[Catalyst] Facebook canvas application in Catalyst

Gunnar Strand gunnarstrand at yahoo.com
Thu Oct 15 20:22:15 GMT 2009

From: J. Shirley <jshirley at gmail.com>
To: The elegant MVC web framework <catalyst at lists.scsys.co.uk>
Sent: Thu, October 15, 2009 9:44:13 PM
Subject: Re: [Catalyst] Facebook canvas application in Catalyst

On Thu, Oct 15, 2009 at 12:25 PM, Gunnar Strand <gunnarstrand at yahoo.com> wrote:

>>I am trying to write a Facebook canvas application in Catalyst using the WWW::Facebook::API plugin and I am tearing my hair trying to get it to work.
>>I have no problems with access to my canvas application from Facebook, but I am unable to use any of the $c->facebook interface methods to acquire user data, eg. friend list, event information etc.
>>I would be very grateful if anyone could post an example of, for instance, getting the currently logged in user's friends, or event information or any information at all via the $c->facebook interface. All I get is error when using the methods in the interface and the problem is definitely on this side of the keyboard.

Hi Gunnar,

I've been meaning to write a blog entry on this, since there are some points to be aware of.  I've built my own model that creates a per-context instance and works quite well.  It isn't on CPAN (yet) but I should probably release it.

I would advise against using the Plugin, as it's not modifying the application behavior or dispatching so having it as a plugin is a bad fit.

I posted my code in a gist: http://gist.github.com/211218 

Keep in mind that you can't do differentiation on request type like GET/POST through the canvas.  Make sure that you have the application added to your profile (check the app added, there is a chain mid-point to do this in the gist).

Hope this helps,


Hi J,

Thank you for the quick reply! I have looked through the code and I cannot understand what the problem is for me. I have tried making this as simple as possible to eliminate any potential errors and still don't get it to work. I removed the plugin and I now have this code in the top index, some shamelessly copied from your page :-):

sub index : Path : Args(0) {
    my ( $self, $c ) = @_;

    my $client = new WWW::Facebook::API(
        app_id  => '174563349128',
        api_key => 'ce82845d86baa6d633efa5f00d83575a',
        desktop => 0,
        secret  => '<secret id>',

    my $params    = $c->req->params;
    my $fb_params = $client->canvas->get_fb_params( $c->req );

    if ( $params->{'auth_token'} ) {
        $client->auth->get_session( $params->{'auth_token'} );

    if ( $fb_params->{session_key} ) {
        $client->session_key( $fb_params->{session_key} );
    use Data::Dumper;

    my $output = Dumper( $client->friends->get );

    $c->response->body( '<pre>' 
            . $output 
            . '</pre>'

And the output is still:

$VAR1 = {
          'error_msg' => 'Incorrect signature',
          'request_args' => [
                                'value' => 'ce82845d86baa6d633efa5f00d83575a',
                                'key' => 'api_key'
                                'value' => 'JSON',
                                'key' => 'format'
                                'value' => 'facebook.friends.get',
                                'key' => 'method'
                                'value' => '2.0POf_Dzs6W1VEJY2ZW1J5A__.86400.1255726800-100000257794276',
                                'key' => 'session_key'
                                'value' => '1.0',
                                'key' => 'v'
                                'value' => 'f5558065b76063dd63a8777eb5da8d7a',
                                'key' => 'sig'
          'error_code' => 104

I've rechecked the api_key and secret, and they are correct. I guess that that the source above really should product useful output?

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