ) {
1394 my $filename = $upload->filename;
1395 my $target = "/tmp/upload/$filename";
1397 unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
1398 die( "Failed to copy '$filename' to '$target': $!" );
1403 $c->stash->{template} = 'file_upload.html';
1406 =head3 Multiple file upload with Catalyst
1408 Code for uploading multiple files from one form needs a few changes:
1410 The form should have this basic structure:
1412 <form action="/upload" method="post" enctype="multipart/form-data">
1413 <input type="hidden" name="form_submit" value="yes">
1414 <input type="file" name="file1" size="50"><br>
1415 <input type="file" name="file2" size="50"><br>
1416 <input type="file" name="file3" size="50"><br>
1417 <input type="submit" value="Send">
1420 And in the controller:
1422 sub upload : Local {
1423 my ($self, $c) = @_;
1425 if ( $c->request->parameters->{form_submit} eq 'yes' ) {
1427 for my $field ( $c->req->upload ) {
1429 my $upload = $c->req->upload($field);
1430 my $filename = $upload->filename;
1431 my $target = "/tmp/upload/$filename";
1433 unless ( $upload->link_to($target) || $upload->copy_to($target) ) {
1434 die( "Failed to copy '$filename' to '$target': $!" );
1439 $c->stash->{template} = 'file_upload.html';
1442 C<for my $field ($c-E<gt>req->upload)> loops automatically over all file
1443 input fields and gets input names. After that is basic file saving code,
1444 just like in single file upload.
1446 Notice: C<die>ing might not be what you want to do, when an error
1447 occurs, but it works as an example. A better idea would be to store
1448 error C<$!> in $c->stash->{error} and show a custom error template
1449 displaying this message.
1451 For more information about uploads and usable methods look at
1452 L<Catalyst::Request::Upload> and L<Catalyst::Request>.
1454 =head2 Forwarding with arguments
1456 Sometimes you want to pass along arguments when forwarding to another
1457 action. As of version 5.30, arguments can be passed in the call to
1458 C<forward>; in earlier versions, you can manually set the arguments in
1459 the Catalyst Request object:
1461 # version 5.30 and later:
1462 $c->forward('/wherever', [qw/arg1 arg2 arg3/]);
1465 $c->req->args([qw/arg1 arg2 arg3/]);
1466 $c->forward('/wherever');
1468 (See the L<Catalyst::Manual::Intro> Flow_Control section for more
1469 information on passing arguments via C<forward>.)
1474 The recipes below describe aspects of the deployment process,
1475 including web server engines and tips to improve application efficiency.
1477 =head2 mod_perl Deployment
1479 mod_perl is the best solution for many applications, but we'll list some pros
1480 and cons so you can decide for yourself. The other production deployment
1481 option is FastCGI, for which see below.
1487 mod_perl is very fast and your app will benefit from being loaded in memory
1488 within each Apache process.
1490 =head4 Shared memory for multiple apps
1492 If you need to run several Catalyst apps on the same server, mod_perl will
1493 share the memory for common modules.
1499 Since your application is fully loaded in memory, every Apache process will
1500 be rather large. This means a large Apache process will be tied up while
1501 serving static files, large files, or dealing with slow clients. For this
1502 reason, it is best to run a two-tiered web architecture with a lightweight
1503 frontend server passing dynamic requests to a large backend mod_perl
1508 Any changes made to the core code of your app require a full Apache restart.
1509 Catalyst does not support Apache::Reload or StatINC. This is another good
1510 reason to run a frontend web server where you can set up an
1511 C<ErrorDocument 502> page to report that your app is down for maintenance.
1513 =head4 Cannot run multiple versions of the same app
1515 It is not possible to run two different versions of the same application in
1516 the same Apache instance because the namespaces will collide.
1520 Now that we have that out of the way, let's talk about setting up mod_perl
1521 to run a Catalyst app.
