=head1 Basics
These recipes cover some basic stuff that is worth knowing for
-catalyst developers.
+Catalyst developers.
=head2 Delivering a Custom Error Page
if ( scalar @{ $c->error } ) {
$c->stash->{errors} = $c->error;
+ for my $error ( @{ $c->error } ) {
+ $c->log->error($error);
+ }
$c->stash->{template} = 'errors.tt';
$c->forward('MyApp::View::TT');
- $c->error(0);
+ $c->clear_errors;
}
return 1 if $c->response->status =~ /^3\d\d$/;
package MyApp::Controller::Foo;
use Moose;
use namespace::autoclean;
- BEGIN { extends 'Catalyst::Controller';
+ BEGIN { extends 'Catalyst::Controller' };
## Write data into the session
sub add_item : Local {
my ( $self, $c ) = @_;
- my $item_id = $c->req->param("item");
+ my $item_id = $c->req->params->{item};
push @{ $c->session->{items} }, $item_id;
=head1 Skipping your VCS's directories
-Catalyst uses Module::Pluggable to load Models, Views and Controllers.
+Catalyst uses Module::Pluggable to load Models, Views, and Controllers.
Module::Pluggable will scan through all directories and load modules
it finds. Sometimes you might want to skip some of these directories,
for example when your version control system makes a subdirectory with
source control systems. Here is the configuration you need to add
their directories to the list to skip.
-You can make catalyst skip these directories using the Catalyst config:
+You can make Catalyst skip these directories using the Catalyst config:
# Configure the application
__PACKAGE__->config(
=head1 Users and Access Control
-Most multiuser, and some single user web applications require that
+Most multiuser, and some single-user web applications require that
users identify themselves, and the application is often required to
define those roles. The recipes below describe some ways of doing
this.
This is extensively covered in other documentation; see in particular
L<Catalyst::Plugin::Authentication> and the Authentication chapter
-of the Tutorial at L<Catalyst::Manual::Tutorial::Authorization>.
+of the Tutorial at L<Catalyst::Manual::Tutorial::06_Authorization>.
=head2 Pass-through login (and other actions)
=item Authorization
Making sure the user only accesses functions you want them to
-access. This is done by checking the verified users data against your
+access. This is done by checking the verified user's data against your
internal list of groups, or allowed persons for the current page.
=back
A Storage backend contains the actual data representing the users. It
is queried by the credential verifiers. Updating the store is not done
-within this system, you will need to do it yourself.
+within this system; you will need to do it yourself.
Examples:
- DBIC - Storage using a database.
+ DBIC - Storage using a database via DBIx::Class.
Minimal - Storage using a simple hash (for testing).
=head3 User objects
A User object is created by either the storage backend or the
-credential verifier, and filled with the retrieved user information.
+credential verifier, and is filled with the retrieved user information.
Examples:
=head3 ACL authorization
ACL stands for Access Control List. The ACL plugin allows you to
-regulate access on a path by path basis, by listing which users, or
+regulate access on a path-by-path basis, by listing which users, or
roles, have access to which paths.
=head3 Roles authorization
=head3 Checking roles
-Role checking is done by using the C<< $c->check_user_roles >> method,
-this will check using the currently logged in user (via C<< $c->user
+Role checking is done by using the C<< $c->check_user_roles >> method.
+This will check using the currently logged-in user (via C<< $c->user
>>). You pass it the name of a role to check, and it returns true if
the user is a member.
},
},
},
- },
+ },
);
package MyApp::Controller::Root;
use Moose;
use namespace::autoclean;
-
+
BEGIN { extends 'Catalyst::Controller' }
-
+
__PACKAGE__->config(namespace => '');
-
+
sub login : Local {
my ($self, $c) = @_;
- if ( my $user = $c->req->param("user")
- and my $password = $c->req->param("password") )
+ if ( my $user = $c->req->params->{user}
+ and my $password = $c->req->param->{password} )
{
if ( $c->authenticate( username => $user, password => $password ) ) {
$c->res->body( "hello " . $c->user->name );
=head3 Using authentication in a testing environment
-Ideally, to write tests for authentication/authorization code one
-would first set up a test database with known data, then use
+Ideally, to write tests for authentication/authorization code one would
+first set up a test database with known data, then use
L<Test::WWW::Mechanize::Catalyst> to simulate a user logging
-in. Unfortunately the former can be rather awkward, which is why it's
-a good thing that the authentication framework is so flexible.
+in. Unfortunately this can be rather awkward, which is why it's a good
+thing that the authentication framework is so flexible.
Instead of using a test database, one can simply change the
authentication store to something a bit easier to deal with in a
modifying one's database, which can be problematic if one forgets to
use the testing instead of production database.
