INSERT INTO book_authors VALUES (5, 8);
B<TIP>: See Appendix 1 for tips on removing the leading spaces when
-cutting and pasting example code from POD documents.
+cutting and pasting example code from POD-based documents.
Then use the following command to build a C<myapp.db> SQLite database:
As you may have noticed, C<-Debug> is not a plugin, but a I<flag>.
Although most of the items specified on the C<use Catalyst> line of your
application class will be plugins, Catalyst supports a limited number of
-flag options (of these, C<-Debug> is the most common).
+flag options (of these, C<-Debug> is the most common). See the
+documentation for C<Catalyst.pm> to get details on other flags
+(currently C<-Engine>, C<-Home>, and C<-Log>).
If you prefer, you can use the C<$c-E<gt>debug> method to enable debug
messages.
=item *
-L<Catalyst::Plugin::Static::Simple>
+L<Catalyst::Plugin::Static::Simple|Catalyst::Plugin::Static::Simple>
C<Static::Simple> provides an easy method of serving static content such
as images and CSS files under the development server.
Static::Simple
StackTrace
- DefaultEnd
/;
-This tells Catalyst to start using three new plugins:
+This tells Catalyst to start using one new plugin:
=over 4
browser, not in the console window from which you're running your
application, which is where logging output usually goes.
-=item *
-
-L<Catalyst::Plugin::DefaultEnd|Catalyst::Plugin::DefaultEnd>
-
-Automatically provides a Catalyst "end action" that invokes your view at
-the end of each request. Also allows you to add "dump_info=1" (precede
-with "?" or "&" depending on where it is in the URL) to I<force> the
-debug screen at the end of the Catalyst request processing cycle.
-
-B<TIP>: Many Catalyst-related documents predate
-L<DefaultEnd|Catalyst::Plugin::DefaultEnd> and suggest that you add an
-C<end> action to your application class (C<MyApp.pm>) or Root.pm
-(C<MyApp/Controller/Root.pm>). In most of these cases, you can convert
-to L<DefaultEnd|Catalyst::Plugin::DefaultEnd> by deleting the C<end>
-action and using the plugin instead. There are certainly cases when
-you'd want to write your own custom C<end> action, but for most
-circumstances, DefaultEnd will be exactly what you want.
-
=back
Note that when specifying plugins on the C<use Catalyst> line, you can
the plugin names across multiple lines as shown here, or place them all
on one (or more) lines as with the default configuration.
+B<TIP:> You may see examples that include the
+L<Catalyst::Plugin::DefaultEnd|Catalyst::Plugin::DefaultEnd>
+plugins. As of Catalyst 5.7000, C<DefaultEnd> has been
+deprecated in favor of
+L<Catalyst::Action::RenderView|Catalyst::Action::RenderView>
+(as the name of the package suggests, C<RenderView> is not
+a plugin, but an action). The purpose of both is essentially the same:
+forward processing to the view to be rendered. For more information
+on C<RenderView> and the various options for forwarding to your view
+logic, please refer to the "Enable RenderView for the Default View"
+section under "CATALYST VIEWS" below.
+
+
+
=head1 DATABASE ACCESS WITH C<DBIx::Class>
Catalyst can be used with virtually any form of persistent datastore
-available via Perl. For example, L<Catalyst::Model::DBI> can be used to
-easily access databases through the traditional Perl L<DBI> interface.
+available via Perl. For example,
+L<Catalyst::Model::DBI|Catalyst::Model::DBI> can be used to
+easily access databases through the traditional Perl C<DBI> interface.
However, most Catalyst applications use some form of ORM technology to
automatically create and save model objects as they are used. Although
-Tony Bowden's L<Class::DBI> has been the traditional Perl ORM engine,
-Matt Trout's L<DBIx::Class> (abbreviated as "DBIC") has rapidly emerged
-as the Perl-based ORM technology of choice. Most new Catalyst
-applications rely on DBIC, as will this tutorial.