1523 =head4 1. Install Catalyst::Engine::Apache
1525 You should install the latest versions of both Catalyst and
1526 Catalyst::Engine::Apache. The Apache engines were separated from the
1527 Catalyst core in version 5.50 to allow for updates to the engine without
1528 requiring a new Catalyst release.
1530 =head4 2. Install Apache with mod_perl
1532 Both Apache 1.3 and Apache 2 are supported, although Apache 2 is highly
1533 recommended. With Apache 2, make sure you are using the prefork MPM and not
1534 the worker MPM. The reason for this is that many Perl modules are not
1535 thread-safe and may have problems running within the threaded worker
1536 environment. Catalyst is thread-safe however, so if you know what you're
1537 doing, you may be able to run using worker.
1539 In Debian, the following commands should get you going.
1541 apt-get install apache2-mpm-prefork
1542 apt-get install libapache2-mod-perl2
1544 =head4 3. Configure your application
1546 Every Catalyst application will automagically become a mod_perl handler
1547 when run within mod_perl. This makes the configuration extremely easy.
1548 Here is a basic Apache 2 configuration.
1550 PerlSwitches -I/var/www/MyApp/lib
1555 PerlResponseHandler MyApp
1558 The most important line here is C<PerlModule MyApp>. This causes mod_perl
1559 to preload your entire application into shared memory, including all of your
1560 controller, model, and view classes and configuration. If you have -Debug
1561 mode enabled, you will see the startup output scroll by when you first
1564 For an example Apache 1.3 configuration, please see the documentation for
1565 L<Catalyst::Engine::Apache::MP13>.
1569 That's it, your app is now a full-fledged mod_perl application! Try it out
1570 by going to http://your.server.com/.
1572 =head3 Other Options
1574 =head4 Non-root location
1576 You may not always want to run your app at the root of your server or virtual
1577 host. In this case, it's a simple change to run at any non-root location
1582 PerlResponseHandler MyApp
1585 When running this way, it is best to make use of the C<uri_for> method in
1586 Catalyst for constructing correct links.
1588 =head4 Static file handling
1590 Static files can be served directly by Apache for a performance boost.
1592 DocumentRoot /var/www/MyApp/root
1594 SetHandler default-handler
1597 This will let all files within root/static be handled directly by Apache. In
1598 a two-tiered setup, the frontend server should handle static files.
1599 The configuration to do this on the frontend will vary.
1601 The same is accomplished in lighttpd with the following snippet:
1603 $HTTP["url"] !~ "^/(?:img/|static/|css/|favicon.ico$)" {
1607 "socket" => "/tmp/myapp.socket",
1608 "check-local" => "disable",
1614 Which serves everything in the img, static, css directories
1615 statically, as well as the favicon file.
1617 Note the path of the application needs to be stated explicitly in the
1618 web server configuration for both these recipes.
1620 =head2 Catalyst on shared hosting
1622 So, you want to put your Catalyst app out there for the whole world to
1623 see, but you don't want to break the bank. There is an answer - if you
1624 can get shared hosting with FastCGI and a shell, you can install your
1625 Catalyst app in a local directory on your shared host. First, run
1627 perl -MCPAN -e shell
1629 and go through the standard CPAN configuration process. Then exit out
1630 without installing anything. Next, open your .bashrc and add
1632 export PATH=$HOME/local/bin:$HOME/local/script:$PATH
1633 perlversion=`perl -v | grep 'built for' | awk '{print $4}' | sed -e 's/v//;'`
1634 export PERL5LIB=$HOME/local/share/perl/$perlversion:$HOME/local/lib/perl/$perlversion:$HOME/local/lib:$PERL5LIB
1636 and log out, then back in again (or run C<". .bashrc"> if you
1637 prefer). Finally, edit C<.cpan/CPAN/MyConfig.pm> and add
1639 'make_install_arg' => qq[SITEPREFIX=$ENV{HOME}/local],
1640 'makepl_arg' => qq[INSTALLDIRS=site install_base=$ENV{HOME}/local],
1642 Now you can install the modules you need using CPAN as normal; they
1643 will be installed into your local directory, and perl will pick them
1644 up. Finally, change directory into the root of your virtual host and
1645 symlink your application's script directory in:
1647 cd path/to/mydomain.com
1648 ln -s ~/lib/MyApp/script script
1650 And add the following lines to your .htaccess file (assuming the server
1651 is setup to handle .pl as fcgi - you may need to rename the script to
1652 myapp_fastcgi.fcgi and/or use a SetHandler directive):
1655 RewriteCond %{REQUEST_URI} !^/?script/myapp_fastcgi.pl
1656 RewriteRule ^(.*)$ script/myapp_fastcgi.pl/$1 [PT,L]
1658 Now C<http://mydomain.com/> should now Just Work. Congratulations, now
1659 you can tell your friends about your new website (or in our case, tell
1660 the client it's time to pay the invoice :) )
1662 =head2 FastCGI Deployment
1664 FastCGI is a high-performance extension to CGI. It is suitable
1665 for production environments.
