3 Catalyst::Manual::Tutorial::MoreCatalystBasics - Catalyst Tutorial - Part 3: More Catalyst Application Development Basics
8 This is B<Part 3 of 10> for the Catalyst tutorial.
10 L<Tutorial Overview|Catalyst::Manual::Tutorial>
16 L<Introduction|Catalyst::Manual::Tutorial::Intro>
20 L<Catalyst Basics|Catalyst::Manual::Tutorial::CatalystBasics>
24 B<More Catalyst Basics>
28 L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD>
32 L<Authentication|Catalyst::Manual::Tutorial::Authentication>
36 L<Authorization|Catalyst::Manual::Tutorial::Authorization>
40 L<Debugging|Catalyst::Manual::Tutorial::Debugging>
44 L<Testing|Catalyst::Manual::Tutorial::Testing>
48 L<Advanced CRUD|Catalyst::Manual::Tutorial::AdvancedCRUD>
52 L<Appendices|Catalyst::Manual::Tutorial::Appendices>
59 This part of the tutorial builds on the work done in Part 2 to explore
60 some features that are more typical of "real world" web applications.
61 From this part of the tutorial onward, we will be building a simple
62 book database application. Although the application will be too
63 limited to be of use to anyone, it should provide a basic environment
64 where we can explore a variety of features used in virtually all web
67 You can checkout the source code for this example from the catalyst
68 subversion repository as per the instructions in
69 L<Catalyst::Manual::Tutorial::Intro|Catalyst::Manual::Tutorial::Intro>.
72 =head1 CREATE A NEW APPLICATION
74 The remainder of the tutorial will build an application called C<MyApp>.
75 First use the Catalyst C<catalyst.pl> script to initialize the framework
76 for the C<MyApp> application (make sure you aren't still inside the
77 directory of the C<Hello> application from the previous part of the
82 created "MyApp/script"
86 created "MyApp/script/myapp_create.pl"
89 This creates a similar skeletal structure to what we saw in Part 2 of
90 the tutorial, except with C<MyApp> and C<myapp> substituted for
91 C<Hello> and C<hello>.
94 =head1 EDIT THE LIST OF CATALYST PLUGINS
96 One of the greatest benefits of Catalyst is that it has such a large
97 library of plugins and base classes available. Plugins are used to
98 seamlessly integrate existing Perl modules into the overall Catalyst
99 framework. In general, they do this by adding additional methods to the
100 C<context> object (generally written as C<$c>) that Catalyst passes to
101 every component throughout the framework.
103 By default, Catalyst enables three plugins/flags:
111 Enables the Catalyst debug output you saw when we started the
112 C<script/myapp_server.pl> development server earlier. You can remove
113 this item when you place your application into production.
115 As you may have noticed, C<-Debug> is not a plugin, but a I<flag>.
116 Although most of the items specified on the C<__PACKAGE__-E<gt>setup>
117 line of your application class will be plugins, Catalyst supports a
118 limited number of flag options (of these, C<-Debug> is the most
119 common). See the documentation for C<Catalyst.pm> to get details on
120 other flags (currently C<-Engine>, C<-Home>, and C<-Log>).
122 If you prefer, you can use the C<$c-E<gt>debug> method to enable debug
125 B<TIP>: Depending on your needs, it can be helpful to permanently
126 remove C<-Debug> from C<lib/MyApp.pm> and then use the C<-d> option
127 to C<script/myapp_server.pl> to re-enable it just for the development
128 server. We will not be using that approach in the tutorial, but feel
129 free to make use of it in your own projects.
133 L<Catalyst::Plugin::ConfigLoader|Catalyst::Plugin::ConfigLoader>
135 C<ConfigLoader> provides an automatic way to load configurable
136 parameters for your application from a central
137 L<Config::General|Config::General> file (versus having the values
138 hard-coded inside your Perl modules). Config::General uses syntax
139 very similar to Apache configuration files. We will see how to use
140 this feature of Catalyst during the authentication and authorization
141 sections (Part 5 and Part 6).
143 B<IMPORTANT NOTE:> If you are using a version of
144 L<Catalyst::Devel|Catalyst::Devel> prior to version 1.06, be aware
145 that Catalyst changed the default format from YAML to the more
146 straightforward C<Config::General> style. This tutorial uses the
147 newer C<myapp.conf> file for C<Config::General>. However, Catalyst
148 supports both formats and will automatically use either C<myapp.conf>
149 or C<myapp.yml> (or any other format supported by
150 L<Catalyst::Plugin::ConfigLoader|Catalyst::Plugin::ConfigLoader> and
151 L<Config::Any|Config::Any>). If you are using a version of
152 Catalyst::Devel prior to 1.06, you can convert to the newer format by
153 simply creating the C<myapp.conf> file manually and deleting
154 C<myapp.yml>. The default contents of the C<myapp.conf> you create
155 should only consist of one line:
159 B<TIP>: This script can be useful for converting between configuration
162 perl -Ilib -e 'use MyApp; use Config::General;
163 Config::General->new->save_file("myapp.conf", MyApp->config);'
167 L<Catalyst::Plugin::Static::Simple|Catalyst::Plugin::Static::Simple>
169 C<Static::Simple> provides an easy method of serving static content such
170 as images and CSS files under the development server.
174 For our application, we want to add one new plugin into the mix. To
175 do this, edit C<lib/MyApp.pm> (this file is generally referred to as
176 your I<application class>) and delete the line with:
178 __PACKAGE__->setup(qw/-Debug ConfigLoader Static::Simple/);
180 Then replace it with:
182 __PACKAGE__->setup(qw/
190 B<Note:> Recent versions of C<Catalyst::Devel> have used a variety of
191 techniques to load these plugins/flags. If you are following along in
192 Ubuntu 8.10, you should have C<Catalyst::Devel> v1.07 and see the
193 default code shown above. If you are using v1.08, you should see the
194 following by default:
196 use Catalyst qw/-Debug
200 __PACKAGE__->setup();
202 Don't let these variations confuse you -- they all accomplish the same
205 This tells Catalyst to start using one new plugin,
206 L<Catalyst::Plugin::StackTrace|Catalyst::Plugin::StackTrace>, to add a
207 stack trace to the standard Catalyst "debug screen" (the screen
208 Catalyst sends to your browser when an error occurs). Be aware that
209 L<StackTrace|Catalyst::Plugin::StackTrace> output appears in your
210 browser, not in the console window from which you're running your
211 application, which is where logging output usually goes.