+Tony Bowden's L<Class::DBI|Class::DBI> has been the traditional
+Perl ORM engine, Matt Trout's L<DBIx::Class|DBIx::Class> (abbreviated
+as "DBIC") has rapidly emerged as the Perl-based ORM technology of choice.
+Most new Catalyst applications rely on DBIC, as will this tutorial.
-Note: See L<Catalyst:: Model::CDBI > for more information on using
-Catalyst with L<Class::DBI>.
+Note: See L<Catalyst:: Model::CDBI> for more information on using
+Catalyst with L<Class::DBI|Class::DBI>.
=head2 Create a DBIC Schema File
B<Note:> C<__PACKAGE__> is just a shorthand way of referencing the name
of the package where it is used. Therefore, in C<MyAppDB.pm>,
-C<__PACKAGE__> is equivalent to C<MyAppDB>
+C<__PACKAGE__> is equivalent to C<MyAppDB>.
=head2 Create the DBIC "Result Source" Files
=head2 Use C<Catalyst::Model::DBIC::Schema> To Load The Model Class
-When L<Catalyst::Model::DBIC::Schema> is
+When L<Catalyst::Model::DBIC::Schema|Catalyst::Model::DBIC::Schema> is
in use, Catalyst essentially reads an existing copy of your database
model and creates a new set of objects under C<MyApp::Model> for use
inside of Catalyst.
-B<Note:> With L<Catalyst::Model::DBIC::Schema> you essentially end up
-with two sets of model classes (only one of which you write... the other
-set is created automatically in memory when your Catalyst application
-initializes). For this tutorial application, the important points to
-remember are: you write the I<result source> files in C<MyAppDB>, but
-I<within Catalyst> you use the I<automatically created model classes> in
-C<MyApp::Model>.
+B<Note:> With
+L<Catalyst::Model::DBIC::Schema|Catalyst::Model::DBIC::Schema> you
+essentially end up with two sets of model classes (only one of which
+you write... the other set is created automatically in memory when
+your Catalyst application initializes). For this tutorial application,
+the important points to remember are: you write the I<result source>
+files in C<MyAppDB>, but I<within Catalyst> you use the I<automatically
+created model classes> in C<MyApp::Model>.
-Use the L<Catalyst::Helper::Model::DBIC::Schema > helper script to
-create the model class that loads up the model we created in the
-previous step:
+Use the
+L<Catalyst::Helper::Model::DBIC::Schema|Catalyst::Helper::Model::DBIC::Schema>
+helper script to create the model class that loads up the model we
+created in the previous step:
$ script/myapp_create.pl model MyAppDB DBIC::Schema MyAppDB dbi:SQLite:myapp.db '' '' '{ AutoCommit => 1 }'
are equivalent.
B<Note:> Catalyst actions are regular Perl methods, but they make use of
-Nicholas Clark's C<attributes> module to provide additional information
-to the Catalyst dispatcher logic.
+Nicholas Clark's C<attributes> module (that's the C<: Local> next to the
+C<sub list> in the code above) to provide additional information to the
+Catalyst dispatcher logic.
=head1 CATALYST VIEWS
Views are where you render output, typically for display in the user's
-web browser, but also possibly using other display our output-generation
+web browser, but also possibly using other display output-generation
systems. As with virtually every aspect of Catalyst, options abound
when it comes to the specific view technology you adopt inside your
application. However, most Catalyst applications use the Template
Toolkit, known as TT (for more information on TT, see
L<http://www.template-toolkit.org>). Other popular View technologies
include Mason (L<http://www.masonhq.com> and
-L<http://www.masonbook.com>) and L<HTML::Template>
+L<http://www.masonbook.com>) and L<HTML::Template|HTML::Template>
(L<http://html-template.sourceforge.net>).
