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, you need to
145 be aware that Catalyst changed from a default format of YAML to the
146 more straightforward C<Config::General> format. This tutorial use the
147 newer C<myapp.conf> configuration file for C<Config::General> instead
148 of C<myapp.yml> for YAML. However, Catalyst has long supported both
149 formats and Catalyst will automatically use either C<myapp.conf> or
150 C<myapp.yml> (or any other format supported by
151 L<Catalyst::Plugin::ConfigLoader|Catalyst::Plugin::ConfigLoader> and
152 L<Config::Any|Config::Any>). If you are using a versions of
153 Catalyst::Devel prior to 1.06, you can convert to the newer format by
154 simply creating the C<myapp.conf> file manually and deleting
155 C<myapp.yml>. The default contents of C<myapp.conf> should only
156 consist of one line: C<name MyApp>.
158 B<TIP>: This script can be useful for converting between configuration
161 perl -Ilib -e 'use MyApp; use Config::General;
162 Config::General->new->save_file("myapp.conf", MyApp->config);'
164 B<NOTE:> The default C<myapp.conf> should look like:
170 L<Catalyst::Plugin::Static::Simple|Catalyst::Plugin::Static::Simple>
172 C<Static::Simple> provides an easy method of serving static content such
173 as images and CSS files under the development server.
177 For our application, we want to add one new plugin into the mix. To
178 do this, edit C<lib/MyApp.pm> (this file is generally referred to as
179 your I<application class>) and delete the line with:
181 __PACKAGE__->setup(qw/-Debug ConfigLoader Static::Simple/);
183 Then replace it with:
185 __PACKAGE__->setup(qw/
193 B<Note:> Recent versions of C<Catalyst::Devel> have used a variety of
194 techniques to load these plugins/flags. If you are following along in
195 Ubuntu 8.10, you should have C<Catalyst::Devel> v1.07 and see the
196 default code shown above. If you are using v1.08, you should see the
197 following by default:
199 use Catalyst qw/-Debug
203 __PACKAGE__->setup();
205 Don't let these variations confuse you -- they all accomplish the same
208 This tells Catalyst to start using one new plugin,
209 L<Catalyst::Plugin::StackTrace|Catalyst::Plugin::StackTrace>, to add a
210 stack trace to the standard Catalyst "debug screen" (the screen
211 Catalyst sends to your browser when an error occurs). Be aware that
212 L<StackTrace|Catalyst::Plugin::StackTrace> output appears in your
213 browser, not in the console window from which you're running your
214 application, which is where logging output usually goes.
222 C<__PACKAGE__> is just a shorthand way of referencing the name of the
223 package where it is used. Therefore, in C<MyApp.pm>, C<__PACKAGE__>
224 is equivalent to C<MyApp>.
228 You will want to disable L<StackTrace|Catalyst::Plugin::StackTrace>
229 before you put your application into production, but it can be helpful
234 When specifying plugins on the C<__PACKAGE__-E<gt>setup> line, you can
235 omit C<Catalyst::Plugin::> from the name. Additionally, you can
236 spread the plugin names across multiple lines as shown here, or place
237 them all on one (or more) lines as with the default configuration.
242 =head1 CREATE A CATALYST CONTROLLER
244 As discussed earlier, controllers are where you write methods that
245 interact with user input. Typically, controller methods respond to
246 C<GET> and C<POST> messages from the user's web browser.
248 Use the Catalyst C<create> script to add a controller for book-related
251 $ script/myapp_create.pl controller Books
252 exists "/home/me/MyApp/script/../lib/MyApp/Controller"
253 exists "/home/me/MyApp/script/../t"
254 created "/home/me/MyApp/script/../lib/MyApp/Controller/Books.pm"
255 created "/home/me/MyApp/script/../t/controller_Books.t"
257 Then edit C<lib/MyApp/Controller/Books.pm> (as discussed in Part 2 of
258 the Tutorial, Catalyst has a separate directory under C<lib/MyApp> for
259 each of the three parts of MVC: C<Model>, C<View>, and C<Controller>)
260 and add the following method to the controller:
264 Fetch all book objects and pass to books/list.tt2 in stash to be displayed
269 # Retrieve the usual Perl OO '$self' for this object. $c is the Catalyst
270 # 'Context' that's used to 'glue together' the various components
271 # that make up the application
274 # Retrieve all of the book records as book model objects and store in the
275 # stash where they can be accessed by the TT template
276 # $c->stash->{books} = [$c->model('DB::Books')->all];
277 # But, for now, use this code until we create the model later
278 $c->stash->{books} = '';
280 # Set the TT template to use. You will almost always want to do this
281 # in your action methods (action methods respond to user input in
283 $c->stash->{template} = 'books/list.tt2';
286 B<TIP>: See Appendix 1 for tips on removing the leading spaces when
287 cutting and pasting example code from POD-based documents.
289 Programmers experienced with object-oriented Perl should recognize
290 C<$self> as a reference to the object where this method was called.
291 On the other hand, C<$c> will be new to many Perl programmers who have
292 not used Catalyst before (it's sometimes written as C<$context>). The
293 Context object is automatically passed to all Catalyst components. It
294 is used to pass information between components and provide access to
295 Catalyst and plugin functionality.
297 Catalyst actions are regular Perl methods, but they make use of
298 attributes (the "C<: Local>" next to the "C<sub list>" in the code
299 above) to provide additional information to the Catalyst dispatcher
300 logic (note that the space between the colon and the attribute name is
301 optional... you will see attributes written both ways). Most Catalyst
302 Controllers use one of five action types:
308 B<:Private> -- Use C<:Private> for methods that you want to make into
309 an action, but you do not want Catalyst to directly expose the action
310 to your users. Catalyst will not map C<:Private> methods to a URI.
