Facebook application component for Yii.

Facebook.php

<?php
/**
 * FacebookConnect class file.
 * @author Christoffer Niska <ChristofferNiska@gmail.com>
 * @copyright Copyright &copy; Christoffer Niska 2011-
 * @license http://www.opensource.org/licenses/bsd-license.php New BSD License
 */

/**
 * Facebook connection application component.
 */
require(dirname(__FILE__) . '/../../vendors/facebook/facebook.php'); // Yii::import() will not work in this case
class FacebookConnect extends CApplicationComponent
{
    /**
	 * @property string Facebook application id.
	 */
	public $appId;
	/**
	 * @property string Facebook application secret.
	 */
	public $appSecret;
	/**
	 * @property string the application namespace.
	 */
	public $appNamespace;
	/**
	 * @property boolean whether file uploads are enabled.
	 */
	public $fileUpload;

	protected $_userId;
	protected $_facebook;

	/**
	 * Initializes this component.
	 */
	public function init()
	{
		$config = array(
			'appId' => $this->appId,
			'secret' => $this->appSecret
		);

		if ($this->fileUpload !== null)
			$config['fileUpload'] = $this->fileUpload;

		$this->_facebook = new Facebook($config);
	}

	/**
	 * Logs in the current user using facebook.
	 * @return boolean whether the user was logged in successfully
	 */
	public function login()
	{
		$profile = $this->api('me');
		$user = User::model()->findByAttributes(array('email'=>$profile['email']));

		if (!empty($profile))
		{
			if ($user === null)
			{
				$user = new User();
				$user->name = $profile['username'];
				$user->email = $profile['email'];
				$user->fbuid = $profile['id'];
				$user->status = User::STATUS_ACTIVATED;
				$user->activated = new CDbExpression('NOW()');
			}
			// todo: change this once we have collected the data for the existing users.
			else
			{
				if (empty($user->name))
					$user->name = $profile['username'];
				if (empty($user->email))
					$user->email = $profile['email'];
				if (empty($user->fbuid))
					$user->fbuid = $profile['id'];
				if (empty($user->password))
					$user->setNewPassword(uniqid('', true)); // set random passwords for FB users
				if ((int) $user->status === User::STATUS_UNACTIVATED)
				{
					$user->status = User::STATUS_ACTIVATED;
					$user->activated = new CDbExpression('NOW()');
				}
			}

			$user->save(false);
		}

		if ($user !== null)
		{
			// NOTE: Facebook users are not authenticated using a password
			// so we can simply generate a random one to prevent misuse.
			$identity = new UserIdentity($user->name, $user->password);
			$identity->authenticate(UserIdentity::AUTH_TYPE_FACEBOOK);

			if ((int) $identity->errorCode === UserIdentity::ERROR_NONE)
			{
				$duration = 3600 * 24 * 30; // 30 days
				Yii::app()->user->login($identity, $duration);
				return true;
			}
		}

		return false;
	}

	/**
	 * Registers an Open Graph action with Facebook.
	 * @param string $action the action to register.
	 * @param array $params the query parameters.
	 */
	public function registerAction($action, $params=array())
	{
		if (!isset($params['access_token']))
			$params['access_token'] = $this->facebook->getAccessToken();

		$this->api('me/'.$this->appNamespace.':'.$action, $params);
	}
	
	/**
	 * Returns the model for the currently logged in Facebook user.
	 * @return User the user model.
	 */
	public function loadUser()
	{
		$fbuid = $this->getUserId();
		return $fbuid > 0 ? User::model()->findByAttributes(array('fbuid'=>$fbuid)) : null;
	}

	/**
	 * @return integer the Facebook user id.
	 */
	public function getUserId()
	{
		if ($this->_userId !== null)
			return $this->_userId;
		else
		{
			$userId = 0;

			try
			{
				$userId = $this->_facebook->getUser();
			}
			catch (FacebookApiException $e)
			{
			}

			return $this->_userId = $userId;
		}
	}

	/**
	 * Returns the locale based on the application language.
	 * @return string the locale.
	 */
	public function getLocale()
	{
		$language = Yii::app()->language;

		if ($language !== null)
		{
			$pieces = explode('_', $language);
			if (count($pieces) === 2)
				return $pieces[0].'_'.strtoupper($pieces[1]);
		}

		return 'en_US';
	}

	/**
	 * Calls the Facebook API.
	 * @param string $query the query to send.
	 * @param array $params the query paramters.
	 * @return array the response.
	 */
	public function api($query, $params=array())
	{
		$data = array();

		if (!empty($params))
			$query .= '?'.http_build_query($params);

		try
		{
			$data = $this->_facebook->api('/'.$query);
		}
		catch (FacebookApiException $e)
		{
		}

		return $data;
	}

	/**
	 * @return Facebook the Facebook application instance.
	 */
	public function getFacebook()
	{
		return $this->_facebook;
	}
}