219 C<__PACKAGE__> is just a shorthand way of referencing the name of the
220 package where it is used. Therefore, in C<MyApp.pm>, C<__PACKAGE__>
221 is equivalent to C<MyApp>.
225 You will want to disable L<StackTrace|Catalyst::Plugin::StackTrace>
226 before you put your application into production, but it can be helpful
231 When specifying plugins on the C<__PACKAGE__-E<gt>setup> line, you can
232 omit C<Catalyst::Plugin::> from the name. Additionally, you can
233 spread the plugin names across multiple lines as shown here, or place
234 them all on one (or more) lines as with the default configuration.
239 =head1 CREATE A CATALYST CONTROLLER
241 As discussed earlier, controllers are where you write methods that
242 interact with user input. Typically, controller methods respond to
243 C<GET> and C<POST> messages from the user's web browser.
245 Use the Catalyst C<create> script to add a controller for book-related
248 $ script/myapp_create.pl controller Books
249 exists "/home/me/MyApp/script/../lib/MyApp/Controller"
250 exists "/home/me/MyApp/script/../t"
251 created "/home/me/MyApp/script/../lib/MyApp/Controller/Books.pm"
252 created "/home/me/MyApp/script/../t/controller_Books.t"
254 Then edit C<lib/MyApp/Controller/Books.pm> (as discussed in Part 2 of
255 the Tutorial, Catalyst has a separate directory under C<lib/MyApp> for
256 each of the three parts of MVC: C<Model>, C<View>, and C<Controller>)
257 and add the following method to the controller:
261 Fetch all book objects and pass to books/list.tt2 in stash to be displayed
266 # Retrieve the usual Perl OO '$self' for this object. $c is the Catalyst
267 # 'Context' that's used to 'glue together' the various components
268 # that make up the application
271 # Retrieve all of the book records as book model objects and store in the
272 # stash where they can be accessed by the TT template
273 # $c->stash->{books} = [$c->model('DB::Books')->all];
274 # But, for now, use this code until we create the model later
275 $c->stash->{books} = '';
277 # Set the TT template to use. You will almost always want to do this
278 # in your action methods (action methods respond to user input in
280 $c->stash->{template} = 'books/list.tt2';
283 B<TIP>: See Appendix 1 for tips on removing the leading spaces when
284 cutting and pasting example code from POD-based documents.
286 Programmers experienced with object-oriented Perl should recognize
287 C<$self> as a reference to the object where this method was called.
288 On the other hand, C<$c> will be new to many Perl programmers who have
289 not used Catalyst before (it's sometimes written as C<$context>). The
290 Context object is automatically passed to all Catalyst components. It
291 is used to pass information between components and provide access to
292 Catalyst and plugin functionality.
294 Catalyst actions are regular Perl methods, but they make use of
295 attributes (the "C<: Local>" next to the "C<sub list>" in the code
296 above) to provide additional information to the Catalyst dispatcher
297 logic (note that the space between the colon and the attribute name is
298 optional... you will see attributes written both ways). Most Catalyst
299 Controllers use one of five action types:
305 B<:Private> -- Use C<:Private> for methods that you want to make into
306 an action, but you do not want Catalyst to directly expose the action
307 to your users. Catalyst will not map C<:Private> methods to a URI.
308 Use them for various sorts of "special" methods (the C<begin>,
309 C<auto>, etc. discussed below) or for methods you want to be able to
310 C<forward> or C<detach> to. (If the method is a plain old "helper
311 method" that you don't want to be an action at all, then just define
312 the method without any attribute -- you can call it in your code, but
313 the Catalyst dispatcher will ignore it.)
315 There are five types of "special" build-in C<:Private> actions:
316 C<begin>, C<end>, C<default>, C<index>, and C<auto>.
322 With C<begin>, C<end>, C<default>, C<index> private actions, only the
323 most specific action of each type will be called. For example, if you
324 define a C<begin> action in your controller it will I<override> a
325 C<begin> action in your application/root controller -- I<only> the
326 action in your controller will be called.
330 Unlike the other actions where only a single method is called for each
331 request, I<every> auto action along the chain of namespaces will be
332 called. Each C<auto> action will be called I<from the application/root
333 controller down through the most specific class>.
339 B<:Path> -- C<:Path> actions let you map a method to an explicit URI
340 path. For example, "C<:Path('list')>" in
341 C<lib/MyApp/Controller/Books.pm> would match on the URL
342 C<http://localhost:3000/books/list> but "C<:Path('/list')>" would match
343 on C<http://localhost:3000/list>. You can use C<:Args()> to specify
344 how many arguments an action should except. See
345 L<Catalyst::Manual::Intro/Action_types> for more information and a few
350 B<:Local> -- C<:Local> is merely a shorthand for
351 "C<:Path('_name_of_method_')>". For example, these are equivalent:
352 "C<sub create_book :Local {...}>" and
353 "C<sub create_book :Path('create_book') {...}>".
357 B<:Global> -- C<:Global> is merely a shorthand for
358 "C<:Path('/_name_of_method_')>". For example, these are equivalent:
359 "C<sub create_book :Global {...}>" and
360 "C<sub create_book :Path('/create_book') {...}>".
364 B<:Chained> -- Newer Catalyst applications tend to use the Chained
365 dispatch form of action types because of its power and flexibility.
366 It allows a series of controller methods to automatically be dispatched
367 to service a single user request. See
368 L<Catalyst::Manual::Tutorial::BasicCRUD|Catalyst::Manual::Tutorial::BasicCRUD>
369 and L<Catalyst::DispatchType::Chained|Catalyst::DispatchType::Chained>
370 for more information on chained actions.
374 You should refer to L<Catalyst::Manual::Intro/Action_types> for
375 additional information and for coverage of some lesser-used action
376 types not discussed here (C<Regex> and C<LocalRegex>).