311 Use them for various sorts of "special" methods (the C<begin>,
312 C<auto>, etc. discussed below) or for methods you want to be able to
313 C<forward> or C<detach> to. (If the method is a plain old "helper
314 method" that you don't want to be an action at all, then just define
315 the method without any attribute -- you can call it in your code, but
316 the Catalyst dispatcher will ignore it.)
318 There are five types of "special" build-in C<:Private> actions:
319 C<begin>, C<end>, C<default>, C<index>, and C<auto>.
323 With C<begin>, C<end>, C<default>, C<index> private actions, only the
324 most specific action of each type will be called. For example, if you
325 define a C<begin> action in your controller it will I<override> a
326 C<begin> action in your application/root controller -- I<only> the
327 action in your controller will be called.
331 Unlike the other actions where only a single method is called for each
332 request, I<every> auto action along the chain of namespaces will be
333 called. Each C<auto> action will be called I<from the application/root
334 controller down through the most specific class>.
340 B<:Path> -- C<:Path> actions let you map a method to an explicit URI
341 path. For example, "C<:Path('list')>" in
342 C<lib/MyApp/Controller/Books.pm> would match on the URL
343 C<http://localhost:3000/books/list> but "C<:Path('/list')>" would match
344 on C<http://localhost:3000/list>. You can use C<:Args()> to specify
345 how many arguments an action should except. See
346 L<Catalyst::Manual::Intro/Action_types> for more information and a few
351 B<:Local> -- C<:Local> is merely a shorthand for
352 "C<:Path('_name_of_method_')>". For example, these are equivalent:
353 "C<sub create_book :Local {...}>" and
354 "C<sub create_book :Path('create_book') {...}>".
358 B<:Global> -- C<:Global> is merely a shorthand for
359 "C<:Path('/_name_of_method_')>". For example, these are equivalent:
360 "C<sub create_book :Global {...}>" and
361 "C<sub create_book :Path('/create_book') {...}>".
365 B<:Chained> -- Newer Catalyst applications tend to use the Chained
366 dispatch form of action types because of its power and flexibility.
367 It allows a series of controller methods to automatically be dispatched
368 to service a single user request. See
369 L<Catalyst::Manual::Tutorial::BasicCRUD|Catalyst::Manual::Tutorial::BasicCRUD>
370 and L<Catalyst::DispatchType::Chained|Catalyst::DispatchType::Chained>
371 for more information on chained actions.
375 You should refer to L<Catalyst::Manual::Intro/Action_types> for
376 additional information and for coverage of some lesser-used action
377 types not discussed here (C<Regex> and C<LocalRegex>).
380 =head1 CATALYST VIEWS
382 As mentioned in Part 2 of the tutorial, views are where you render
383 output, typically for display in the user's web browser (but also
384 possibly using other display output-generation systems). The code in
385 C<lib/MyApp/View> selects the I<type> of view to use, with the actual
386 rendering template found in the C<root> directory. As with virtually
387 every aspect of Catalyst, options abound when it comes to the specific
388 view technology you adopt inside your application. However, most
389 Catalyst applications use the Template Toolkit, known as TT (for more
390 information on TT, see L<http://www.template-toolkit.org>). Other
391 somewhat popular view technologies include Mason
392 (L<http://www.masonhq.com> and L<http://www.masonbook.com>) and
393 L<HTML::Template> (L<http://html-template.sourceforge.net>).
396 =head2 Create a Catalyst View
398 When using TT for the Catalyst view, there are two main helper scripts:
404 L<Catalyst::Helper::View::TT|Catalyst::Helper::View::TT>
408 L<Catalyst::Helper::View::TTSite|Catalyst::Helper::View::TTSite>
412 Both helpers are similar. C<TT> creates the C<lib/MyApp/View/TT.pm>
413 file and leaves the creation of any hierarchical template organization
414 entirely up to you. (It also creates a C<t/view_TT.t> file for testing;
415 test cases will be discussed in Part 8.) C<TTSite>, on the other hand,
416 creates a modular and hierarchical view layout with
417 separate Template Toolkit (TT) files for common header and footer
418 information, configuration values, a CSS stylesheet, and more.
420 While C<TTSite> was useful to bootstrap a project, its use is now
421 deprecated and to be considered historical. For most Catalyst
422 applications it adds redundant functionality and structure; many in the
423 Catalyst community recommend that it's easier to learn both Catalyst and
424 Template Toolkit if you use the more basic C<TT> approach.
425 Consequently, this tutorial will use "plain old TT."
427 Enter the following command to enable the C<TT> style of view
428 rendering for this tutorial:
430 $ script/myapp_create.pl view TT TT
431 exists "/home/me/MyApp/script/../lib/MyApp/View"
432 exists "/home/me/MyApp/script/../t"
433 created "/home/me/MyApp/script/../lib/MyApp/View/TT.pm"
434 created "/home/me/MyApp/script/../t/view_TT.t"
436 This simply creates a view called C<TT> (the second 'TT' argument) in
437 a file called C<TT.pm> (the first 'TT' argument). It is now up to you
438 to decide how you want to structure your view layout. For the
439 tutorial, we will start with a very simple TT template to initially
440 demonstrate the concepts, but quickly migrate to a more typical
441 "wrapper page" type of configuration (where the "wrapper" controls the
442 overall "look and feel" of your site from a single file or set of
445 Edit C<lib/MyApp/View/TT.pm> and you should see that the default
446 contents contains something similar to the following:
448 __PACKAGE__->config(TEMPLATE_EXTENSION => '.tt');
450 And update it to match:
453 # Change default TT extension
454 TEMPLATE_EXTENSION => '.tt2',
455 # Set the location for TT files
457 MyApp->path_to( 'root', 'src' ),
461 B<NOTE:> Make sure to add a comma after '.tt2' outside the single
464 This changes the default extension for Template Toolkit from '.tt' to
465 '.tt2' and changes the base directory for your template files from
466 C<root> to C<root/src>. These changes from the default are done mostly
467 to facilitate the application we're developing in this tutorial; as with
468 most things Perl, there's more than one way to do it...
