Catalyst

From Leaky
Revision as of 21:49, 16 August 2016 by Leaky (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

Creating a model

This generates an interface for Catalyst to a 'MyApp::Item' object and passes all methods through to the object. The example merely passes a 'datadir' attribute on the object that contains the full path to the "data" directory within the application root.

single instance per application

This can be useful if you need a counter that persists between requests for example

package MyApp::Model::Item;

use strict;
use warnings;
use base 'Catalyst::Model';
use MyApp::Item;
use Moose;

our $AUTOLOAD;

has 'Instance' => (
  is => 'rw',
  isa => 'MyApp::Item',
);

__PACKAGE__->config( class => 'MyApp::Item' );

sub COMPONENT {
  my ($self, $app) = @_;
  return MyApp::Item->new( datadir => $app->path_to("data") );
} 

sub AUTOLOAD {
  my $self = shift;
  my $name = $AUTOLOAD;
  $name =~ s/.*://;
  $self->Instance->$name(@_);
}

1;

one instance per request

If you need one instance of $c->model('Item') per request, remove the COMPONENT method and add:

with 'Catalyst::Component::InstancePerContext';

sub build_per_context_instance {
  my ($self, $c) = @_;
  return MyApp::Item->new( datadir => $c->path_to("data") );
}

multiple instance per request

If you need a different instance of $c->model('Item') every time this is called (eg several items in a single request), start with the original example, remove the COMPONENT method and existing use base line and add:

use base 'Catalyst::Model::Factory';

sub ACCEPT_CONTEXT {
  my ($self, $c, @args) = @_;
  return MyApp::Item->new( datadir => $c->path_to("data") );
}


Rewriting all urls from uri_for()

Useful for when there's a proxy in front and it's rewriting things, or when SSL should be enabled and isn't.

Install Catalyst::TraitFor::Request::ProxyBase and add these two bits either side of the line: extends 'Catalyst';

use CatalystX::RoleApplicator;
...
__PACKAGE__->apply_request_class_roles(qw/
    Catalyst::TraitFor::Request::ProxyBase
/);

In Apache config, add into the same sections as your ProxyPass lines:

<Location /preview>
RequestHeader set X-Request-Base http://www.example.com/preview
</Location>