379 =head1 CATALYST VIEWS
381 As mentioned in Part 2 of the tutorial, views are where you render
382 output, typically for display in the user's web browser (but also
383 possibly using other display output-generation systems). The code in
384 C<lib/MyApp/View> selects the I<type> of view to use, with the actual
385 rendering template found in the C<root> directory. As with virtually
386 every aspect of Catalyst, options abound when it comes to the specific
387 view technology you adopt inside your application. However, most
388 Catalyst applications use the Template Toolkit, known as TT (for more
389 information on TT, see L<http://www.template-toolkit.org>). Other
390 somewhat popular view technologies include Mason
391 (L<http://www.masonhq.com> and L<http://www.masonbook.com>) and
392 L<HTML::Template> (L<http://html-template.sourceforge.net>).
395 =head2 Create a Catalyst View
397 When using TT for the Catalyst view, there are two main helper scripts:
403 L<Catalyst::Helper::View::TT|Catalyst::Helper::View::TT>
407 L<Catalyst::Helper::View::TTSite|Catalyst::Helper::View::TTSite>
411 Both helpers are similar. C<TT> creates the C<lib/MyApp/View/TT.pm>
412 file and leaves the creation of any hierarchical template organization
413 entirely up to you. (It also creates a C<t/view_TT.t> file for testing;
414 test cases will be discussed in Part 8.) C<TTSite>, on the other hand,
415 creates a modular and hierarchical view layout with
416 separate Template Toolkit (TT) files for common header and footer
417 information, configuration values, a CSS stylesheet, and more.
419 While C<TTSite> was useful to bootstrap a project, its use is now
420 deprecated and to be considered historical. For most Catalyst
421 applications it adds redundant functionality and structure; many in the
422 Catalyst community recommend that it's easier to learn both Catalyst and
423 Template Toolkit if you use the more basic C<TT> approach.
424 Consequently, this tutorial will use "plain old TT."
426 Enter the following command to enable the C<TT> style of view
427 rendering for this tutorial:
429 $ script/myapp_create.pl view TT TT
430 exists "/home/me/MyApp/script/../lib/MyApp/View"
431 exists "/home/me/MyApp/script/../t"
432 created "/home/me/MyApp/script/../lib/MyApp/View/TT.pm"
433 created "/home/me/MyApp/script/../t/view_TT.t"
435 This simply creates a view called C<TT> (the second 'TT' argument) in
436 a file called C<TT.pm> (the first 'TT' argument). It is now up to you
437 to decide how you want to structure your view layout. For the
438 tutorial, we will start with a very simple TT template to initially
439 demonstrate the concepts, but quickly migrate to a more typical
440 "wrapper page" type of configuration (where the "wrapper" controls the
441 overall "look and feel" of your site from a single file or set of
444 Edit C<lib/MyApp/View/TT.pm> and you should see that the default
445 contents contains something similar to the following:
447 __PACKAGE__->config(TEMPLATE_EXTENSION => '.tt');
449 And update it to match:
452 # Change default TT extension
453 TEMPLATE_EXTENSION => '.tt2',
454 # Set the location for TT files
456 MyApp->path_to( 'root', 'src' ),
460 B<NOTE:> Make sure to add a comma after '.tt2' outside the single
463 This changes the default extension for Template Toolkit from '.tt' to
464 '.tt2' and changes the base directory for your template files from
465 C<root> to C<root/src>. These changes from the default are done mostly
466 to facilitate the application we're developing in this tutorial; as with
467 most things Perl, there's more than one way to do it...
470 =head2 Create a TT Template Page
472 First create a directory for book-related TT templates:
474 $ mkdir -p root/src/books
476 Then create C<root/src/books/list.tt2> in your editor and enter:
478 [% # This is a TT comment. The '-' at the end "chomps" the newline. You won't -%]
479 [% # see this "chomping" in your browser because HTML ignores blank lines, but -%]
480 [% # it WILL eliminate a blank line if you view the HTML source. It's purely -%]
481 [%- # optional, but both the beginning and the ending TT tags support chomping. -%]
483 [% # Provide a title -%]
484 [% META title = 'Book List' -%]
487 <tr><th>Title</th><th>Rating</th><th>Author(s)</th></tr>
488 [% # Display each book in a table row %]
489 [% FOREACH book IN books -%]
491 <td>[% book.title %]</td>
492 <td>[% book.rating %]</td>
497 As indicated by the inline comments above, the C<META title> line uses
498 TT's META feature to provide a title to the "wrapper" that we will
499 create later. Meanwhile, the C<FOREACH> loop iterates through each
500 C<book> model object and prints the C<title> and C<rating> fields.
502 If you are new to TT, the C<[%> and C<%]> tags are used to delimit TT
503 code. TT supports a wide variety of directives for "calling" other
504 files, looping, conditional logic, etc. In general, TT simplifies the
505 usual range of Perl operators down to the single dot (C<.>) operator.
506 This applies to operations as diverse as method calls, hash lookups, and
507 list index values (see
508 L<http://search.cpan.org/perldoc?Template::Manual::Variables>
509 for details and examples). In addition to the usual C<Template> module
510 Pod documentation, you can access the TT manual at
511 L<http://search.cpan.org/perldoc?Template::Manual>.
513 B<TIP:> While you can build all sorts of complex logic into your TT
514 templates, you should in general keep the "code" part of your templates
515 as simple as possible. If you need more complex logic, create helper
516 methods in your model that abstract out a set of code into a single call
517 from your TT template. (Note that the same is true of your controller
518 logic as well -- complex sections of code in your controllers should
519 often be pulled out and placed into your model objects.)