471 =head2 Create a TT Template Page
473 First create a directory for book-related TT templates:
475 $ mkdir -p root/src/books
477 Then create C<root/src/books/list.tt2> in your editor and enter:
479 [% # This is a TT comment. The '-' at the end "chomps" the newline. You won't -%]
480 [% # see this "chomping" in your browser because HTML ignores blank lines, but -%]
481 [% # it WILL eliminate a blank line if you view the HTML source. It's purely -%]
482 [%- # optional, but both the beginning and the ending TT tags support chomping. -%]
484 [% # Provide a title -%]
485 [% META title = 'Book List' -%]
488 <tr><th>Title</th><th>Rating</th><th>Author(s)</th></tr>
489 [% # Display each book in a table row %]
490 [% FOREACH book IN books -%]
492 <td>[% book.title %]</td>
493 <td>[% book.rating %]</td>
498 As indicated by the inline comments above, the C<META title> line uses
499 TT's META feature to provide a title to the "wrapper" that we will
500 create later. Meanwhile, the C<FOREACH> loop iterates through each
501 C<book> model object and prints the C<title> and C<rating> fields.
503 If you are new to TT, the C<[%> and C<%]> tags are used to delimit TT
504 code. TT supports a wide variety of directives for "calling" other
505 files, looping, conditional logic, etc. In general, TT simplifies the
506 usual range of Perl operators down to the single dot (C<.>) operator.
507 This applies to operations as diverse as method calls, hash lookups, and
508 list index values (see
509 L<http://search.cpan.org/perldoc?Template::Manual::Variables>
510 for details and examples). In addition to the usual C<Template> module
511 Pod documentation, you can access the TT manual at
512 L<http://search.cpan.org/perldoc?Template::Manual>.
514 B<TIP:> While you can build all sorts of complex logic into your TT
515 templates, you should in general keep the "code" part of your templates
516 as simple as possible. If you need more complex logic, create helper
517 methods in your model that abstract out a set of code into a single call
518 from your TT template. (Note that the same is true of your controller
519 logic as well -- complex sections of code in your controllers should
520 often be pulled out and placed into your model objects.)
523 =head2 Test Run The Application
525 To test your work so far, first start the development server:
527 $ script/myapp_server.pl
529 Then point your browser to L<http://localhost:3000> and you should
530 still get the Catalyst welcome page. Next, change the URL in your
531 browser to L<http://localhost:3000/books/list>. If you have
532 everything working so far, you should see a web page that displays
533 nothing other than our column headers for "Title", "Rating", and
534 "Author(s)" -- we will not see any books until we get the database and
537 If you run into problems getting your application to run correctly, it
538 might be helpful to refer to some of the debugging techniques covered in
539 the L<Debugging|Catalyst::Manual::Tutorial::Debugging> part of the
543 =head1 CREATE A SQLITE DATABASE
545 In this step, we make a text file with the required SQL commands to
546 create a database table and load some sample data. We will use SQLite,
547 a popular database that is lightweight and easy to use. Open
548 C<myapp01.sql> in your editor and enter:
551 -- Create a very simple database to hold book and author information
554 id INTEGER PRIMARY KEY,
558 -- 'book_authors' is a many-to-many join table between books & authors
559 CREATE TABLE book_authors (
562 PRIMARY KEY (book_id, author_id)
564 CREATE TABLE authors (
565 id INTEGER PRIMARY KEY,
570 --- Load some sample data
572 INSERT INTO books VALUES (1, 'CCSP SNRS Exam Certification Guide', 5);
573 INSERT INTO books VALUES (2, 'TCP/IP Illustrated, Volume 1', 5);
574 INSERT INTO books VALUES (3, 'Internetworking with TCP/IP Vol.1', 4);
575 INSERT INTO books VALUES (4, 'Perl Cookbook', 5);
576 INSERT INTO books VALUES (5, 'Designing with Web Standards', 5);
577 INSERT INTO authors VALUES (1, 'Greg', 'Bastien');
578 INSERT INTO authors VALUES (2, 'Sara', 'Nasseh');
579 INSERT INTO authors VALUES (3, 'Christian', 'Degu');
580 INSERT INTO authors VALUES (4, 'Richard', 'Stevens');
581 INSERT INTO authors VALUES (5, 'Douglas', 'Comer');
582 INSERT INTO authors VALUES (6, 'Tom', 'Christiansen');
583 INSERT INTO authors VALUES (7, 'Nathan', 'Torkington');
584 INSERT INTO authors VALUES (8, 'Jeffrey', 'Zeldman');
585 INSERT INTO book_authors VALUES (1, 1);
586 INSERT INTO book_authors VALUES (1, 2);
587 INSERT INTO book_authors VALUES (1, 3);
588 INSERT INTO book_authors VALUES (2, 4);
589 INSERT INTO book_authors VALUES (3, 5);
590 INSERT INTO book_authors VALUES (4, 6);
591 INSERT INTO book_authors VALUES (4, 7);
592 INSERT INTO book_authors VALUES (5, 8);
594 Then use the following command to build a C<myapp.db> SQLite database:
596 $ sqlite3 myapp.db < myapp01.sql
598 If you need to create the database more than once, you probably want to
599 issue the C<rm myapp.db> command to delete the database before you use
600 the C<sqlite3 myapp.db E<lt> myapp01.sql> command.
602 Once the C<myapp.db> database file has been created and initialized, you
603 can use the SQLite command line environment to do a quick dump of the
608 Enter ".help" for instructions
609 sqlite> select * from books;
610 1|CCSP SNRS Exam Certification Guide|5
611 2|TCP/IP Illustrated, Volume 1|5
612 3|Internetworking with TCP/IP Vol.1|4
614 5|Designing with Web Standards|5
620 $ sqlite3 myapp.db "select * from books"
621 1|CCSP SNRS Exam Certification Guide|5
622 2|TCP/IP Illustrated, Volume 1|5
623 3|Internetworking with TCP/IP Vol.1|4
625 5|Designing with Web Standards|5
627 As with most other SQL tools, if you are using the full "interactive"
628 environment you need to terminate your SQL commands with a ";" (it's not
629 required if you do a single SQL statement on the command line). Use
630 ".q" to exit from SQLite from the SQLite interactive mode and return to
631 your OS command prompt.