-Alternatively, if you want to authenticate real users, but not have to worry about
-their passwords, you can use L<Catalyst::Authentication::Credential::Testing>
-to force all users to authenticate with a global password.
+Alternatively, if you want to authenticate real users, but not have to
+worry about their passwords, you can use
+L<Catalyst::Authentication::Credential::Testing> to force all users to
+authenticate with a global password.
=head3 More information
=head3 Introduction
Authorization is the step that comes after
-authentication. Authentication establishes that the user agent is
-really representing the user we think it's representing, and then
-authorization determines what this user is allowed to do.
+authentication. Authentication establishes that the user agent is really
+representing the user we think it's representing, and then authorization
+determines what this user is allowed to do.
=head3 Role Based Access Control
sub feed_moose : Local {
my ( $self, $c ) = @_;
- $c->model( "Moose" )->eat( $c->req->param("food") );
+ $c->model( "Moose" )->eat( $c->req->params->{food} );
}
With this action, anyone can just come into the moose cage and feed
the moose, which is a very dangerous thing. We need to restrict this
action, so that only a qualified moose feeder can perform that action.
-The Authorization::Roles plugin let's us perform role based access
+The Authorization::Roles plugin lets us perform role based access
control checks. Let's load it:
use parent qw/Catalyst/;
my ( $self, $c ) = @_;
if ( $c->check_roles( "moose_feeder" ) ) {
- $c->model( "Moose" )->eat( $c->req->param("food") );
+ $c->model( "Moose" )->eat( $c->req->params->{food} );
} else {
$c->stash->{error} = "unauthorized";
}
Checking for roles all the time can be tedious and error prone.
-The Authorization::ACL plugin let's us declare where we'd like checks
+The Authorization::ACL plugin lets us declare where we'd like checks
to be done automatically for us.
For example, we may want to completely block out anyone who isn't a
clean up in your C<end> private action instead.
Also, it's important to note that if you restrict access to "/" then
-C<end>, C<default>, etc will also be restricted.
+C<end>, C<default>, etc. will also be restricted.
MyApp->acl_allow_root_internals;
write a simple component in Catalyst that slurps in an outside Model:
package MyApp::Model::DB;
+
use base qw/Catalyst::Model::DBIC::Schema/;
+
__PACKAGE__->config(
schema_class => 'Some::DBIC::Schema',
connect_info => ['dbi:SQLite:foo.db', '', '', {AutoCommit=>1}];
);
+
1;
and that's it! Now C<Some::DBIC::Schema> is part of your
=head2 Create accessors to preload static data once per server instance
When you have data that you want to load just once from the model at
-server load instead of for each request, use mk_group_accessors to
+startup, instead of for each request, use mk_group_accessors to
create accessors and tie them to resultsets in your package that
-inherits from DBIx::Class::Schema
+inherits from DBIx::Class::Schema:
package My::Schema;
use base qw/DBIx::Class::Schema/;
and now in the controller, you can now access any of these without a
per-request fetch:
- $c->stash->{something} = $c->model('My::Schema')->schema->ACCESSORNAMEn;
+ $c->stash->{something} = $c->model('My::Schema')->schema->ACCESSORNAME;
=head2 XMLRPC
-Unlike SOAP, XMLRPC is a very simple (and imo elegant) web-services
+Unlike SOAP, XMLRPC is a very simple (and elegant) web-services
protocol, exchanging small XML messages like these:
Request:
=head1 Views
Views pertain to the display of your application. As with models,
-catalyst is uncommonly flexible. The recipes below are just a start.
+Catalyst is uncommonly flexible. The recipes below are just a start.
=head2 Catalyst::View::TT
text if you wanted.
Most Catalyst applications use a template system to generate their HTML,
-and though there are several template systems available, Template
-Toolkit is probably the most popular.
+and though there are several template systems available,
+L<Template Toolkit|Template> is probably the most popular.
Once again, the Catalyst developers have done all the hard work, and
made things easy for the rest of us. Catalyst::View::TT provides the
=head3 Using XML::Feed
-A more robust solution is to use XML::Feed, as was done in the Catalyst
+A more robust solution is to use L<XML::Feed>, as was done in the Catalyst
Advent Calendar. Assuming we have a C<view> action that populates
'entries' with some DBIx::Class iterator, the code would look something
like this:
Controllers are the main point of communication between the web server
and your application. Here we explore some aspects of how they work.
-=head2 Extending RenderView (formerly DefaultEnd)
-
-The recommended approach for an C<end> action is to use
-L<Catalyst::Action::RenderView> (taking the place of
-L<Catalyst::Plugin::DefaultEnd>), which does what you usually need.
