Flow Control

Occasionally a controller action will want to divert, re-route, or automatically configure the view layer based on an incoming request. There are various controller methods to help facilitate request flow handling.

Redirection

The most basic type of flow control at the controller level is redirection. It’s common to redirect a user to a new URL once an action has been performed. This type of control is done through the controller’s redirect() method. Here’s an example of a controller action that redirects the request:

public function add() {
    // Validate and save user data POSTed to the
    // controller action found in $this->request->data...
    return $this->redirect(["Users::view", "id" => $user->id, "?" => "welcome"]);
}

The URL specified can be relative to the application or point to an outside resource. The redirect() function also features a second $options parameter that also allows you to set HTTP status headers, and make decisions about whether or not to exit() after a redirect. Be sure to check the API for lithium\action\Controller::redirect() for more details.

Other Types of Flow Control

li3 provides other options for request flow control, such as exception and error handling and type rendering & detection, both of which are explained in more detail in their respective manual pages.