1671 FastCGI performs equally as well as mod_perl. Don't let the 'CGI' fool you;
1672 your app runs as multiple persistent processes ready to receive connections
1673 from the web server.
1677 When using external FastCGI servers, your application runs as a standalone
1678 application server. It may be restarted independently from the web server.
1679 This allows for a more robust environment and faster reload times when
1680 pushing new app changes. The frontend server can even be configured to
1681 display a friendly "down for maintenance" page while the application is
1684 =head4 Load-balancing
1686 You can launch your application on multiple backend servers and allow the
1687 frontend web server to load-balance between all of them. And of course, if
1688 one goes down, your app continues to run fine.
1690 =head4 Multiple versions of the same app
1692 Each FastCGI application is a separate process, so you can run different
1693 versions of the same app on a single server.
1695 =head4 Can run with threaded Apache
1697 Since your app is not running inside of Apache, the faster mpm_worker module
1698 can be used without worrying about the thread safety of your application.
1702 =head4 More complex environment
1704 With FastCGI, there are more things to monitor and more processes running
1705 than when using mod_perl.
1709 =head4 1. Install Apache with mod_fastcgi
1711 mod_fastcgi for Apache is a third party module, and can be found at
1712 L<http://www.fastcgi.com/>. It is also packaged in many distributions,
1713 for example, libapache2-mod-fastcgi in Debian.
1715 =head4 2. Configure your application
1717 # Serve static content directly
1718 DocumentRoot /var/www/MyApp/root
1719 Alias /static /var/www/MyApp/root/static
1721 FastCgiServer /var/www/MyApp/script/myapp_fastcgi.pl -processes 3
1722 Alias /myapp/ /var/www/MyApp/script/myapp_fastcgi.pl/
1724 # Or, run at the root
1725 Alias / /var/www/MyApp/script/myapp_fastcgi.pl/
1727 The above commands will launch 3 app processes and make the app available at
1730 =head3 Standalone server mode
1732 While not as easy as the previous method, running your app as an external
1733 server gives you much more flexibility.
1735 First, launch your app as a standalone server listening on a socket.
1737 script/myapp_fastcgi.pl -l /tmp/myapp.socket -n 5 -p /tmp/myapp.pid -d
1739 You can also listen on a TCP port if your web server is not on the same
1742 script/myapp_fastcgi.pl -l :8080 -n 5 -p /tmp/myapp.pid -d
1744 You will probably want to write an init script to handle starting/stopping
1745 of the app using the pid file.
1747 Now, we simply configure Apache to connect to the running server.
1749 # 502 is a Bad Gateway error, and will occur if the backend server is down
1750 # This allows us to display a friendly static page that says "down for
1752 Alias /_errors /var/www/MyApp/root/error-pages
1753 ErrorDocument 502 /_errors/502.html
1755 FastCgiExternalServer /tmp/myapp.fcgi -socket /tmp/myapp.socket
1756 Alias /myapp/ /tmp/myapp.fcgi/
1758 # Or, run at the root
1759 Alias / /tmp/myapp.fcgi/
1763 L<Catalyst::Engine::FastCGI>.
1765 =head2 Development server deployment
1767 The development server is a mini web server written in perl. If you
1768 expect a low number of hits or you don't need mod_perl/FastCGI speed,
1769 you could use the development server as the application server with a
1770 lightweight proxy web server at the front. However, consider using
1771 L<Catalyst::Engine::HTTP::POE> for this kind of deployment instead, since
1772 it can better handle multiple concurrent requests without forking, or can
1773 prefork a set number of servers for improved performance.