633 For using other databases, such as PostgreSQL or MySQL, see
634 L<Appendix 2|Catalyst::Manual::Tutorial::Appendices>.
636 =head1 DATABASE ACCESS WITH C<DBIx::Class>
638 Catalyst can be used with virtually any form of persistent datastore
639 available via Perl. For example,
640 L<Catalyst::Model::DBI|Catalyst::Model::DBI> can be used to easily
641 access databases through the traditional Perl C<DBI> interface. However,
642 most Catalyst applications use some form of ORM technology to
643 automatically create and save model objects as they are used. Although
644 L<Class::DBI|Class::DBI> has been a popular choice in the past, Matt
645 Trout's L<DBIx::Class|DBIx::Class> (abbreviated as "DBIC") has rapidly
646 emerged as the Perl-based ORM technology of choice. Most new Catalyst
647 applications rely on DBIC, as will this tutorial.
650 =head2 Create a Dynamic DBIC Model
652 Use the C<create=dynamic> model helper option to build a model that
653 dynamically reads your database structure every time the application
656 $ script/myapp_create.pl model DB DBIC::Schema MyApp::Schema create=dynamic dbi:SQLite:myapp.db
657 exists "/home/me/MyApp/script/../lib/MyApp/Model"
658 exists "/home/me/MyApp/script/../t"
659 exists "/home/me/MyApp/script/../lib/MyApp"
660 created "/home/me/MyApp/script/../lib/MyApp/Schema.pm"
661 created "/home/me/MyApp/script/../lib/MyApp/Model/DB.pm"
662 created "/home/me/MyApp/script/../t/model_DB.t"
665 C<DB> is the name of the model class to be created by the helper in
666 C<lib/MyApp/Model>. C<DBIC::Schema> is the type of the model to
667 create. C<MyApp::Schema> is the name of the DBIC schema file written
668 to C<lib/MyApp/Schema.pm>. Because we specified C<create=dynamic> to
670 L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> to
671 dynamically load the schema information from the database every time
672 the application starts. DBIC uses the schema to load other classes
673 that represent the tables in your database (DBIC refers to these
674 "table objects" as "result sources," see
675 L<DBIx::Class::ResultSource|DBIx::Class::ResultSource>). And finally,
676 C<dbi:SQLite:myapp.db> is the standard DBI connect string for use with
679 B<NOTE:> Although the C<create=dynamic> option to the DBIC helper
680 makes for a nifty demonstration, is only really suitable for very
681 small applications. After this demonstration, you should almost always
682 use the C<create=static> option that we switch to below.
685 =head1 ENABLE THE MODEL IN THE CONTROLLER
687 Open C<lib/MyApp/Controller/Books.pm> and un-comment the model code we
688 left disabled earlier (un-comment the line containing
689 C<[$c-E<gt>model('DB::Books')-E<gt>all]> and delete the next 2 lines):
693 Fetch all book objects and pass to books/list.tt2 in stash to be displayed
698 # Retrieve the usual Perl OO '$self' for this object. $c is the Catalyst
699 # 'Context' that's used to 'glue together' the various components
700 # that make up the application
703 # Retrieve all of the book records as book model objects and store in the
704 # stash where they can be accessed by the TT template
705 $c->stash->{books} = [$c->model('DB::Books')->all];
707 # Set the TT template to use. You will almost always want to do this
708 # in your action methods (action methods respond to user input in
710 $c->stash->{template} = 'books/list.tt2';
713 B<TIP>: You may see the C<$c-E<gt>model('DB::Book')> un-commented
714 above written as C<$c-E<gt>model('DB')-E<gt>resultset('Book')>. The
715 two are equivalent. Either way, C<$c-E<gt>model> returns a
716 L<DBIx::Class::ResultSet|DBIx::Class::ResultSet> which handles queries
717 against the database and iterating over the set of results that are
720 We are using the C<-E<gt>all> to fetch all of the books. DBIC
721 supports a wide variety of more advanced operations to easily do
722 things like filtering and sorting the results. For example, the
723 following could be used to sort the results by descending title:
725 $c->model('DB::Books')->search({}, {order_by => 'title DESC'});
727 Some other examples are provided in
728 L<DBIx::Class::Manual::Cookbook/Complex WHERE clauses>, with
729 additional information found at L<DBIx::Class::ResultSet/search>,
730 L<DBIx::Class::Manual::FAQ/Searching>,
731 L<DBIx::Class::Manual::Intro|DBIx::Class::Manual::Intro>
732 and L<Catalyst::Model::DBIC::Schema|Catalyst::Model::DBIC::Schema>.
735 =head2 Test Run The Application
737 First, let's enable an environment variable option that causes
738 DBIx::Class to dump the SQL statements it's using to access the database
739 (this option can provide extremely helpful troubleshooting information):
741 $ export DBIC_TRACE=1
743 This assumes you are using BASH as your shell -- adjust accordingly if
744 you are using a different shell (for example, under tcsh, use
745 C<setenv DBIC_TRACE 1>).
747 B<NOTE:> You can also set this in your code using
748 C<$class-E<gt>storage-E<gt>debug(1);>. See
749 L<DBIx::Class::Manual::Troubleshooting> for details (including options
750 to log to file instead of displaying to the Catalyst development server
753 Then launch the Catalyst development server. The log output should
754 display something like:
756 $script/myapp_server.pl
757 [debug] Debug messages enabled
758 [debug] Statistics enabled
759 [debug] Loaded plugins:
760 .----------------------------------------------------------------------------.
