File Coverage

blib/lib/Dancer/Plugin/Facebook.pm

Criterion	Covered	Total	%
statement	32	80	40.0
branch	5	26	19.2
condition	2	12	16.6
subroutine	8	13	61.5
pod			n/a
total	47	131	35.8

package Dancer::Plugin::Facebook;
{
  $Dancer::Plugin::Facebook::VERSION = '0.991';
}
# ABSTRACT: Manage Facebook interaction within Dancer applications

use Dancer qw{:syntax};
use Dancer::Hook;
use Dancer::Plugin;
use Facebook::Graph;
use Try::Tiny;


my (%config, $fb, $redirect);

sub _get_fb {
    debug "Getting fb object [", $fb // "undef", "]";

    # The first time out, turn our raw, local postback URL into a
    # fully qualified one (see _do_fb_postback for more explanation).
    if ($config{raw_postback}) {
        my $url = delete $config{raw_postback};
        # Place the postback url in $config for object instantiation
        $config{postback} = uri_for ($url);
        debug "Full postback URL is ", $config{postback};
    }

    # We use a before hook to clear a stale FB handle out, and just
    # use ||= to regenerate as necessary here.
    $fb ||= do {
        my %settings = %config;
        if (my $access_token = session->{auth}->{facebook}) {
            $settings{access_token} = $access_token;
        }
        debug "Creating Facebook::Graph object with settings ", \%settings;
        Facebook::Graph->new (%settings);
    };
}

sub _get_fb_redirect_url () {
    $redirect ||= do {
        my $settings = plugin_setting;
        debug "Settings are ", $settings;
        my @permissions = ref $settings->{permissions} eq "ARRAY" ? @{$settings->{permissions}} : ();
        _get_fb->authorize->extend_permissions (@permissions)->uri_as_string;
    };
}

sub _do_fb_redirect () {
    my $url = _get_fb_redirect_url;
    sub {
        debug "Redirecting to $url";
        redirect $url, 303;
    }
}

sub _do_fb_postback ($) {
    my $settings = plugin_setting;
    debug "Settings are ", $settings;

    my ($url) = @_;

    # We can only determine the relative URL right now, but that's
    # enough for initializing the route.  We put the relative URL
    # in $config{raw_postback} so that when fb is called for the
    # first time, which will be within a route handler, we can sub
    # in the full URL, which is what FB actually needs
    die "You must give me the postback URL when calling fb_postback" unless ($url);
    $config{raw_postback} = $url;

    # This hook will get called when we successfully authenticate and have
    # put the token in the session, so the application developer can
    # retrieve it.  It doesn't need to exist if a postback route hasn't been
    # established
    register_hook (['fb_access_token_available']);

    my $success = $settings->{landing}->{success} || "/";
    my $failure = $settings->{landing}->{failure} || "/";

    sub {
        try {
            my $token = _get_fb->request_access_token (params->{code});
            session->{auth}->{facebook} = $token->token;
            execute_hooks 'fb_access_token_available', $token->token;
            # Go back wherever
            redirect $success;
        } catch {
            redirect $failure;
        };
    }
}

register setup_fb => sub (;$) {
    my ($url) = @_;
    debug "Setting up fb access";

    # We need global access to this, grab it here
    my $settings = plugin_setting;
    debug "Settings are ", $settings;

    # Copy our registered application information over
    if (ref $settings->{application} eq "HASH") {
        debug "Setting application information";
        $config{app_id} = $settings->{application}->{app_id} or die "You didn't give me an app_id for Dancer::Plugin::Facebook";
        $config{secret} = $settings->{application}->{secret} or die "You didn't give me a secret for Dancer::Plugin::Facebook";
    }

    # Set a hook to clear out any old object unless existing tokens in
    # the object and session match one another.  In theory, this means
    # that absent an access token, we should never replace it.
    debug "Setting hook to clear facebook context";
    hook before => sub {
        if (defined $fb) {
            debug "Considering clearing facebook context";
            if (defined session->{auth}->{facebook}) {
                if ($fb->has_access_token) {
                    if ($fb->access_token ne session->{auth}->{facebook}) {
                        debug "Current FB access token doesn't match";
                        undef $fb;
                    }
                } else {
                    debug "Current FB doesn't have access token";
                    undef $fb;
                }
            } else {
                if ($fb->has_access_token) {
                    debug "Current login doesn't have access token";
                    undef $fb;
                }
            }
        }
    };

    # If the user wants the automatic URL setup
    if ($url) {
        debug "Creating handler for ", $url;
        get $url => _do_fb_redirect;

        my $postback = "$url/postback";
        debug "Creating handler for ", $postback;
        get $postback => _do_fb_postback $postback;
    }

    debug "Done setting up fb access";
};

register fb => \&_get_fb;
register fb_redirect => \&_do_fb_redirect;
register fb_redirect_url => \&_get_fb_redirect_url;
register fb_postback => \&_do_fb_postback;
register_plugin;


1;

__END__