package Catalyst::Controller::MessageDriven;
use Moose;
use Data::Serializer;
use namespace::autoclean;
BEGIN { extends 'Catalyst::Controller' }
=head1 NAME
Catalyst::Controller::MessageDriven
=head1 SYNOPSIS
package MyApp::Controller::Queue;
use Moose;
BEGIN { extends 'Catalyst::Controller::MessageDriven' }
sub some_action : Local {
my ($self, $c, $message) = @_;
# Handle message
# Reply with a minimal response message
my $response = { type => 'testaction_response' };
$c->stash->{response} = $response;
}
=head1 DESCRIPTION
A Catalyst controller base class for use with Catalyst::Engine::Stomp,
which handles YAML-serialized messages. A top-level "type" key in the
YAML determines the action dispatched to.
=head1 METHODS
=head2 begin
Deserializes the request into C<< $c->stash->{request} >>
=head2 default
Dispatches to method named by the key C<< $c->stash->{request}->{type} >>
=head2 end
Serializes the response from C<< $c->stash->{response} >>
=cut
__PACKAGE__->config( serializer => 'YAML' );
sub begin : Private {
my ($self, $c) = @_;
# Deserialize the request message
my $message;
my $serializer = $self->config->{serializer};
my $s = Data::Serializer->new( serializer => $serializer );
eval {
my $body = $c->request->body;
open my $IN, "$body" or die "can't open temp file $body";
$message = $s->raw_deserialize(do { local $/; <$IN> });
};
if ($@) {
# can't reply - reply_to is embedded in the message
$c->error("exception in deserialize: $@");
}
else {
$c->stash->{request} = $message;
}
}
sub end : Private {
my ($self, $c) = @_;
# Engine will send our reply based on the value of this header.
$c->response->headers->header( 'X-Reply-Address' => $c->stash->{request}->{reply_to} );
# The wire response
my $output;
# Load a serializer
my $serializer = $self->config->{serializer};
my $s = Data::Serializer->new( serializer => $serializer );
# Custom error handler - steal errors from catalyst and dump them into
# the stash, to get them serialized out as the reply.
if (scalar @{$c->error}) {
my $error = join "\n", @{$c->error};
$c->stash->{response} = { status => 'ERROR', error => $error };
$output = $s->serialize( $c->stash->{response} );
$c->clear_errors;
$c->response->status(400);
}
# Serialize the response
eval {
$output = $s->raw_serialize( $c->stash->{response} );
};
if ($@) {
my $error = "exception in serialize: $@";
$c->stash->{response} = { status => 'ERROR', error => $error };
$output = $s->serialize( $c->stash->{response} );
$c->response->status(400);
}
$c->response->output( $output );
}
sub default : Private {
my ($self, $c) = @_;
# Forward the request to the appropriate action, based on the
# message type.
my $action = $c->stash->{request}->{type};
if (defined $action) {
$c->forward($action, [$c->stash->{request}]);
}
else {
$c->error('no message type specified');
}
}
__PACKAGE__->meta->make_immutable;