522 =head2 Test Run The Application
524 To test your work so far, first start the development server:
526 $ script/myapp_server.pl
528 Then point your browser to L<http://localhost:3000> and you should
529 still get the Catalyst welcome page. Next, change the URL in your
530 browser to L<http://localhost:3000/books/list>. If you have
531 everything working so far, you should see a web page that displays
532 nothing other than our column headers for "Title", "Rating", and
533 "Author(s)" -- we will not see any books until we get the database and
536 If you run into problems getting your application to run correctly, it
537 might be helpful to refer to some of the debugging techniques covered in
538 the L<Debugging|Catalyst::Manual::Tutorial::Debugging> part of the
542 =head1 CREATE A SQLITE DATABASE
544 In this step, we make a text file with the required SQL commands to
545 create a database table and load some sample data. We will use SQLite,
546 a popular database that is lightweight and easy to use. Open
547 C<myapp01.sql> in your editor and enter:
550 -- Create a very simple database to hold book and author information
553 id INTEGER PRIMARY KEY,
557 -- 'book_authors' is a many-to-many join table between books & authors
558 CREATE TABLE book_authors (
561 PRIMARY KEY (book_id, author_id)
563 CREATE TABLE authors (
564 id INTEGER PRIMARY KEY,
569 --- Load some sample data
571 INSERT INTO books VALUES (1, 'CCSP SNRS Exam Certification Guide', 5);
572 INSERT INTO books VALUES (2, 'TCP/IP Illustrated, Volume 1', 5);
573 INSERT INTO books VALUES (3, 'Internetworking with TCP/IP Vol.1', 4);
574 INSERT INTO books VALUES (4, 'Perl Cookbook', 5);
575 INSERT INTO books VALUES (5, 'Designing with Web Standards', 5);
576 INSERT INTO authors VALUES (1, 'Greg', 'Bastien');
577 INSERT INTO authors VALUES (2, 'Sara', 'Nasseh');
578 INSERT INTO authors VALUES (3, 'Christian', 'Degu');
579 INSERT INTO authors VALUES (4, 'Richard', 'Stevens');
580 INSERT INTO authors VALUES (5, 'Douglas', 'Comer');
581 INSERT INTO authors VALUES (6, 'Tom', 'Christiansen');
582 INSERT INTO authors VALUES (7, 'Nathan', 'Torkington');
583 INSERT INTO authors VALUES (8, 'Jeffrey', 'Zeldman');
584 INSERT INTO book_authors VALUES (1, 1);
585 INSERT INTO book_authors VALUES (1, 2);
586 INSERT INTO book_authors VALUES (1, 3);
587 INSERT INTO book_authors VALUES (2, 4);
588 INSERT INTO book_authors VALUES (3, 5);
589 INSERT INTO book_authors VALUES (4, 6);
590 INSERT INTO book_authors VALUES (4, 7);
591 INSERT INTO book_authors VALUES (5, 8);
593 Then use the following command to build a C<myapp.db> SQLite database:
595 $ sqlite3 myapp.db < myapp01.sql
597 If you need to create the database more than once, you probably want to
598 issue the C<rm myapp.db> command to delete the database before you use
599 the C<sqlite3 myapp.db E<lt> myapp01.sql> command.
601 Once the C<myapp.db> database file has been created and initialized, you
602 can use the SQLite command line environment to do a quick dump of the
607 Enter ".help" for instructions
608 sqlite> select * from books;
609 1|CCSP SNRS Exam Certification Guide|5
610 2|TCP/IP Illustrated, Volume 1|5
611 3|Internetworking with TCP/IP Vol.1|4
613 5|Designing with Web Standards|5
619 $ sqlite3 myapp.db "select * from books"
620 1|CCSP SNRS Exam Certification Guide|5
621 2|TCP/IP Illustrated, Volume 1|5
622 3|Internetworking with TCP/IP Vol.1|4
624 5|Designing with Web Standards|5
626 As with most other SQL tools, if you are using the full "interactive"
627 environment you need to terminate your SQL commands with a ";" (it's not
628 required if you do a single SQL statement on the command line). Use
629 ".q" to exit from SQLite from the SQLite interactive mode and return to
630 your OS command prompt.
632 For using other databases, such as PostgreSQL or MySQL, see
633 L<Appendix 2|Catalyst::Manual::Tutorial::Appendices>.
635 =head1 DATABASE ACCESS WITH C<DBIx::Class>
637 Catalyst can be used with virtually any form of persistent datastore
638 available via Perl. For example,
639 L<Catalyst::Model::DBI|Catalyst::Model::DBI> can be used to easily
640 access databases through the traditional Perl C<DBI> interface. However,
641 most Catalyst applications use some form of ORM technology to
642 automatically create and save model objects as they are used. Although
643 L<Class::DBI|Class::DBI> has been a popular choice in the past, Matt
644 Trout's L<DBIx::Class|DBIx::Class> (abbreviated as "DBIC") has rapidly
645 emerged as the Perl-based ORM technology of choice. Most new Catalyst
646 applications rely on DBIC, as will this tutorial.
649 =head2 Create a Dynamic DBIC Model
651 Use the C<create=dynamic> model helper option to build a model that
652 dynamically reads your database structure every time the application
655 $ script/myapp_create.pl model DB DBIC::Schema MyApp::Schema create=dynamic dbi:SQLite:myapp.db
656 exists "/home/me/MyApp/script/../lib/MyApp/Model"
657 exists "/home/me/MyApp/script/../t"
658 exists "/home/me/MyApp/script/../lib/MyApp"
659 created "/home/me/MyApp/script/../lib/MyApp/Schema.pm"
660 created "/home/me/MyApp/script/../lib/MyApp/Model/DB.pm"
661 created "/home/me/MyApp/script/../t/model_DB.t"
664 The C<script/myapp_create.pl> command breaks down like this:
670 C<DB> is the name of the model class to be created by the helper in
675 C<DBIC::Schema> is the type of the model to create.
679 C<MyApp::Schema> is the name of the DBIC schema file written to
680 C<lib/MyApp/Schema.pm>.
684 Because we specified C<create=dynamic> to the helper, it use
685 L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> to
686 dynamically load the schema information from the database every time
687 the application starts.
691 And finally, C<dbi:SQLite:myapp.db> is the standard DBI connect string
696 B<NOTE:> Although the C<create=dynamic> option to the DBIC helper
697 makes for a nifty demonstration, is only really suitable for very
698 small applications. After this demonstration, you should almost always
699 use the C<create=static> option that we switch to below.