761 | Catalyst::Plugin::ConfigLoader 0.20 |
762 | Catalyst::Plugin::StackTrace 0.08 |
763 | Catalyst::Plugin::Static::Simple 0.20 |
764 '----------------------------------------------------------------------------'
766 [debug] Loaded dispatcher "Catalyst::Dispatcher"
767 [debug] Loaded engine "Catalyst::Engine::HTTP"
768 [debug] Found home "/home/me/MyApp"
769 [debug] Loaded Config "/home/me/MyApp/myapp.conf"
770 [debug] Loaded components:
771 .-----------------------------------------------------------------+----------.
773 +-----------------------------------------------------------------+----------+
774 | MyApp::Controller::Books | instance |
775 | MyApp::Controller::Root | instance |
776 | MyApp::Model::DB | instance |
777 | MyApp::Model::DB::Authors | class |
778 | MyApp::Model::DB::BookAuthors | class |
779 | MyApp::Model::DB::Books | class |
780 | MyApp::View::TT | instance |
781 '-----------------------------------------------------------------+----------'
783 [debug] Loaded Private actions:
784 .----------------------+--------------------------------------+--------------.
785 | Private | Class | Method |
786 +----------------------+--------------------------------------+--------------+
787 | /default | MyApp::Controller::Root | default |
788 | /end | MyApp::Controller::Root | end |
789 | /index | MyApp::Controller::Root | index |
790 | /books/index | MyApp::Controller::Books | index |
791 | /books/list | MyApp::Controller::Books | list |
792 '----------------------+--------------------------------------+--------------'
794 [debug] Loaded Path actions:
795 .-------------------------------------+--------------------------------------.
797 +-------------------------------------+--------------------------------------+
800 | /books | /books/index |
801 | /books/list | /books/list |
802 '-------------------------------------+--------------------------------------'
804 [info] MyApp powered by Catalyst 5.7014
805 You can connect to your server at http://localhost:3000
807 B<NOTE:> Be sure you run the C<script/myapp_server.pl> command from
808 the 'base' directory of your application, not inside the C<script>
809 directory itself or it will not be able to locate the C<myapp.db>
810 database file. You can use a fully qualified or a relative path to
811 locate the database file, but we did not specify that when we ran the
812 model helper earlier.
814 Some things you should note in the output above:
820 Catalyst::Model::DBIC::Schema dynamically created three model classes,
821 one to represent each of the three tables in our database
822 (C<MyApp::Model::DB::Authors>, C<MyApp::Model::DB::BookAuthors>,
823 and C<MyApp::Model::DB::Books>).
827 The "list" action in our Books controller showed up with a path of
832 Point your browser to L<http://localhost:3000> and you should still get
833 the Catalyst welcome page.
835 Next, to view the book list, change the URL in your browser to
836 L<http://localhost:3000/books/list>. You should get a list of the five
837 books loaded by the C<myapp01.sql> script above without any formatting.
838 The rating for each book should appear on each row, but the "Author(s)"
839 column will still be blank (we will fill that in later).
841 Also notice in the output of the C<script/myapp_server.pl> that DBIC
842 used the following SQL to retrieve the data:
844 SELECT me.id, me.title, me.rating FROM books me
846 because we enabled DBIC_TRACE.
848 You now have the beginnings of a simple but workable web application.
849 Continue on to future sections and we will develop the application
853 =head1 CREATE A WRAPPER FOR THE VIEW
855 When using TT, you can (and should!) create a wrapper that will
856 literally wrap content around each of your templates. This is
857 certainly useful as you have one main source for changing things that
858 will appear across your entire site/application instead of having to
859 edit many individual files.
862 =head2 Configure TT.pm For The Wrapper
864 In order to create a wrapper, you must first edit your TT view and
865 tell it where to find your wrapper file. Your TT view is located in
866 C<lib/MyApp/View/TT.pm>.
868 Edit C<lib/MyApp/View/TT.pm> and change it to match the following:
871 # Change default TT extension
872 TEMPLATE_EXTENSION => '.tt2',
873 # Set the location for TT files
875 MyApp->path_to( 'root', 'src' ),
877 # Set to 1 for detailed timer stats in your HTML as comments
879 # This is your wrapper template located in the 'root/src'
880 WRAPPER => 'wrapper.tt2',
884 =head2 Create the Wrapper Template File and Stylesheet
886 Next you need to set up your wrapper template. Basically, you'll want
887 to take the overall layout of your site and put it into this file.
888 For the tutorial, open C<root/src/wrapper.tt2> and input the following:
890 <?xml version="1.0" encoding="UTF-8"?>
891 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
892 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
894 <title>[% template.title or "My Catalyst App!" %]</title>
895 <link rel="stylesheet" href="[% c.uri_for('/static/css/main.css') %]" />
901 [%# Your logo could go here -%]
902 <img src="[% c.uri_for('/static/images/btn_88x31_powered.png') %]" />
903 [%# Insert the page title -%]
904 <h1>[% template.title or site.title %]</h1>
911 <li><a href="[% c.uri_for('/books/list') %]">Home</a></li>
912 <li><a href="[% c.uri_for('/') %]" title="Catalyst Welcome Page">Welcome</a></li>
913 <li><a href="mailto:nobody@nowhere.com" title="Contact Us">Contact Us</a></li>
915 </div><!-- end menu -->
918 [%# Status and error messages %]
919 <span class="message">[% status_msg %]</span>
920 <span class="error">[% error_msg %]</span>
921 [%# This is where TT will stick all of your template's contents. -%]
923 </div><!-- end content -->
924 </div><!-- end bodyblock -->
926 <div id="footer">Copyright (c) your name goes here</div>
927 </div><!-- end outer -->
932 Notice the status and error message sections in the code above:
934 <span class="status">[% status_msg %]</span>
935 <span class="error">[% error_msg %]</span>
937 If we set either message in the Catalyst stash (e.g.,
938 C<$c-E<gt>stash-E<gt>{status_msg} = 'Request was successful!'>) it
939 will be displayed whenever any view used by that request is rendered.
