Facebook Plugin for CakePHP

Step 1. Download, unzip and rename the folder to Facebook and move it to the Plugin's folder of your CakePHP project.

Step 2. In Config/bootstrap.php, enable the plugin and it's bootstrap, by adding a line like this:

CakePlugin::loadAll(
	array('Facebook' => array('bootstrap' => true))
);

Step 3. You must have a table for Users and a model, with at least one field for "uid". If you don't have one, something like this is fine:

Table:

CREATE TABLE users (
    id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(50),
    uid VARCHAR(50)
);

Model:

<?php
App::uses('AppModel', 'Model');

class User extends AppModel {
}
?>

Step 4. Enable Auth component in AppController.php and link it to Facebook Authentication. For example:

public $components = array(
	'Session',
	'Auth' => array(
		'loginAction' => array(
			'plugin' => 'facebook',
			'controller' => 'users',
			'action' => 'login'
		),
		'loginRedirect' => '/',
		'logoutRedirect' => '/',
		'authenticate' => array(
			'all' => array('userModel' => 'User'),
			'Facebook.Oauth'
		)
	)
);

Step 5. In Config/database.php, enter the AppKey and AppSecret from your Facebook App, your app complete url, and your login action:

public $facebook = array(
	'datasource' => 'Facebook.FQL',
	'app_url' => 'http://www.yourdomain.com/path/to/cake', // or just http://www.yourdomain.com if it's on the root
	'app_id' => '35868871xxxxxx',
	'app_secret' => '6059c46e362346xxxxxxxxxxxx'
);

Example 1. How to natively login to CakePHP Auth using Facebook:

// In the Controller include FacebookHelper
public $helpers = array('Facebook.Facebook');

// In the View (probably in Users/login.ctp) print the login button
echo $this->Facebook->loginButton();

// In the View print the logout button
echo $this->Html->link('Logout', array('plugin' => 'facebook', 'controller' => 'users', 'action' => 'logout'));

By default, the above example will print a raw link with the label "Login". If you want to customize it, you can easily do it by passing some params:

// The text of the link
$label = "Facebook Login!";

// The same options as HtmlHelper::link()
$options = array(
	'class' => 'btn_login',
	'id' => 'facebook'
);

// The permissions we need from the user
$permissions = array('email','user_photos');

echo $this->loginButton($label, $options, $permissions);

Example 2. Get all the albums from the user:

// In the Controller include the FacebookAlbum model
public $uses = array('Facebook.FacebookAlbum');
	
// In the same Controller, in an action
$albums = $this->FacebookAlbum->find('all', array('fields' => array('FacebookAlbum.name'), 'conditions' => array('FacebookAlbum.owner' => $this->Auth->User('uid'))));
$this->set(compact('albums'));

// In the view from that action
foreach ($albums as $album) {
	echo $album['FacebookAlbum']['name']." - ";
}