702 =head1 ENABLE THE MODEL IN THE CONTROLLER
704 Open C<lib/MyApp/Controller/Books.pm> and un-comment the model code we
705 left disabled earlier (un-comment the line containing
706 C<[$c-E<gt>model('DB::Books')-E<gt>all]> and delete the next 2 lines):
710 Fetch all book objects and pass to books/list.tt2 in stash to be displayed
715 # Retrieve the usual Perl OO '$self' for this object. $c is the Catalyst
716 # 'Context' that's used to 'glue together' the various components
717 # that make up the application
720 # Retrieve all of the book records as book model objects and store in the
721 # stash where they can be accessed by the TT template
722 $c->stash->{books} = [$c->model('DB::Books')->all];
724 # Set the TT template to use. You will almost always want to do this
725 # in your action methods (action methods respond to user input in
727 $c->stash->{template} = 'books/list.tt2';
730 B<TIP>: You may see the C<$c-E<gt>model('DB::Books')> un-commented
731 above written as C<$c-E<gt>model('DB')-E<gt>resultset('Books')>. The
732 two are equivalent. Either way, C<$c-E<gt>model> returns a
733 L<DBIx::Class::ResultSet|DBIx::Class::ResultSet> which handles queries
734 against the database and iterating over the set of results that are
737 We are using the C<-E<gt>all> to fetch all of the books. DBIC
738 supports a wide variety of more advanced operations to easily do
739 things like filtering and sorting the results. For example, the
740 following could be used to sort the results by descending title:
742 $c->model('DB::Books')->search({}, {order_by => 'title DESC'});
744 Some other examples are provided in
745 L<DBIx::Class::Manual::Cookbook/Complex WHERE clauses>, with
746 additional information found at L<DBIx::Class::ResultSet/search>,
747 L<DBIx::Class::Manual::FAQ/Searching>,
748 L<DBIx::Class::Manual::Intro|DBIx::Class::Manual::Intro>
749 and L<Catalyst::Model::DBIC::Schema|Catalyst::Model::DBIC::Schema>.
752 =head2 Test Run The Application
754 First, let's enable an environment variable that causes DBIx::Class to
755 dump the SQL statements usedß to access the database. This is a
756 helpful trick when you are trying to debug your database-oriented
759 $ export DBIC_TRACE=1
761 This assumes you are using BASH as your shell -- adjust accordingly if
762 you are using a different shell (for example, under tcsh, use
763 C<setenv DBIC_TRACE 1>).
765 B<NOTE:> You can also set this in your code using
766 C<$class-E<gt>storage-E<gt>debug(1);>. See
767 L<DBIx::Class::Manual::Troubleshooting> for details (including options
768 to log to file instead of displaying to the Catalyst development server
771 Then launch the Catalyst development server. The log output should
772 display something like:
774 $script/myapp_server.pl
775 [debug] Debug messages enabled
776 [debug] Statistics enabled
777 [debug] Loaded plugins:
778 .----------------------------------------------------------------------------.
779 | Catalyst::Plugin::ConfigLoader 0.20 |
780 | Catalyst::Plugin::StackTrace 0.08 |
781 | Catalyst::Plugin::Static::Simple 0.20 |
782 '----------------------------------------------------------------------------'
784 [debug] Loaded dispatcher "Catalyst::Dispatcher"
785 [debug] Loaded engine "Catalyst::Engine::HTTP"
786 [debug] Found home "/home/me/MyApp"
787 [debug] Loaded Config "/home/me/MyApp/myapp.conf"
788 [debug] Loaded components:
789 .-----------------------------------------------------------------+----------.
791 +-----------------------------------------------------------------+----------+
792 | MyApp::Controller::Books | instance |
793 | MyApp::Controller::Root | instance |
794 | MyApp::Model::DB | instance |
795 | MyApp::Model::DB::Authors | class |
796 | MyApp::Model::DB::BookAuthors | class |
797 | MyApp::Model::DB::Books | class |
798 | MyApp::View::TT | instance |
799 '-----------------------------------------------------------------+----------'
801 [debug] Loaded Private actions:
802 .----------------------+--------------------------------------+--------------.
803 | Private | Class | Method |
804 +----------------------+--------------------------------------+--------------+
805 | /default | MyApp::Controller::Root | default |
806 | /end | MyApp::Controller::Root | end |
807 | /index | MyApp::Controller::Root | index |
808 | /books/index | MyApp::Controller::Books | index |
809 | /books/list | MyApp::Controller::Books | list |
810 '----------------------+--------------------------------------+--------------'
812 [debug] Loaded Path actions:
813 .-------------------------------------+--------------------------------------.
815 +-------------------------------------+--------------------------------------+
818 | /books | /books/index |
819 | /books/list | /books/list |
820 '-------------------------------------+--------------------------------------'
822 [info] MyApp powered by Catalyst 5.7014
823 You can connect to your server at http://localhost:3000
825 B<NOTE:> Be sure you run the C<script/myapp_server.pl> command from
826 the 'base' directory of your application, not inside the C<script>
827 directory itself or it will not be able to locate the C<myapp.db>
828 database file. You can use a fully qualified or a relative path to
829 locate the database file, but we did not specify that when we ran the
830 model helper earlier.
832 Some things you should note in the output above:
838 Catalyst::Model::DBIC::Schema dynamically created three model classes,
839 one to represent each of the three tables in our database
840 (C<MyApp::Model::DB::Authors>, C<MyApp::Model::DB::BookAuthors>,
841 and C<MyApp::Model::DB::Books>).
845 The "list" action in our Books controller showed up with a path of
850 Point your browser to L<http://localhost:3000> and you should still get
851 the Catalyst welcome page.
853 Next, to view the book list, change the URL in your browser to
854 L<http://localhost:3000/books/list>. You should get a list of the five
855 books loaded by the C<myapp01.sql> script above without any formatting.
856 The rating for each book should appear on each row, but the "Author(s)"
857 column will still be blank (we will fill that in later).
859 Also notice in the output of the C<script/myapp_server.pl> that DBIC
860 used the following SQL to retrieve the data:
862 SELECT me.id, me.title, me.rating FROM books me
864 because we enabled DBIC_TRACE.
866 You now have the beginnings of a simple but workable web application.
867 Continue on to future sections and we will develop the application
871 =head1 CREATE A WRAPPER FOR THE VIEW
873 When using TT, you can (and should!) create a wrapper that will
874 literally wrap content around each of your templates. This is
875 certainly useful as you have one main source for changing things that
876 will appear across your entire site/application instead of having to
877 edit many individual files.
880 =head2 Configure TT.pm For The Wrapper
882 In order to create a wrapper, you must first edit your TT view and
883 tell it where to find your wrapper file. Your TT view is located in
884 C<lib/MyApp/View/TT.pm>.
886 Edit C<lib/MyApp/View/TT.pm> and change it to match the following:
889 # Change default TT extension
890 TEMPLATE_EXTENSION => '.tt2',
891 # Set the location for TT files
893 MyApp->path_to( 'root', 'src' ),
895 # Set to 1 for detailed timer stats in your HTML as comments
897 # This is your wrapper template located in the 'root/src'
898 WRAPPER => 'wrapper.tt2',
902 =head2 Create the Wrapper Template File and Stylesheet
904 Next you need to set up your wrapper template. Basically, you'll want
905 to take the overall layout of your site and put it into this file.