1777 As this is an application server setup, the pros are the same as
1778 FastCGI (with the exception of speed).
1783 The development server is what you create your code on, so if it works
1784 here, it should work in production!
1790 Not as fast as mod_perl or FastCGI. Needs to fork for each request
1791 that comes in - make sure static files are served by the web server to
1796 =head4 Start up the development server
1798 script/myapp_server.pl -p 8080 -k -f -pidfile=/tmp/myapp.pid
1800 You will probably want to write an init script to handle stop/starting
1801 the app using the pid file.
1803 =head4 Configuring Apache
1805 Make sure mod_proxy is enabled and add:
1807 # Serve static content directly
1808 DocumentRoot /var/www/MyApp/root
1809 Alias /static /var/www/MyApp/root/static
1816 ProxyPass / http://localhost:8080/
1817 ProxyPassReverse / http://localhost:8080/
1819 You can wrap the above within a VirtualHost container if you want
1820 different apps served on the same host.
1822 =head2 Quick deployment: Building PAR Packages
1824 You have an application running on your development box, but then you
1825 have to quickly move it to another one for
1826 demonstration/deployment/testing...
1828 PAR packages can save you from a lot of trouble here. They are usual Zip
1829 files that contain a blib tree; you can even include all prereqs and a
1830 perl interpreter by setting a few flags!
1832 =head3 Follow these few points to try it out!
1834 1. Install Catalyst and PAR 0.89 (or later)
1836 % perl -MCPAN -e 'install Catalyst'
1838 % perl -MCPAN -e 'install PAR'
1841 2. Create a application
1847 Recent versions of Catalyst (5.62 and up) include
1848 L<Module::Install::Catalyst>, which simplifies the process greatly. From the shell in your application directory:
1853 Congratulations! Your package "myapp.par" is ready, the following
1854 steps are just optional.
1856 3. Test your PAR package with "parl" (no typo)
1860 [parl] myapp[.par] [script] [arguments]
1863 parl myapp.par myapp_server.pl -r
1873 % parl myapp.par myapp_server.pl
1874 You can connect to your server at http://localhost:3000
1876 Yes, this nifty little starter application gets automatically included.
1877 You can also use "catalyst_par_script('myapp_server.pl')" to set a
1878 default script to execute.
1880 6. Want to create a binary that includes the Perl interpreter?
1882 % pp -o myapp myapp.par
1883 % ./myapp myapp_server.pl
1884 You can connect to your server at http://localhost:3000
1886 =head2 Serving static content
1888 Serving static content in Catalyst used to be somewhat tricky; the use
1889 of L<Catalyst::Plugin::Static::Simple> makes everything much easier.
1890 This plugin will automatically serve your static content during development,
1891 but allows you to easily switch to Apache (or other server) in a
1892 production environment.
1894 =head3 Introduction to Static::Simple
1896 Static::Simple is a plugin that will help to serve static content for your
1897 application. By default, it will serve most types of files, excluding some
1898 standard Template Toolkit extensions, out of your B<root> file directory. All
1899 files are served by path, so if B<images/me.jpg> is requested, then
1900 B<root/images/me.jpg> is found and served.
1904 Using the plugin is as simple as setting your use line in MyApp.pm to include:
1906 __PACKAGE__->setup( qw/Static::Simple/);
1908 and already files will be served.
