base\Controller beforeAction()

This method is invoked right before an action is executed.

The method will trigger the EVENT_BEFORE_ACTION event. The return value of the method will determine whether the action should continue to run.

In case the action should not run, the request should be handled inside of the beforeAction code by either providing the necessary output or redirecting the request. Otherwise the response will be empty.

If you override this method, your code should look like the following:

public function beforeAction($action)
{
    // your custom code here, if you want the code to run before action filters,
    // which are triggered on the [[EVENT_BEFORE_ACTION]] event, e.g. PageCache or AccessControl

    if (!parent::beforeAction($action)) {
        return false;
    }

    // other custom code here

    return true; // or false to not run the action
}