906 For the tutorial, open C<root/src/wrapper.tt2> and input the following:
908 <?xml version="1.0" encoding="UTF-8"?>
909 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
910 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
912 <title>[% template.title or "My Catalyst App!" %]</title>
913 <link rel="stylesheet" href="[% c.uri_for('/static/css/main.css') %]" />
919 [%# Your logo could go here -%]
920 <img src="[% c.uri_for('/static/images/btn_88x31_powered.png') %]" />
921 [%# Insert the page title -%]
922 <h1>[% template.title or site.title %]</h1>
929 <li><a href="[% c.uri_for('/books/list') %]">Home</a></li>
930 <li><a href="[% c.uri_for('/') %]" title="Catalyst Welcome Page">Welcome</a></li>
931 <li><a href="mailto:nobody@nowhere.com" title="Contact Us">Contact Us</a></li>
933 </div><!-- end menu -->
936 [%# Status and error messages %]
937 <span class="message">[% status_msg %]</span>
938 <span class="error">[% error_msg %]</span>
939 [%# This is where TT will stick all of your template's contents. -%]
941 </div><!-- end content -->
942 </div><!-- end bodyblock -->
944 <div id="footer">Copyright (c) your name goes here</div>
945 </div><!-- end outer -->
950 Notice the status and error message sections in the code above:
952 <span class="status">[% status_msg %]</span>
953 <span class="error">[% error_msg %]</span>
955 If we set either message in the Catalyst stash (e.g.,
956 C<$c-E<gt>stash-E<gt>{status_msg} = 'Request was successful!'>) it
957 will be displayed whenever any view used by that request is rendered.
958 The C<message> and C<error> CSS styles can be customized to suit your
959 needs in the C<root/static/css/main.css> file we create below.
967 The Catalyst stash only lasts for a single HTTP request. If
968 you need to retain information across requests you can use
969 L<Catalyst::Plugin::Session|Catalyst::Plugin::Session> (we will use
970 Catalyst sessions in the Authentication part of the tutorial).
974 Although it is beyond the scope of this tutorial, you may wish to use
975 a JavaScript or AJAX tool such as jQuery (L<http://www.jquery.com>) or
976 Dojo (L<http://www.dojotoolkit.org>).
981 =head3 Create A Basic Stylesheet
983 First create a central location for stylesheets under the static
986 $ mkdir root/static/css
988 Then open the file C<root/static/css/main.css> (the file referenced in
989 the stylesheet href link of our wrapper above) and add the following
1008 background-color: #ddd;
1014 padding: 0 0 50% 5px;
1015 font-weight: normal;
1016 background-color: #ddd;
1029 You may wish to check out a "CSS Framework" like Emastic
1030 (L<http://code.google.com/p/emastic/>) as a way to quickly
1031 provide lots of high-quality CSS functionality.
1034 =head2 Test Run The Application
1036 Restart the development server and hit "Reload" in your web browser
1037 and you should now see a formatted version of our basic book list.
1038 Although our wrapper and stylesheet are obviously very simple, you
1039 should see how it allows us to control the overall look of an entire
1040 website from two central files. To add new pages to the site, just
1041 provide a template that fills in the C<content> section of our wrapper
1042 template -- the wrapper will provide the overall feel of the page.
1045 =head1 A STATIC DATABASE MODEL WITH C<DBIx::Class>
1047 =head2 Create Static DBIC Schema Files
1049 Unlike the previous DBIC section where we had C<create=dynamic>
1050 automatically discover the structure of the database every time the
1051 application started, here we will use static schema files for more
1052 control. This is typical of most "real world" applications.
1054 One option would be to manually create a separate schema file for each
1055 table in the database, however, lets use the same
1056 L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> used
1057 earlier with C<create=dynamic> to build the static files for us.
1058 First, lets remove the schema file created earlier:
1060 $ rm lib/MyApp/Schema.pm
1062 Now regenerate the schema using the C<create=static> option:
1064 $ script/myapp_create.pl model DB DBIC::Schema MyApp::Schema create=static dbi:SQLite:myapp.db
1065 exists "/home/kclark/dev/MyApp/script/../lib/MyApp/Model"
1066 exists "/home/kclark/dev/MyApp/script/../t"
1067 Dumping manual schema for MyApp::Schema to directory /home/kclark/dev/MyApp/script/../lib ...
1068 Schema dump completed.
1069 exists "/home/kclark/dev/MyApp/script/../lib/MyApp/Model/DB.pm"
1071 We could have also deleted C<lib/MyApp/Model/DB.pm>, but it would
1072 have regenerated the same file (note the C<exists> in the output above).
1073 If you take a look at C<lib/MyApp/Model/DB.pm>, it simply contains
1074 a reference to the actual schema file in C<lib/MyApp/Schema.pm>
1075 along with the database connect string.
1077 If you look in the C<lib/MyApp/Schema.pm> file, you will find that it
1079 L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> as its base
1080 class (L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> is
1081 only being used by the helper to load the schema once and then create
1082 the static files for us) and C<Schema.pm> only contains a call to the
1083 C<load_classes> method. You will also find that C<lib/MyApp>
1084 contains a C<Schema> subdirectory, with one file inside this directory
1085 for each of the tables in our simple database (C<Authors.pm>,
1086 C<BookAuthors.pm>, and C<Books.pm>). These three files were created
1087 based on the information found by
1088 L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> as the
1091 The idea with all of the files created under C<lib/MyApp/Schema> by
1092 the C<create=static> option is to only edit the files below the C<# DO
1093 NOT MODIFY THIS OR ANYTHING ABOVE!> warning. If you place all of your
1094 changes below that point in the file, you can regenerate the
1095 automatically created information at the top of each file should your
1096 database structure get updated.
1098 Also note the "flow" of the model information across the various files
1099 and directories. Catalyst will initially load the model from
1100 C<lib/MyApp/Model/DB.pm>. This file contains a reference to
1101 C<lib/MyApp/Schema.pm>, so that file is loaded next. Finally,
1102 the call to C<load_classes> in C<Schema.pm> will load each of the
1103 table-specific "results source" files from the C<lib/MyApp/Schema>
1104 subdirectory. These three table-specific DBIC schema files will then be
1105 used to create three table-specific Catalyst models every time the
1106 application starts (you can see these three model files listed in
1107 the debug output generated when you launch the application).