1912 Static content is best served from a single directory within your root
1913 directory. Having many different directories such as C<root/css> and
1914 C<root/images> requires more code to manage, because you must separately
1915 identify each static directory--if you decide to add a C<root/js>
1916 directory, you'll need to change your code to account for it. In
1917 contrast, keeping all static directories as subdirectories of a main
1918 C<root/static> directory makes things much easier to manage. Here's an
1919 example of a typical root directory structure:
1923 root/controller/stuff.tt
1926 root/static/css/main.css
1927 root/static/images/logo.jpg
1928 root/static/js/code.js
1931 All static content lives under C<root/static>, with everything else being
1932 Template Toolkit files.
1938 You may of course want to change the default locations, and make
1939 Static::Simple look somewhere else, this is as easy as:
1941 MyApp->config->{static}->{include_path} = [
1942 MyApp->config->{root},
1946 When you override include_path, it will not automatically append the
1947 normal root path, so you need to add it yourself if you still want
1948 it. These will be searched in order given, and the first matching file
1951 =item Static directories
1953 If you want to force some directories to be only static, you can set
1954 them using paths relative to the root dir, or regular expressions:
1956 MyApp->config->{static}->{dirs} = [
1961 =item File extensions
1963 By default, the following extensions are not served (that is, they will
1964 be processed by Catalyst): B<tmpl, tt, tt2, html, xhtml>. This list can
1967 MyApp->config->{static}->{ignore_extensions} = [
1968 qw/tmpl tt tt2 html xhtml/
1971 =item Ignoring directories
1973 Entire directories can be ignored. If used with include_path,
1974 directories relative to the include_path dirs will also be ignored:
1976 MyApp->config->{static}->{ignore_dirs} = [ qw/tmpl css/ ];
1980 =head3 More information
1982 L<http://search.cpan.org/dist/Catalyst-Plugin-Static-Simple/>
1984 =head3 Serving manually with the Static plugin with HTTP::Daemon (myapp_server.pl)
1986 In some situations you might want to control things more directly,
1987 using L<Catalyst::Plugin::Static>.
1989 In your main application class (MyApp.pm), load the plugin:
1991 __PACKAGE__->setup( qw/-Debug FormValidator Static OtherPlugin/);
1993 You will also need to make sure your end method does I<not> forward
1994 static content to the view, perhaps like this:
1997 my ( $self, $c ) = @_;
1999 $c->forward( 'MyApp::View::TT' )
2000 unless ( $c->res->body || !$c->stash->{template} );
2003 This code will only forward to the view if a template has been
2004 previously defined by a controller and if there is not already data in
2005 C<$c-E<gt>res-E<gt>body>.
2007 Next, create a controller to handle requests for the /static path. Use
2008 the Helper to save time. This command will create a stub controller as
2009 C<lib/MyApp/Controller/Static.pm>.
2011 $ script/myapp_create.pl controller Static
2013 Edit the file and add the following methods:
2015 # serve all files under /static as static files
2016 sub default : Path('/static') {
2017 my ( $self, $c ) = @_;
2019 # Optional, allow the browser to cache the content
2020 $c->res->headers->header( 'Cache-Control' => 'max-age=86400' );
2022 $c->serve_static; # from Catalyst::Plugin::Static
2025 # also handle requests for /favicon.ico
2026 sub favicon : Path('/favicon.ico') {
2027 my ( $self, $c ) = @_;
2032 You can also define a different icon for the browser to use instead of
2033 favicon.ico by using this in your HTML header:
2035 <link rel="icon" href="/static/myapp.ico" type="image/x-icon" />
2037 =head3 Common problems with the Static plugin
2039 The Static plugin makes use of the C<shared-mime-info> package to
2040 automatically determine MIME types. This package is notoriously
2041 difficult to install, especially on win32 and OS X. For OS X the easiest
2042 path might be to install Fink, then use C<apt-get install
2043 shared-mime-info>. Restart the server, and everything should be fine.