-However there are times when you need to add a bit to it, but don't want
-to write your own C<end> action.
-
-You can extend it like this:
-
-To add something to an C<end> action that is called before rendering
-(this is likely to be what you want), simply place it in the C<end>
-method:
-
- sub end : ActionClass('RenderView') {
- my ( $self, $c ) = @_;
- # do stuff here; the RenderView action is called afterwards
- }
-
-To add things to an C<end> action that are called I<after> rendering,
-you can set it up like this:
-
- sub render : ActionClass('RenderView') { }
-
- sub end : Private {
- my ( $self, $c ) = @_;
- $c->forward('render');
- # do stuff here
- }
-
=head2 Action Types
=head3 Introduction
=head3 Type attributes
Each action is a normal method in your controller, except that it has an
-L<attribute|http://search.cpan.org/~nwclark/perl-5.8.7/lib/attributes.pm>
+L<attribute|attributes>
attached. These can be one of several types.
Assume our Controller module starts with the following package declaration:
You can put root actions in your main MyApp.pm file, but this is deprecated,
please put your actions into your Root controller.
-=head3 More Information
+=head3 Flowchart
-L<http://dev.catalyst.perl.org/wiki/FlowChart>
+A graphical flowchart of how the dispatcher works can be found on the wiki at
+L<http://dev.catalyst.perl.org/attachment/wiki/WikiStart/catalyst-flow.png>.
-=head2 DRY Controllers with Chained actions.
+=head2 DRY Controllers with Chained actions
Imagine that you would like the following paths in your application:
=over
-=item B</cd/<ID>/track/<ID>>
+=item B<< /cd/<ID>/track/<ID> >>
Displays info on a particular track.
In the case of a multi-volume CD, this is the track sequence.
-=item B</cd/<ID>/volume/<ID>/track/<ID>>
+=item B<< /cd/<ID>/volume/<ID>/track/<ID> >>
Displays info on a track on a specific volume.
sub key1 : Chained('/')
+=head2 Extending RenderView (formerly DefaultEnd)
+
+The recommended approach for an C<end> action is to use
+L<Catalyst::Action::RenderView> (taking the place of
+L<Catalyst::Plugin::DefaultEnd>), which does what you usually need.
+However there are times when you need to add a bit to it, but don't want
+to write your own C<end> action.
+
+You can extend it like this:
+
+To add something to an C<end> action that is called before rendering
+(this is likely to be what you want), simply place it in the C<end>
+method:
+
+ sub end : ActionClass('RenderView') {
+ my ( $self, $c ) = @_;
+ # do stuff here; the RenderView action is called afterwards
+ }
+
+To add things to an C<end> action that are called I<after> rendering,
+you can set it up like this:
+
+ sub render : ActionClass('RenderView') { }
+
+ sub end : Private {
+ my ( $self, $c ) = @_;
+ $c->forward('render');
+ # do stuff here
+ }
+
+
+
=head1 Deployment
The recipes below describe aspects of the deployment process,
=head2 mod_perl Deployment
-mod_perl is the best solution for many applications, but we'll list some pros
-and cons so you can decide for yourself. The other production deployment
-option is FastCGI, for which see below.
+mod_perl is not the best solution for many applications, but we'll list some
+pros and cons so you can decide for yourself. The other (recommended)
+deployment option is FastCGI, for which see below.
=head3 Pros
=head4 Speed
-mod_perl is very fast and your app will benefit from being loaded in memory
+mod_perl is fast and your app will be loaded in memory
within each Apache process.
=head4 Shared memory for multiple apps
It is not possible to run two different versions of the same application in
the same Apache instance because the namespaces will collide.
+=head4 Cannot run different versions of libraries.
+
+If you have two differnet applications which run on the same machine,
+which need two different versions of a library then the only way to do
+this is to have per-vhost perl interpreters (with different library paths).
+This is entirely possible, but nullifies all the memory sharing benefits that
+you get from having multiple applications sharing the same interpreter.
+
=head4 Setup
Now that we have that out of the way, let's talk about setting up mod_perl
mod_fastcgi for Apache is a third party module, and can be found at
L<http://www.fastcgi.com/>. It is also packaged in many distributions,
-for example, libapache2-mod-fastcgi in Debian.
+for example, libapache2-mod-fastcgi in Debian. You will also need to install
+the L<FCGI> module from cpan.
+
+Important Note! If you experience difficulty properly rendering pages,
+try disabling Apache's mod_deflate (Deflate Module), e.g. 'a2dismod deflate'.
=head4 2. Configure your application
projects / catagits/Catalyst-Manual.git / blobdiff