1110 =head2 Updating the Generated DBIC Schema Files
1112 Let's manually add some relationship information to the auto-generated
1113 schema files. First edit C<lib/MyApp/Schema/Books.pm> and
1114 add the following text below the C<# You can replace this text...>
1118 # Set relationships:
1123 # 1) Name of relationship, DBIC will create accessor with this name
1124 # 2) Name of the model class referenced by this relationship
1125 # 3) Column name in *foreign* table (aka, foreign key in peer table)
1126 __PACKAGE__->has_many(book_authors => 'MyApp::Schema::BookAuthors', 'book_id');
1130 # 1) Name of relationship, DBIC will create accessor with this name
1131 # 2) Name of has_many() relationship this many_to_many() is shortcut for
1132 # 3) Name of belongs_to() relationship in model class of has_many() above
1133 # You must already have the has_many() defined to use a many_to_many().
1134 __PACKAGE__->many_to_many(authors => 'book_authors', 'author');
1137 B<Note:> Be careful to put this code I<above> the C<1;> at the end of the
1138 file. As with any Perl package, we need to end the last line with
1139 a statement that evaluates to C<true>. This is customarily done with
1140 C<1;> on a line by itself.
1142 This code defines both a C<has_many> and a C<many_to_many> relationship.
1143 The C<many_to_many> relationship is optional, but it makes it easier to
1144 map a book to its collection of authors. Without it, we would have to
1145 "walk" though the C<book_authors> table as in
1146 C<$book-E<gt>book_authors-E<gt>first-E<gt>author-E<gt>last_name>
1147 (we will see examples on how to use DBIC objects in your code soon,
1148 but note that because C<$book-E<gt>book_authors> can return multiple
1149 authors, we have to use C<first> to display a single author).
1150 C<many_to_many> allows us to use the shorter
1151 C<$book-E<gt>authors-E<gt>first-E<gt>last_name>.
1152 Note that you cannot define a C<many_to_many> relationship without
1153 also having the C<has_many> relationship in place.
1155 Then edit C<lib/MyApp/Schema/Authors.pm> and add relationship
1156 information as follows (again, be careful to put in above the C<1;> but
1157 below the C<# DO NOT MODIFY THIS OR ANYTHING ABOVE!> comment):
1160 # Set relationships:
1165 # 1) Name of relationship, DBIC will create accessor with this name
1166 # 2) Name of the model class referenced by this relationship
1167 # 3) Column name in *foreign* table (aka, foreign key in peer table)
1168 __PACKAGE__->has_many(book_author => 'MyApp::Schema::BookAuthors', 'author_id');
1172 # 1) Name of relationship, DBIC will create accessor with this name
1173 # 2) Name of has_many() relationship this many_to_many() is shortcut for
1174 # 3) Name of belongs_to() relationship in model class of has_many() above
1175 # You must already have the has_many() defined to use a many_to_many().
1176 __PACKAGE__->many_to_many(books => 'book_author', 'book');
1178 Finally, do the same for the "join table,"
1179 C<lib/MyApp/Schema/BookAuthors.pm>:
1182 # Set relationships:
1187 # 1) Name of relationship, DBIC will create accessor with this name
1188 # 2) Name of the model class referenced by this relationship
1189 # 3) Column name in *this* table
1190 __PACKAGE__->belongs_to(book => 'MyApp::Schema::Books', 'book_id');
1194 # 1) Name of relationship, DBIC will create accessor with this name
1195 # 2) Name of the model class referenced by this relationship
1196 # 3) Column name in *this* table
1197 __PACKAGE__->belongs_to(author => 'MyApp::Schema::Authors', 'author_id');
1200 =head2 Run The Application
1202 Run the Catalyst "demo server" script with the C<DBIC_TRACE> option
1203 (it might still be enabled from earlier in the tutorial, but here
1204 is an alternate way to specify the option just in case):
1206 $ DBIC_TRACE=1 script/myapp_server.pl
1208 Make sure that the application loads correctly and that you see the
1209 three dynamically created model class (one for each of the
1210 table-specific schema classes we created).
1212 Then hit the URL L<http://localhost:3000/books/list> and be sure that
1213 the book list is displayed via the relationships established above. You
1214 can leave the development server running for the next step if you wish.
1216 B<Note:> You will not see the authors yet because the view does not yet
1217 use the new relations. Read on to the next section where we update the
1218 template to do that.
1221 =head1 UPDATING THE VIEW
1223 Let's add a new column to our book list page that takes advantage of
1224 the relationship information we manually added to our schema files
1225 in the previous section. Edit C<root/src/books/list.tt2> add add the
1226 following code below the existing table cell that contains
1227 C<book.rating> (IOW, add a new table cell below the existing two
1231 [% # First initialize a TT variable to hold a list. Then use a TT FOREACH -%]
1232 [% # loop in 'side effect notation' to load just the last names of the -%]
1233 [% # authors into the list. Note that the 'push' TT vmethod does not print -%]
1234 [% # a value, so nothing will be printed here. But, if you have something -%]
1235 [% # in TT that does return a method and you don't want it printed, you -%]
1236 [% # can: 1) assign it to a bogus value, or 2) use the CALL keyword to -%]
1237 [% # call it and discard the return value. -%]
1238 [% tt_authors = [ ];
1239 tt_authors.push(author.last_name) FOREACH author = book.authors %]
1240 [% # Now use a TT 'virtual method' to display the author count in parens -%]
1241 [% # Note the use of the TT filter "| html" to escape dangerous characters -%]
1242 ([% tt_authors.size | html %])
1243 [% # Use another TT vmethod to join & print the names & comma separators -%]
1244 [% tt_authors.join(', ') | html %]