940 The C<message> and C<error> CSS styles can be customized to suit your
941 needs in the C<root/static/css/main.css> file we create below.
949 The Catalyst stash only lasts for a single HTTP request. If
950 you need to retain information across requests you can use
951 L<Catalyst::Plugin::Session|Catalyst::Plugin::Session> (we will use
952 Catalyst sessions in the Authentication part of the tutorial).
956 Although it is beyond the scope of this tutorial, you may wish to use
957 a JavaScript or AJAX tool such as jQuery (L<http://www.jquery.com>) or
958 Dojo (L<http://www.dojotoolkit.org>).
963 =head3 Create A Basic Stylesheet
965 First create a central location for stylesheets under the static
968 $ mkdir root/static/css
970 Then open the file C<root/static/css/main.css> (the file referenced in
971 the stylesheet href link of our wrapper above) and add the following
990 background-color: #ddd;
996 padding: 0 0 50% 5px;
998 background-color: #ddd;
1011 You may wish to check out a "CSS Framework" like Emastic
1012 (L<http://code.google.com/p/emastic/>) as a way to quickly
1013 provide lots of high-quality CSS functionality.
1016 =head2 Test Run The Application
1018 Restart the development server and hit "Reload" in your web browser
1019 and you should now see a formatted version of our basic book list.
1020 Although our wrapper and stylesheet are obviously very simple, you
1021 should see how it allows us to control the overall look of an entire
1022 website from two central files. To add new pages to the site, just
1023 provide a template that fills in the C<content> section of our wrapper
1024 template -- the wrapper will provide the overall feel of the page.
1027 =head1 A STATIC DATABASE MODEL WITH C<DBIx::Class>
1029 =head2 Create Static DBIC Schema Files
1031 Unlike the previous DBIC section where we had C<create=dynamic>
1032 automatically discover the structure of the database every time the
1033 application started, here we will use static schema files for more
1034 control. This is typical of most "real world" applications.
1036 One option would be to manually create a separate schema file for each
1037 table in the database, however, lets use the same
1038 L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> used
1039 earlier with C<create=dynamic> to build the static files for us.
1040 First, lets remove the schema file created earlier:
1042 $ rm lib/MyApp/Schema.pm
1044 Now regenerate the schema using the C<create=static> option:
1046 $ script/myapp_create.pl model DB DBIC::Schema MyApp::Schema create=static dbi:SQLite:myapp.db
1047 exists "/home/kclark/dev/MyApp/script/../lib/MyApp/Model"
1048 exists "/home/kclark/dev/MyApp/script/../t"
1049 Dumping manual schema for MyApp::Schema to directory /home/kclark/dev/MyApp/script/../lib ...
1050 Schema dump completed.
1051 exists "/home/kclark/dev/MyApp/script/../lib/MyApp/Model/DB.pm"
1053 We could have also deleted C<lib/MyApp/Model/DB.pm>, but it would
1054 have regenerated the same file (note the C<exists> in the output above).
1055 If you take a look at C<lib/MyApp/Model/DB.pm>, it simply contains
1056 a reference to the actual schema file in C<lib/MyApp/Schema.pm>
1057 along with the database connect string.
1059 If you look in the C<lib/MyApp/Schema.pm> file, you will find that it
1061 L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> as its base
1062 class (L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> is
1063 only being used by the helper to load the schema once and then create
1064 the static files for us) and C<Schema.pm> only contains a call to the
1065 C<load_classes> method. You will also find that C<lib/MyApp>
1066 contains a C<Schema> subdirectory, with one file inside this directory
1067 for each of the tables in our simple database (C<Authors.pm>,
1068 C<BookAuthors.pm>, and C<Books.pm>). These three files were created
1069 based on the information found by
1070 L<DBIx::Class::Schema::Loader|DBIx::Class::Schema::Loader> as the
1073 The idea with all of the files created under C<lib/MyApp/Schema> by
1074 the C<create=static> option is to only edit the files below the C<# DO
1075 NOT MODIFY THIS OR ANYTHING ABOVE!> warning. If you place all of your
1076 changes below that point in the file, you can regenerate the
1077 automatically created information at the top of each file should your
1078 database structure get updated.
1080 Also note the "flow" of the model information across the various files
1081 and directories. Catalyst will initially load the model from
1082 C<lib/MyApp/Model/DB.pm>. This file contains a reference to
1083 C<lib/MyApp/Schema.pm>, so that file is loaded next. Finally,
1084 the call to C<load_classes> in C<Schema.pm> will load each of the
1085 table-specific "results source" files from the C<lib/MyApp/Schema>
1086 subdirectory. These three table-specific DBIC schema files will then be
1087 used to create three table-specific Catalyst models every time the
1088 application starts (you can see these three model files listed in
1089 the debug output generated when you launch the application).
1092 =head2 Updating the Generated DBIC Schema Files
1094 Let's manually add some relationship information to the auto-generated
1095 schema files. First edit C<lib/MyApp/Schema/Books.pm> and
1096 add the following text below the C<# You can replace this text...>
1100 # Set relationships:
1105 # 1) Name of relationship, DBIC will create accessor with this name
1106 # 2) Name of the model class referenced by this relationship
1107 # 3) Column name in *foreign* table
1108 __PACKAGE__->has_many(book_authors => 'MyApp::Schema::BookAuthors', 'book_id');
1112 # 1) Name of relationship, DBIC will create accessor with this name
1113 # 2) Name of has_many() relationship this many_to_many() is shortcut for
1114 # 3) Name of belongs_to() relationship in model class of has_many() above
1115 # You must already have the has_many() defined to use a many_to_many().