2045 Make sure you are using the latest version (>= 0.16) for best
2046 results. If you are having errors serving CSS files, or if they get
2047 served as text/plain instead of text/css, you may have an outdated
2048 shared-mime-info version. You may also wish to simply use the following
2049 code in your Static controller:
2051 if ($c->req->path =~ /css$/i) {
2052 $c->serve_static( "text/css" );
2057 =head3 Serving Static Files with Apache
2059 When using Apache, you can bypass Catalyst and any Static
2060 plugins/controllers controller by intercepting requests for the
2061 C<root/static> path at the server level. All that is required is to
2062 define a DocumentRoot and add a separate Location block for your static
2063 content. Here is a complete config for this application under mod_perl
2067 use lib qw(/var/www/MyApp/lib);
2072 ServerName myapp.example.com
2073 DocumentRoot /var/www/MyApp/root
2075 SetHandler perl-script
2078 <LocationMatch "/(static|favicon.ico)">
2079 SetHandler default-handler
2083 And here's a simpler example that'll get you started:
2085 Alias /static/ "/my/static/files/"
2086 <Location "/static">
2092 Catalyst makes it easy to employ several different types of caching to
2093 speed up your applications.
2095 =head3 Cache Plugins
2097 There are three wrapper plugins around common CPAN cache modules:
2098 Cache::FastMmap, Cache::FileCache, and Cache::Memcached. These can be
2099 used to cache the result of slow operations.
2101 The Catalyst Advent Calendar uses the FileCache plugin to cache the
2102 rendered XHTML version of the source POD document. This is an ideal
2103 application for a cache because the source document changes
2104 infrequently but may be viewed many times.
2106 __PACKAGE__->setup( qw/Cache::FileCache/);
2111 sub render_pod : Local {
2112 my ( self, $c ) = @_;
2114 # the cache is keyed on the filename and the modification time
2115 # to check for updates to the file.
2116 my $file = $c->path_to( 'root', '2005', '11.pod' );
2117 my $mtime = ( stat $file )->mtime;
2119 my $cached_pod = $c->cache->get("$file $mtime");
2120 if ( !$cached_pod ) {
2121 $cached_pod = do_slow_pod_rendering();
2122 # cache the result for 12 hours
2123 $c->cache->set( "$file $mtime", $cached_pod, '12h' );
2125 $c->stash->{pod} = $cached_pod;
2128 We could actually cache the result forever, but using a value such as 12 hours
2129 allows old entries to be automatically expired when they are no longer needed.
2133 Another method of caching is to cache the entire HTML page. While this is
2134 traditionally handled by a front-end proxy server like Squid, the Catalyst
2135 PageCache plugin makes it trivial to cache the entire output from
2136 frequently-used or slow actions.
2138 Many sites have a busy content-filled front page that might look something
2139 like this. It probably takes a while to process, and will do the exact same
2140 thing for every single user who views the page.
2142 sub front_page : Path('/') {
2143 my ( $self, $c ) = @_;
2145 $c->forward( 'get_news_articles' );
2146 $c->forward( 'build_lots_of_boxes' );
2147 $c->forward( 'more_slow_stuff' );
2149 $c->stash->{template} = 'index.tt';
2152 We can add the PageCache plugin to speed things up.
2154 __PACKAGE__->setup( qw/Cache::FileCache PageCache/);
2156 sub front_page : Path ('/') {
2157 my ( $self, $c ) = @_;
2159 $c->cache_page( 300 );
2161 # same processing as above
2164 Now the entire output of the front page, from <html> to </html>, will be
2165 cached for 5 minutes. After 5 minutes, the next request will rebuild the
2166 page and it will be re-cached.
2168 Note that the page cache is keyed on the page URI plus all parameters, so
2169 requests for / and /?foo=bar will result in different cache items. Also,
2170 only GET requests will be cached by the plugin.
2172 You can even get that front-end Squid proxy to help out by enabling HTTP
2173 headers for the cached page.
2175 MyApp->config->{page_cache}->{set_http_headers} = 1;
2177 This would now set the following headers so proxies and browsers may cache
2178 the content themselves.