=head2 Create a Catalyst View Using C<TTSITE>
=item *
-L<Catalyst::Helper::View::TT>
+L<Catalyst::Helper::View::TT|Catalyst::Helper::View::TT>
=item *
-L<Catalyst::Helper::View::TTSite>
+L<Catalyst::Helper::View::TTSite|Catalyst::Helper::View::TTSite>
=back
looking at other Catalyst examples, remember that they almost always use
C<c>. Note that Catalyst and TT I<do not complain> when you use the
wrong name to access the context object...TT simply outputs blanks for
-that bogus logic. Finally, be aware that this change in name I<only>
+that bogus logic (see next tip to change this behavior with TT C<DEBUG>
+options). Finally, be aware that this change in name I<only>
applies to how the context object is accessed inside your TT templates;
your controllers will continue to use C<$c> (or whatever name you use
when fetching the reference from C<@_> inside your methods). (You can
careful not to have a collision between your own C<c> variable and the
Catalyst C<c> variable.)
+B<TIP>: When troubleshooting TT it can be helpful to enable variable
+C<DEBUG> options. You can do this in a Catalyst environment by adding
+a C<DEBUG> line to the C<__PACKAGE__->config> declaration in
+C<MyApp/View/TT.pm>:
+
+ __PACKAGE__->config({
+ CATALYST_VAR => 'Catalyst',
+ ...
+ DEBUG => 'undef',
+ ...
+ });
+
+There are a variety of options you can use, such as 'undef', 'all',
+'service', 'context', 'parser', 'provider', and 'service'. See
+L<Template::Constants> for more information (remove the C<DEBUG_>
+portion of the name shown in the TT docs and convert to lower case
+for use inside Catalyst).
+
+
+=head2 Enable C<RenderView> for the Default View
+
+In keeping with Catalyst's goal of providing an extremely flexible
+development platform, a single Catalyst application can simultaneously
+use multiple view rendering technologies. While it's nice to know that
+you are using a deveopment framework with this sort of adaptability, it
+also makes sense that we want to define a default view mechanism for our
+application. Depending on the age of the code, you will likely run into
+one of three different solutions to this issue:
+
+=over 4
+
+=item *
+
+Private C<end> Action in Application Class
+
+Older Catalyst-related documents often suggest that you add a "private
+end action" to your application class (C<MyApp.pm>) or Root.pm
+(C<MyApp/Controller/Root.pm>). These examples should be easily
+converted to L<Catalyst|Catalyst::Action::RenderView> using the example
+code shown below.
+
+=item *
+
+L<Catalyst::Plugin::DefaultEnd|Catalyst::Plugin::DefaultEnd>
+
+C<DefaultEnd> automatically provides a Catalyst "end action" that
+invokes your view at the end of each request. Also allows you to add
+"dump_info=1" (precede with "?" or "&" depending on where it is in the
+URL) to I<force> the debug screen at the end of the Catalyst request
+processing cycle. Although it was easier to implement than the earlier
+C<end> action approach, it was also less extensible than the newer
+L<Catalyst::Action::RenderView|Catalyst::Action::RenderView>.
+
+=item *
+
+L<Catalyst::Action::RenderView|Catalyst::Action::RenderView>
+
+The current recommended approach to handling your view logic relies on
+L<Catalyst::Action::RenderView|Catalyst::Action::RenderView>. Although
+similar to the "private end action" approach, it utilizes Catalyst's
+"ActionClass" mechanism to provide easy extensibility. As with
+C<DefaultEnd>, it allows you to add "dump_info=1" (precede with "?" or
+"&" depending on where it is in the URL) to I<force> the debug screen at
+the end of the Catalyst request processing cycle.
+
+=back
+
+To enable C<RenderView>, edit C<lib/MyApp/Controller/Root.pm> and insert
+the following method:
+
+ =head 2 end
+
+ Forward to a default view.
+
+ =cut
+
+ sub end :ActionClass('RenderView') {
+ my ($self, $c) = @_;
+ $c->forward('MyApp::View::TT') unless $c->res->body;
+ }
+
+
=head2 Globally Customize Every View
When using TTSite, files in the subdirectories of C<root/lib> can be
B<Note:> The Catalyst stash only lasts for a single HTTP request. If
you need to retain information across requests you can use
-L<Catalyst::Plugin::Session> (we will use
-Catalyst sessions in the Authentication part).
