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+---
+date: 2009-05-18T00:00:00Z
+summary: In which we had one more article on how to write a feed aggregator.
+title: A simple feed aggregator with modern Perl - part 4.1
+---
+
+You can thanks [bobtfish](http://github.com/bobtfish) for being such a pedantic guy, 'cause now you will have a better chained examples. He forked my repository from GitHub and fix some code that I'll explain here.
+
+### lib/MyFeedReader.pm
+
+```perl
+ package MyFeedReader;
++use Moose;
++use namespace::autoclean;
+
+-use strict;
+-use warnings;
+-
+-use Catalyst::Runtime '5.70';
++use Catalyst::Runtime '5.80';
+
+-use parent qw/Catalyst/;
++extends 'Catalyst';
+```
+
+You can see that he use [Moose](http://search.cpan.org/perldoc?Moose), so we can remove
+
+```perl
+use strict;
+use warnings;
+```
+
+and have a more elegant way to inherit from [Catalyst](http://search.cpan.org/perldoc?Catalyst) with
+
+```perl
+extends 'Catalyst';
+```
+
+instead of
+
+```perl
+use parent qw/Catalyst/;
+```
+
+He also have updated the **Catalyst::Runtime** version, and added **namespace::autoclean**. The purpose of this module is to keep imported methods out of you namespace. Take a look at the "documentation":http://search.cpan.org/perldoc?namespace::autoclean, it's easy to understand how and why it's usefull.
+
+### lib/MyFeedReader/Controller/Root.pm
+
+```perl
+-use strict;
+-use warnings;
+-use parent 'Catalyst::Controller';
++use Moose;
++use namespace::autoclean;
++BEGIN { extends 'Catalyst::Controller' }
+
+-sub index :Path :Args(0) {
++sub root : Chained('/') PathPart() CaptureArgs(0) {}
++
++sub index : Chained('root') PathPart('') Args(0) {
+        my ( $self, $c ) = @_;
+
+        # Hello World
+        $c->response->body( $c->welcome_message );
+    }
+
+-sub default :Path {
++sub default : Private {
+        my ( $self, $c ) = @_;
+        $c->response->body( 'Page not found' );
+        $c->response->status(404);
+```
+
+A new method, `root`, that will be the root path for our application. All our methods will be chained from this action. If start you catalyst server and go to **http://localhost:3000/** you will be served with the Catalyst's welcome message as before.
+
+### lib/MyFeedReader/Controller/Entry.pm
+
+```perl
+-use warnings;
++use Moose;
+ use MyAggregator::Entry;
+-use parent 'Catalyst::Controller';
+-
+-__PACKAGE__->config->{namespace} = 'entry';
++use namespace::autoclean;
++BEGIN { extends 'Catalyst::Controller'; }
+
+-sub view : Chained('/') : PathPart('entry') : Args(1) {
++sub view : Chained('/root') : PathPart('entry') : Args(1) {
+     my ( $self, $c, $id ) = @_;
+
+     $c->stash->{entry} = $c->model('KiokuDB')->lookup($id);
+ }
+
+-1;
+-
++__PACKAGE__->meta->make_immutable;
+```
+
+We extends the **Catalyst::Controller** in a Moose way, and the `make_immutable` instruction is a Moose recommanded best practice (you can alsa add `no Moose` after the make_immutable).
+
+### lib/MyFeedreader/Controller/Feed.pm
+
+```perl
++use Moose;
++use namespace::autoclean;
++BEGIN { extends 'Catalyst::Controller' }
+
+-use strict;
+-use warnings;
+-use parent 'Catalyst::Controller';
++sub feed : Chained('/root') PathPart('feed') CaptureArgs(0) {}
+
+-__PACKAGE__->config->{namespace} = 'feed';
+-
+-sub index : Path : Args(0) {
++sub index : Chained('feed') PathPart('') Args(0) {
+     my ( $self, $c ) = @_;
+
+     $c->stash->{feeds}
+         = [ $c->model('MyModel')->resultset('Feed')->search() ];
+ }
+
+-sub view : Chained('/') : PathPart('feed/view') : Args(1) {
++sub view : Chained('feed') : PathPart('view') : Args(1) {
+     my ( $self, $c, $id ) = @_;
+
+     $c->stash->{feed}
+         = $c->model('MyModel')->resultset('Feed')->find($id);
+ }
+
+-1;
++__PACKAGE__->meta->make_immutable;
+```
+
+We got `feed` which is chained to root. `index` is chained to feed, and take no arguments. This method display the list of our feeds. And we got the `view` method, chained to feed too, but with one argument, that display the content of an entry.
+
+If you start the application, you will see the following routes:
+
+
+    .-------------------------------------+--------------------------------------.
+    | Path Spec                           | Private                              |
+    +-------------------------------------+--------------------------------------+
+    | /root/entry/*                       | /root (0)                            |
+    |                                     | => /entry/view                       |
+    | /root/feed                          | /root (0)                            |
+    |                                     | -> /feed/feed (0)                    |
+    |                                     | => /feed/index                       |
+    | /root/feed/view/*                   | /root (0)                            |
+    |                                     | -> /feed/feed (0)                    |
+    |                                     | => /feed/view                        |
+    | /root                               | /root (0)                            |
+    |                                     | => /index                            |
+    '-------------------------------------+--------------------------------------'
+
+I hope you got a better idea about chained action in catalyst now. And again, thanks to bobtfish for the code.