1116 __PACKAGE__->many_to_many(authors => 'book_authors', 'author');
1119 B<Note:> Be careful to put this code I<above> the C<1;> at the end of the
1120 file. As with any Perl package, we need to end the last line with
1121 a statement that evaluates to C<true>. This is customarily done with
1122 C<1;> on a line by itself.
1124 This code defines both a C<has_many> and a C<many_to_many> relationship.
1125 The C<many_to_many> relationship is optional, but it makes it easier to
1126 map a book to its collection of authors. Without it, we would have to
1127 "walk" though the C<book_authors> table as in
1128 C<$book-E<gt>book_authors-E<gt>first-E<gt>author-E<gt>last_name>
1129 (we will see examples on how to use DBIC objects in your code soon,
1130 but note that because C<$book-E<gt>book_authors> can return multiple
1131 authors, we have to use C<first> to display a single author).
1132 C<many_to_many> allows us to use the shorter
1133 C<$book-E<gt>authors-E<gt>first-E<gt>last_name>.
1134 Note that you cannot define a C<many_to_many> relationship without
1135 also having the C<has_many> relationship in place.
1137 Then edit C<lib/MyApp/Schema/Authors.pm> and add relationship
1138 information as follows (again, be careful to put in above the C<1;> but
1139 below the C<# DO NOT MODIFY THIS OR ANYTHING ABOVE!> comment):
1142 # Set relationships:
1147 # 1) Name of relationship, DBIC will create accessor with this name
1148 # 2) Name of the model class referenced by this relationship
1149 # 3) Column name in *foreign* table
1150 __PACKAGE__->has_many(book_author => 'MyApp::Schema::BookAuthors', 'author_id');
1154 # 1) Name of relationship, DBIC will create accessor with this name
1155 # 2) Name of has_many() relationship this many_to_many() is shortcut for
1156 # 3) Name of belongs_to() relationship in model class of has_many() above
1157 # You must already have the has_many() defined to use a many_to_many().
1158 __PACKAGE__->many_to_many(books => 'book_author', 'book');
1160 Finally, do the same for the "join table,"
1161 C<lib/MyApp/Schema/BookAuthors.pm>:
1164 # Set relationships:
1169 # 1) Name of relationship, DBIC will create accessor with this name
1170 # 2) Name of the model class referenced by this relationship
1171 # 3) Column name in *this* table
1172 __PACKAGE__->belongs_to(book => 'MyApp::Schema::Books', 'book_id');
1176 # 1) Name of relationship, DBIC will create accessor with this name
1177 # 2) Name of the model class referenced by this relationship
1178 # 3) Column name in *this* table
1179 __PACKAGE__->belongs_to(author => 'MyApp::Schema::Authors', 'author_id');
1182 =head2 Run The Application
1184 Run the Catalyst "demo server" script with the C<DBIC_TRACE> option
1185 (it might still be enabled from earlier in the tutorial, but here
1186 is an alternate way to specify the option just in case):
1188 $ DBIC_TRACE=1 script/myapp_server.pl
1190 Make sure that the application loads correctly and that you see the
1191 three dynamically created model class (one for each of the
1192 table-specific schema classes we created).
1194 Then hit the URL L<http://localhost:3000/books/list> and be sure that
1195 the book list is displayed via the relationships established above. You
1196 can leave the development server running for the next step if you wish.
1198 B<Note:> You will not see the authors yet because the view does not yet
1199 use the new relations. Read on to the next section where we update the
1200 template to do that.
1203 =head1 UPDATING THE VIEW
1205 Let's add a new column to our book list page that takes advantage of
1206 the relationship information we manually added to our schema files
1207 in the previous section. Edit C<root/src/books/list.tt2> add add the
1208 following code below the existing table cell that contains
1209 C<book.rating> (IOW, add a new table cell below the existing two
1213 [% # First initialize a TT variable to hold a list. Then use a TT FOREACH -%]
1214 [% # loop in 'side effect notation' to load just the last names of the -%]
1215 [% # authors into the list. Note that the 'push' TT vmethod does not print -%]
1216 [% # a value, so nothing will be printed here. But, if you have something -%]
1217 [% # in TT that does return a method and you don't want it printed, you -%]
1218 [% # can: 1) assign it to a bogus value, or 2) use the CALL keyword to -%]
1219 [% # call it and discard the return value. -%]
1220 [% tt_authors = [ ];
1221 tt_authors.push(author.last_name) FOREACH author = book.authors %]
1222 [% # Now use a TT 'virtual method' to display the author count in parens -%]
1223 [% # Note the use of the TT filter "| html" to escape dangerous characters -%]
1224 ([% tt_authors.size | html %])
1225 [% # Use another TT vmethod to join & print the names & comma separators -%]
1226 [% tt_authors.join(', ') | html %]