2180 Cache-Control: max-age=($expire_time - time)
2181 Expires: $expire_time
2182 Last-Modified: $cache_created_time
2184 =head3 Template Caching
2186 Template Toolkit provides support for caching compiled versions of your
2187 templates. To enable this in Catalyst, use the following configuration.
2188 TT will cache compiled templates keyed on the file mtime, so changes will
2189 still be automatically detected.
2191 package MyApp::View::TT;
2195 use base 'Catalyst::View::TT';
2197 __PACKAGE__->config(
2198 COMPILE_DIR => '/tmp/template_cache',
2205 See the documentation for each cache plugin for more details and other
2206 available configuration options.
2208 L<Catalyst::Plugin::Cache::FastMmap>
2209 L<Catalyst::Plugin::Cache::FileCache>
2210 L<Catalyst::Plugin::Cache::Memcached>
2211 L<Catalyst::Plugin::PageCache>
2212 L<http://search.cpan.org/dist/Template-Toolkit/lib/Template/Manual/Config.pod#Caching_and_Compiling_Options>
2216 Testing is an integral part of the web application development
2217 process. Tests make multi developer teams easier to coordinate, and
2218 they help ensure that there are no nasty surprises after upgrades or
2223 Catalyst provides a convenient way of testing your application during
2224 development and before deployment in a real environment.
2226 C<Catalyst::Test> makes it possible to run the same tests both locally
2227 (without an external daemon) and against a remote server via HTTP.
2231 Let's examine a skeleton application's C<t/> directory:
2233 mundus:~/MyApp chansen$ ls -l t/
2235 -rw-r--r-- 1 chansen chansen 95 18 Dec 20:50 01app.t
2236 -rw-r--r-- 1 chansen chansen 190 18 Dec 20:50 02pod.t
2237 -rw-r--r-- 1 chansen chansen 213 18 Dec 20:50 03podcoverage.t
2243 Verifies that the application loads, compiles, and returns a successful
2248 Verifies that all POD is free from errors. Only executed if the C<TEST_POD>
2249 environment variable is true.
2251 =item C<03podcoverage.t>
2253 Verifies that all methods/functions have POD coverage. Only executed if the
2254 C<TEST_POD> environment variable is true.
2258 =head3 Creating tests
2260 mundus:~/MyApp chansen$ cat t/01app.t | perl -ne 'printf( "%2d %s", $., $_ )'
2261 1 use Test::More tests => 2;
2262 2 use_ok( Catalyst::Test, 'MyApp' );
2264 4 ok( request('/')->is_success );
2266 The first line declares how many tests we are going to run, in this case
2267 two. The second line tests and loads our application in test mode. The
2268 fourth line verifies that our application returns a successful response.
2270 C<Catalyst::Test> exports two functions, C<request> and C<get>. Each can
2271 take three different arguments:
2275 =item A string which is a relative or absolute URI.
2277 request('/my/path');
2278 request('http://www.host.com/my/path');
2280 =item An instance of C<URI>.
2282 request( URI->new('http://www.host.com/my/path') );
2284 =item An instance of C<HTTP::Request>.
2286 request( HTTP::Request->new( GET => 'http://www.host.com/my/path') );
2290 C<request> returns an instance of C<HTTP::Response> and C<get> returns the
2291 content (body) of the response.
2293 =head3 Running tests locally
2295 mundus:~/MyApp chansen$ CATALYST_DEBUG=0 TEST_POD=1 prove --lib lib/ t/
2296 t/01app............ok
2297 t/02pod............ok
2298 t/03podcoverage....ok
2299 All tests successful.
2300 Files=3, Tests=4, 2 wallclock secs ( 1.60 cusr + 0.36 csys = 1.96 CPU)
2302 C<CATALYST_DEBUG=0> ensures that debugging is off; if it's enabled you
2303 will see debug logs between tests.
2305 C<TEST_POD=1> enables POD checking and coverage.
2307 C<prove> A command-line tool that makes it easy to run tests. You can
2308 find out more about it from the links below.