+L<Catalyst::Plugin::Session|Catalyst::Plugin::Session> (we will use
+Catalyst sessions in the Authentication part of the tutorial).
=head2 Create a TT Template Page
<td>[% book.title %]</td>
<td>[% book.rating %]</td>
<td>
- [% # Print author count in parens. 'book.authors' uses the 'many_to_many' -%]
- [% # relationship to retrieve all of the authors of a book. 'size' is a -%]
- [% # TT VMethod to get the number of elements in a list. -%]
- ([% book.authors.size %])
- [% # Use an alternate form of a FOREACH loop to display authors. -%]
- [% # _ below is the TT string concatenation operator. -%]
- [% author.last_name _' ' FOREACH author = book.authors %]
- [% # Note: if many_to_many relationship not used in Authors.pm, you could -%]
- [% # have used the following to 'walk' through the 'join table objects' -%]
- [% # bk_author.author.last_name _' ' FOREACH bk_author = book.book_authors %]
+ [% # First initialize a TT variable to hold a list. Then use a TT FOREACH -%]
+ [% # loop in 'side effect notation' to load just the last names of the -%]
+ [% # authors into the list. Note that we make a bogus assignment to the -%]
+ [% # 'unused' vbl to avoid printing the size of the list after each push. -%]
+ [% tt_authors = [ ];
+ unused = tt_authors.push(author.last_name) FOREACH author = book.authors %]
+ [% # Now use a TT 'virtual method' to display the author count in parens -%]
+ ([% tt_authors.size %])
+ [% # Use another vmethod to join & print the names with comma separators -%]
+ [% tt_authors.join(', ') %]
</td>
</tr>
[% END -%]
TT's META feature to provide a title to C<root/lib/site/header>.
Meanwhile, the outer C<FOREACH> loop iterates through each C<book> model
object and prints the C<title> and C<rating> fields. An inner
-C<FOREACH> loop prints the last name of each author in a single table
-cell (a simple space is used between the names; in reality you would
-probably want to modify the code to use a comma as a separator).
+C<FOREACH> loop prints the last name of each author in a comma-separated
+list within a single table cell.
If you are new to TT, the C<[%> and C<%]> tags are used to delimit TT
code. TT supports a wide variety of directives for "calling" other
$ export DBIX_CLASS_STORAGE_DBI_DEBUG=1
+This assumes you are using BASH as your shell -- adjust accordingly if
+you are using a different shell (for example, under tcsh, use
+C<setenv DBIX_CLASS_STORAGE_DBI_DEBUG 1>).
+
B<NOTE>: You can also set this in your code using
C<$class-E<gt>storage-E<gt>debug(1);>. See
L<DBIx::Class::Manual::Troubleshooting> for details (including options
[Tue May 16 12:51:33 2006] [catalyst] [debug] Debug messages enabled
[Tue May 16 12:51:33 2006] [catalyst] [debug] Loaded plugins:
.------------------------------------------------------------------------------.
- | Catalyst::Plugin::ConfigLoader 0.07 |
+ | Catalyst::Plugin::ConfigLoader 0.09 |
| Catalyst::Plugin::Static::Simple 0.14 |
| Catalyst::Plugin::StackTrace 0.04 |
| Catalyst::Plugin::DefaultEnd 0.06 |
Kennedy Clark, C<hkclark@gmail.com>
-Please report any errors, issues or suggestions to the author.
+Please report any errors, issues or suggestions to the author. The
+most recent version of the Catlayst Tutorial can be found at
+L<http://dev.catalyst.perl.org/repos/Catalyst/trunk/Catalyst-Runtime/lib/Catalyst/Manual/Tutorial/>.
Copyright 2006, Kennedy Clark, under Creative Commons License
(L<http://creativecommons.org/licenses/by-nc-sa/2.5/>).
-Version: .94
-
projects / catagits/Catalyst-Runtime.git / blobdiff