1229 Then hit "Reload" in your browser (note that you don't need to reload
1230 the development server or use the C<-r> option when updating TT
1231 templates) and you should now see the number of authors each book has
1232 along with a comma-separated list of the authors' last names. (If you
1233 didn't leave the development server running from the previous step,
1234 you will obviously need to start it before you can refresh your
1237 If you are still running the development server with C<DBIC_TRACE>
1238 enabled, you should also now see five more C<SELECT> statements in the
1239 debug output (one for each book as the authors are being retrieved by
1242 SELECT me.id, me.title, me.rating FROM books me:
1243 SELECT me.book_id, me.author_id FROM book_authors me WHERE ( me.book_id = ? ): '1'
1244 SELECT me.book_id, me.author_id FROM book_authors me WHERE ( me.book_id = ? ): '2'
1245 SELECT me.book_id, me.author_id FROM book_authors me WHERE ( me.book_id = ? ): '3'
1246 SELECT me.book_id, me.author_id FROM book_authors me WHERE ( me.book_id = ? ): '4'
1247 SELECT me.book_id, me.author_id FROM book_authors me WHERE ( me.book_id = ? ): '5'
1249 Also note in C<root/src/books/list.tt2> that we are using "| html", a
1250 type of TT filter, to escape characters such as E<lt> and E<gt> to <
1251 and > and avoid various types of dangerous hacks against your
1252 application. In a real application, you would probably want to put
1253 "| html" at the end of every field where a user has control over the
1254 information that can appear in that field (and can therefore inject
1255 markup or code if you don't "neutralize" those fields). In addition to
1256 "| html", Template Toolkit has a variety of other useful filters that
1257 can found in the documentation for
1258 L<Template::Filters|Template::Filters>.
1261 =head1 RUNNING THE APPLICATION FROM THE COMMAND LINE
1263 In some situations, it can be useful to run your application and
1264 display a page without using a browser. Catalyst lets you do this
1265 using the C<scripts/myapp_test.pl> script. Just supply the URL you
1266 wish to display and it will run that request through the normal
1267 controller dispatch logic and use the appropriate view to render the
1268 output (obviously, complex pages may dump a lot of text to your
1269 terminal window). For example, if you type:
1271 $ script/myapp_test.pl "/books/list"
1273 You should get the same text as if you visited
1274 L<http://localhost:3000/books/list> with the normal development server
1275 and asked your browser to view the page source.
1278 =head1 OPTIONAL INFORMATION
1280 B<NOTE: The rest of this part of the tutorial is optional. You can
1281 skip to Part 4, L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD>,
1284 =head2 Using C<RenderView> for the Default View
1286 Once your controller logic has processed the request from a user, it
1287 forwards processing to your view in order to generate the appropriate
1288 response output. Catalyst uses
1289 L<Catalyst::Action::RenderView|Catalyst::Action::RenderView> by
1290 default to automatically performs this operation. If you look in
1291 C<lib/MyApp/Controller/Root.pm>, you should see the empty
1292 definition for the C<sub end> method:
1294 sub end : ActionClass('RenderView') {}
1296 The following bullet points provide a quick overview of the
1297 C<RenderView> process:
1303 C<Root.pm> is designed to hold application-wide logic.
1307 At the end of a given user request, Catalyst will call the most specific
1308 C<end> method that's appropriate. For example, if the controller for a
1309 request has an C<end> method defined, it will be called. However, if
1310 the controller does not define a controller-specific C<end> method, the
1311 "global" C<end> method in C<Root.pm> will be called.
1315 Because the definition includes an C<ActionClass> attribute, the
1316 L<Catalyst::Action::RenderView|Catalyst::Action::RenderView> logic
1317 will be executed B<after> any code inside the definition of C<sub end>
1318 is run. See L<Catalyst::Manual::Actions|Catalyst::Manual::Actions>
1319 for more information on C<ActionClass>.
1323 Because C<sub end> is empty, this effectively just runs the default
1324 logic in C<RenderView>. However, you can easily extend the
1325 C<RenderView> logic by adding your own code inside the empty method body
1326 (C<{}>) created by the Catalyst Helpers when we first ran the
1327 C<catalyst.pl> to initialize our application. See
1328 L<Catalyst::Action::RenderView|Catalyst::Action::RenderView> for more
1329 detailed information on how to extended C<RenderView> in C<sub end>.
1334 =head2 Using The Default Template Name
1336 By default, C<Catalyst::View::TT> will look for a template that uses the
1337 same name as your controller action, allowing you to save the step of
1338 manually specifying the template name in each action. For example, this
1339 would allow us to remove the
1340 C<$c-E<gt>stash-E<gt>{template} = 'books/list.tt2';> line of our
1341 C<list> action in the Books controller. Open
1342 C<lib/MyApp/Controller/Books.pm> in your editor and comment out this line
1343 to match the following (only the C<$c-E<gt>stash-E<gt>{template}> line
1348 Fetch all book objects and pass to books/list.tt2 in stash to be displayed
1353 # Retrieve the usual Perl OO '$self' for this object. $c is the Catalyst
1354 # 'Context' that's used to 'glue together' the various components
1355 # that make up the application
1356 my ($self, $c) = @_;
1358 # Retrieve all of the book records as book model objects and store in the
1359 # stash where they can be accessed by the TT template
1360 $c->stash->{books} = [$c->model('DB::Books')->all];
1362 # Set the TT template to use. You will almost always want to do this
1363 # in your action methods (actions methods respond to user input in
1364 # your controllers).
1365 #$c->stash->{template} = 'books/list.tt2';
1369 You should now be able to restart the development server as per the
1370 previous section and access the L<http://localhost:3000/books/list>
1373 B<NOTE:> Please note that if you use the default template technique,
1374 you will B<not> be able to use either the C<$c-E<gt>forward> or
1375 the C<$c-E<gt>detach> mechanisms (these are discussed in Part 2 and
1376 Part 9 of the Tutorial).
1379 =head2 Return To A Manually-Specified Template
1381 In order to be able to use C<$c-E<gt>forward> and C<$c-E<gt>detach>
1382 later in the tutorial, you should remove the comment from the
1383 statement in C<sub list> in C<lib/MyApp/Controller/Books.pm>:
1385 $c->stash->{template} = 'books/list.tt2';
1387 Then delete the C<TEMPLATE_EXTENSION> line in
1388 C<lib/MyApp/View/TT.pm>.
1390 You should then be able to restart the development server and
1391 access L<http://localhost:3000/books/list> in the same manner as
1392 with earlier sections.
1397 Kennedy Clark, C<hkclark@gmail.com>
1399 Please report any errors, issues or suggestions to the author. The
1400 most recent version of the Catalyst Tutorial can be found at
1401 L<http://dev.catalyst.perl.org/repos/Catalyst/Catalyst-Manual/5.70/trunk/lib/Catalyst/Manual/Tutorial/>.
1403 Copyright 2006-2008, Kennedy Clark, under Creative Commons License
1404 (L<http://creativecommons.org/licenses/by-sa/3.0/us/>).