Adding a logout callback to authenticate objects.

Adding tests for the callback.
Adding doc blocks for the new callback.
Fixes #1758

lib/Cake/Controller/Component/Auth/BaseAuthenticate.php

@@ -98,6 +98,18 @@ protected function _findUser($username, $password) {
  */
 	abstract public function authenticate(CakeRequest $request, CakeResponse $response);
 
+/**
+ * Allows you to hook into AuthComponent::logout(), 
+ * and implement specialized logout behaviour.
+ * 
+ * All attached authentication objects will have this method 
+ * called when a user logs out.
+ *
+ * @param array $user The user about to be logged out.
+ * @return void
+ */
+	public function logout($user) { }
+
 /**
  * Get a user based on information in the request.  Primarily used by stateless authentication
  * systems like basic and digest auth.
@@ -108,4 +120,4 @@ abstract public function authenticate(CakeRequest $request, CakeResponse $respon
 	public function getUser($request) {
 		return false;
 	}
-}
+}

lib/Cake/Controller/Component/AuthComponent.php

@@ -516,6 +516,9 @@ public function login($user = null) {
 
 /**
  * Logs a user out, and returns the login action to redirect to.
+ * Triggers the logout() method of all the authenticate objects, so they can perform
+ * custom logout logic.  AuthComponent will remove the session data, so
+ * there is no need to do that in an authentication object.
  *
  * @param mixed $url Optional URL to redirect the user to after logout
  * @return string AuthComponent::$loginAction
@@ -524,6 +527,13 @@ public function login($user = null) {
  */
 	public function logout() {
 		$this->__setDefaults();
+		if (empty($this->_authenticateObjects)) {
+			$this->constructAuthenticate();
+		}
+		$user = $this->user();
+		foreach ($this->_authenticateObjects as $auth) {
+			$auth->logout($user);
+		}
 		$this->Session->delete(self::$sessionKey);
 		$this->Session->delete('Auth.redirect');
 		return Router::normalize($this->logoutRedirect);

lib/Cake/Test/Case/Controller/Component/AuthComponentTest.php

@@ -1061,6 +1061,17 @@ public function testLogout() {
 		$this->assertNull($this->Auth->Session->read('Auth.redirect'));
 	}
 
+	public function testLogoutTrigger() {
+		$this->getMock('BaseAuthenticate', array('authenticate', 'logout'), array(), 'LogoutTriggerMockAuthenticate', false);
+
+		$this->Auth->authenticate = array('LogoutTriggerMock');
+		$mock = $this->Auth->constructAuthenticate();
+		$mock[0]->expects($this->once())
+			->method('logout');
+
+		$this->Auth->logout();
+	}
+
 /**
  * test mapActions loading and delegating to authorize objects.
  *