fb_oauth.pl

## fb_oauth.pl
#!/usr/bin/env perl
use Mojolicious::Lite;
use Net::Facebook::Oauth2;

my $config = {
  facebook => {
      app_id => '',
      secret => '',
      redirect_url => 'http://mojo.dev:3000/redirect_from_fb',
    },
};

plugin 'o_auth2', {
  facebook => {
    key    => $config->{facebook}->{app_id},
    secret => $config->{facebook}->{secret},
}};

get '/' => sub {
  my $self = shift;

  $self->redirect_to('authenticate') unless $self->session->{user}->{fb_username};
  return $self->render('index_authenticated');

} => 'index';

get authenticate => sub {
  my $self = shift;

  my $url = $self->get_authorize_url(
    'facebook',
    scope => 'offline_access publish_stream user_likes email',
    redirect_uri => $config->{facebook}->{redirect_url},
  );

  $self->redirect_to( $url->to_abs->to_string );
} => 'authenticate';

get redirect_from_fb => sub {
  my $self = shift;
  my $token = $self->param('code');

  my $fb = Net::Facebook::Oauth2->new(
    application_id     => $config->{facebook}->{app_id},
    application_secret => $config->{facebook}->{secret},
    access_token       => $token,
    callback           => $config->{facebook}->{redirect_url}
  );

	my $access_token = $fb->get_access_token(code => $token);

	$fb = Net::Facebook::Oauth2->new(
		access_token => $access_token
  );

	my $info = $fb->get(
		'https://graph.facebook.com/me'
  );

  print $info->as_json;

  $self->session->{user} = {
	    fb_username   => $info->as_hash->{name},
  };

  $self->redirect_to('index');
} => 'redirect_from_fb';

app->start;
__DATA__

@@ index_unauthenticated.html.ep
% layout 'default';

<%= link_to 'Click here to authenticate with FB' => 'authenticate'; %>

@@ index_authenticated.html.ep
% layout 'default';

Hello <%= session->{user}->{fb_username} %>

<%= link_to 'Click here to authenticate with FB' => 'authenticate'; %>

@@ layouts/default.html.ep
<!DOCTYPE html>
<html>
  <body><%= content %></body>
</html>