2310 =head3 Running tests remotely
2312 mundus:~/MyApp chansen$ CATALYST_SERVER=http://localhost:3000/ prove --lib lib/ t/01app.t
2314 All tests successful.
2315 Files=1, Tests=2, 0 wallclock secs ( 0.40 cusr + 0.01 csys = 0.41 CPU)
2317 C<CATALYST_SERVER=http://localhost:3000/> is the absolute deployment URI of
2318 your application. In C<CGI> or C<FastCGI> it should be the host and path
2321 =head3 C<Test::WWW::Mechanize> and Catalyst
2323 Be sure to check out C<Test::WWW::Mechanize::Catalyst>. It makes it easy to
2324 test HTML, forms and links. A short example of usage:
2326 use Test::More tests => 6;
2327 use_ok( Test::WWW::Mechanize::Catalyst, 'MyApp' );
2329 my $mech = Test::WWW::Mechanize::Catalyst->new;
2330 $mech->get_ok("http://localhost/", 'Got index page');
2331 $mech->title_like( qr/^MyApp on Catalyst/, 'Got right index title' );
2332 ok( $mech->find_link( text_regex => qr/^Wiki/i ), 'Found link to Wiki' );
2333 ok( $mech->find_link( text_regex => qr/^Mailing-List/i ), 'Found link to Mailing-List' );
2334 ok( $mech->find_link( text_regex => qr/^IRC channel/i ), 'Found link to IRC channel' );
2336 =head3 Further Reading
2340 =item Catalyst::Test
2342 L<http://search.cpan.org/dist/Catalyst/lib/Catalyst/Test.pm>
2344 =item Test::WWW::Mechanize::Catalyst
2346 L<http://search.cpan.org/dist/Test-WWW-Mechanize-Catalyst/lib/Test/WWW/Mechanize/Catalyst.pm>
2348 =item Test::WWW::Mechanize
2350 L<http://search.cpan.org/dist/Test-WWW-Mechanize/Mechanize.pm>
2352 =item WWW::Mechanize
2354 L<http://search.cpan.org/dist/WWW-Mechanize/lib/WWW/Mechanize.pm>
2356 =item LWP::UserAgent
2358 L<http://search.cpan.org/dist/libwww-perl/lib/LWP/UserAgent.pm>
2362 L<http://search.cpan.org/dist/libwww-perl/lib/HTML/Form.pm>
2366 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Message.pm>
2370 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request.pm>
2372 =item HTTP::Request::Common
2374 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Request/Common.pm>
2376 =item HTTP::Response
2378 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Response.pm>
2382 L<http://search.cpan.org/dist/libwww-perl/lib/HTTP/Status.pm>
2386 L<http://search.cpan.org/dist/URI/URI.pm>
2390 L<http://search.cpan.org/dist/Test-Simple/lib/Test/More.pm>
2394 L<http://search.cpan.org/dist/Test-Pod/Pod.pm>
2396 =item Test::Pod::Coverage
2398 L<http://search.cpan.org/dist/Test-Pod-Coverage/Coverage.pm>
2400 =item prove (Test::Harness)
2402 L<http://search.cpan.org/dist/Test-Harness/bin/prove>
2406 =head3 More Information
2408 L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authorization::Roles>
2409 L<http://search.cpan.org/perldoc?Catalyst::Plugin::Authorization::ACL>
2413 Sebastian Riedel C<sri@oook.de>
2415 Danijel Milicevic C<me@danijel.de>
2417 Viljo Marrandi C<vilts@yahoo.com>
2419 Marcus Ramberg C<mramberg@cpan.org>
2421 Jesse Sheidlower C<jester@panix.com>
2423 Andy Grundman C<andy@hybridized.org>
2425 Chisel Wright C<pause@herlpacker.co.uk>
2427 Will Hawes C<info@whawes.co.uk>
2429 Gavin Henry C<ghenry@perl.me.uk>
2431 Kieren Diment C<kd@totaldatasolution.com>
2435 This document is free, you can redistribute it and/or modify it
2436 under the same terms as Perl itself.