In a previous advent story we reviewed a recipe for adding a redispatch method to the global Catalyst object. This allows one to replace the current request with a new request to a different public path (URL). Presented is a different approach to the same problem, but instead of hacking Catalyst internals it creates a new request and dispatches over PSGI. This leads to a higher level of isolation as well as the ability to construct a full HTTP::Request and customize it as need (for example make a POST request, or sets the query parameters.

Here's the method on your application class:

    use warnings;
    use strict;

    package MyApp;

    use Catalyst;
    use HTTP::Message::PSGI ();

    sub redispatch_to {
      my $c = shift;
      my $env = HTTP::Message::PSGI::req_to_psgi(shift);
      our $app ||= $c->psgi_app;

      $c->res->from_psgi_response( $app->($env) );
    }

    MyApp->setup;

This method expects an HTTP::Request as its first argument. We then convert that request to a PSGI style $env hash and invoke it on the application coderef. The response is sent directly to the initiating response.

This would work fine with streaming and delayed style response, FWIW. Here's an example controller using it:

    use warnings;
    use strict;

    package MyApp::Controller::Example;

    use base 'Catalyst::Controller';
    use HTTP::Request::Common;

    sub base :Path('') {
      my ($self, $c) = @_;
      $c->redispatch_to(GET $c->uri_for($self->action_for('target')));
    }

    sub target :Path('target') {
      my ($self, $c) = @_;
      $c->response->content_type('text/plain');
      $c->response->body("This is the target action");
    }

    __PACKAGE__->meta->make_immutable;

And a test case that shows how it works:

    use Test::Most;
    use Catalyst::Test 'MyApp';

    my $res = request "/example";
    is $res->code, 200, 'OK';
    is $res->content, 'This is the target action', 'correct body';

    done_testing;

You might note this would allow one to redispatch to essentially ANY public URL include ones not part of your controlled website. This may be construed as a bug or as a feature.

Same as in the last advent article :)

John Napiorkowski