1247 Then hit "Reload" in your browser (note that you don't need to reload
1248 the development server or use the C<-r> option when updating TT
1249 templates) and you should now see the number of authors each book has
1250 along with a comma-separated list of the authors' last names. (If you
1251 didn't leave the development server running from the previous step,
1252 you will obviously need to start it before you can refresh your
1255 If you are still running the development server with C<DBIC_TRACE>
1256 enabled, you should also now see five more C<SELECT> statements in the
1257 debug output (one for each book as the authors are being retrieved by
1260 SELECT me.id, me.title, me.rating FROM books me:
1261 SELECT me.book_id, me.author_id FROM book_authors me WHERE ( me.book_id = ? ): '1'
1262 SELECT me.book_id, me.author_id FROM book_authors me WHERE ( me.book_id = ? ): '2'
1263 SELECT me.book_id, me.author_id FROM book_authors me WHERE ( me.book_id = ? ): '3'
1264 SELECT me.book_id, me.author_id FROM book_authors me WHERE ( me.book_id = ? ): '4'
1265 SELECT me.book_id, me.author_id FROM book_authors me WHERE ( me.book_id = ? ): '5'
1267 Also note in C<root/src/books/list.tt2> that we are using "| html", a
1268 type of TT filter, to escape characters such as E<lt> and E<gt> to <
1269 and > and avoid various types of dangerous hacks against your
1270 application. In a real application, you would probably want to put
1271 "| html" at the end of every field where a user has control over the
1272 information that can appear in that field (and can therefore inject
1273 markup or code if you don't "neutralize" those fields). In addition to
1274 "| html", Template Toolkit has a variety of other useful filters that
1275 can found in the documentation for
1276 L<Template::Filters|Template::Filters>.
1279 =head1 RUNNING THE APPLICATION FROM THE COMMAND LINE
1281 In some situations, it can be useful to run your application and
1282 display a page without using a browser. Catalyst lets you do this
1283 using the C<scripts/myapp_test.pl> script. Just supply the URL you
1284 wish to display and it will run that request through the normal
1285 controller dispatch logic and use the appropriate view to render the
1286 output (obviously, complex pages may dump a lot of text to your
1287 terminal window). For example, if you type:
1289 $ script/myapp_test.pl "/books/list"
1291 You should get the same text as if you visited
1292 L<http://localhost:3000/books/list> with the normal development server
1293 and asked your browser to view the page source.
1296 =head1 OPTIONAL INFORMATION
1298 B<NOTE: The rest of this part of the tutorial is optional. You can
1299 skip to Part 4, L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD>,
1302 =head2 Using C<RenderView> for the Default View
1304 Once your controller logic has processed the request from a user, it
1305 forwards processing to your view in order to generate the appropriate
1306 response output. Catalyst uses
1307 L<Catalyst::Action::RenderView|Catalyst::Action::RenderView> by
1308 default to automatically performs this operation. If you look in
1309 C<lib/MyApp/Controller/Root.pm>, you should see the empty
1310 definition for the C<sub end> method:
1312 sub end : ActionClass('RenderView') {}
1314 The following bullet points provide a quick overview of the
1315 C<RenderView> process:
1321 C<Root.pm> is designed to hold application-wide logic.
1325 At the end of a given user request, Catalyst will call the most specific
1326 C<end> method that's appropriate. For example, if the controller for a
1327 request has an C<end> method defined, it will be called. However, if
1328 the controller does not define a controller-specific C<end> method, the
1329 "global" C<end> method in C<Root.pm> will be called.
1333 Because the definition includes an C<ActionClass> attribute, the
1334 L<Catalyst::Action::RenderView|Catalyst::Action::RenderView> logic
1335 will be executed B<after> any code inside the definition of C<sub end>
1336 is run. See L<Catalyst::Manual::Actions|Catalyst::Manual::Actions>
1337 for more information on C<ActionClass>.
1341 Because C<sub end> is empty, this effectively just runs the default
1342 logic in C<RenderView>. However, you can easily extend the
1343 C<RenderView> logic by adding your own code inside the empty method body
1344 (C<{}>) created by the Catalyst Helpers when we first ran the
1345 C<catalyst.pl> to initialize our application. See
1346 L<Catalyst::Action::RenderView|Catalyst::Action::RenderView> for more
1347 detailed information on how to extended C<RenderView> in C<sub end>.
1352 =head2 Using The Default Template Name
1354 By default, C<Catalyst::View::TT> will look for a template that uses the
1355 same name as your controller action, allowing you to save the step of
1356 manually specifying the template name in each action. For example, this
1357 would allow us to remove the
1358 C<$c-E<gt>stash-E<gt>{template} = 'books/list.tt2';> line of our
1359 C<list> action in the Books controller. Open
1360 C<lib/MyApp/Controller/Books.pm> in your editor and comment out this line
1361 to match the following (only the C<$c-E<gt>stash-E<gt>{template}> line
1366 Fetch all book objects and pass to books/list.tt2 in stash to be displayed
1371 # Retrieve the usual Perl OO '$self' for this object. $c is the Catalyst
1372 # 'Context' that's used to 'glue together' the various components
1373 # that make up the application
1374 my ($self, $c) = @_;
1376 # Retrieve all of the book records as book model objects and store in the
1377 # stash where they can be accessed by the TT template
1378 $c->stash->{books} = [$c->model('DB::Books')->all];
1380 # Set the TT template to use. You will almost always want to do this
1381 # in your action methods (actions methods respond to user input in
1382 # your controllers).
1383 #$c->stash->{template} = 'books/list.tt2';
1387 You should now be able to restart the development server as per the
1388 previous section and access the L<http://localhost:3000/books/list>
1391 B<NOTE:> Please note that if you use the default template technique,
1392 you will B<not> be able to use either the C<$c-E<gt>forward> or
1393 the C<$c-E<gt>detach> mechanisms (these are discussed in Part 2 and
1394 Part 9 of the Tutorial).
1397 =head2 Return To A Manually-Specified Template
1399 In order to be able to use C<$c-E<gt>forward> and C<$c-E<gt>detach>
1400 later in the tutorial, you should remove the comment from the
1401 statement in C<sub list> in C<lib/MyApp/Controller/Books.pm>:
1403 $c->stash->{template} = 'books/list.tt2';
1405 Then delete the C<TEMPLATE_EXTENSION> line in
1406 C<lib/MyApp/View/TT.pm>.
1408 You should then be able to restart the development server and
1409 access L<http://localhost:3000/books/list> in the same manner as
1410 with earlier sections.
1415 Kennedy Clark, C<hkclark@gmail.com>
1417 Please report any errors, issues or suggestions to the author. The
1418 most recent version of the Catalyst Tutorial can be found at
1419 L<http://dev.catalyst.perl.org/repos/Catalyst/Catalyst-Manual/5.70/trunk/lib/Catalyst/Manual/Tutorial/>.
1421 Copyright 2006-2008, Kennedy Clark, under Creative Commons License
1422 (L<http://creativecommons.org/licenses/by-sa/3.0/us/>).