How to stop continuing in beforefilter without continuing to the main controller?

Question

I'm working with APIs that renders json format in Cakephp. In the AppController.php I have:

public function beforeFilter() {
   $this->RequestHandler->renderAs($this, 'json');

   if($this->checkValid()) {
     $this->displayError();
   }
}
public function displayError() {
  $this->set([
     'result'     => "error",
     '_serialize' => 'result',
  ]);
  $this->response->send();
  $this->_stop();
}

But it doesn't display anything. Though, if it is run normally without stopping and displaying with:

$this->set([
 'result'     => "error",
 '_serialize' => 'result',
]);

is displaying good.

Answer 1

I would look at using Exceptions with a custom json exceptionRenderer.

if($this->checkValid()) {
  throw new BadRequestException('invalid request');
}

add a custom exception handler by including this in your app/Config/bootstrap.php:

/**
 * Custom Exception Handler
 */
App::uses('AppExceptionHandler', 'Lib');

 Configure::write('Exception.handler', 'AppExceptionHandler::handleException');

then create a new custom exception handler in your app/Lib folder named AppExceptionHandler.php

this file can look something like this:

<?php

App::uses('CakeResponse', 'Network');
App::uses('Controller', 'Controller');

class AppExceptionHandler
{

    /*
     * @return json A json string of the error.
     */
    public static function handleException($exception)
    {
        $response = new CakeResponse();
        $response->statusCode($exception->getCode());
        $response->type('json');
        $response->send();
        echo json_encode(array(
            'status' => 'error',
            'code' => $exception->getCode(),
            'data' => array(
                'message' => $exception->getMessage()
            )
        ));
    }
}