Jose original code from http://josediazgonzalez.com/2013/12/12/abusing-exceptions-to-provide-model-layer-redirection/

AppErrorHandler.php

<?php
App::uses('AppException', 'Lib');
App::uses('ErrorHandler', 'Error');

class AppErrorHandler extends ErrorHandler {

  public static function handleException(Exception $exception) {
    if ($exception instanceof AppException) {
      $element = 'default';
      $message = $exception->getMessage();
      $params = array('class' => 'error');
      CakeSession::write('Message.flash', compact('message', 'element', 'params'));
      if ($exception->hasRoute()) {
        $controller = $this->_getController();
        return $controller->redirect($exception->getRoute());
      }
    }

    return parent::handleException($exception);
  }

/**
 * Get the controller instance to handle the exception.
 * Override this method in subclasses to customize the controller used.
 * This method returns the built in `CakeErrorController` normally, or if an error is repeated
 * a bare controller will be used.
 *
 * @param Exception $exception The exception to get a controller for.
 * @return Controller
 */
  protected function _getController($exception) {
    App::uses('CakeErrorController', 'Controller');
    if (!$request = Router::getRequest(true)) {
      $request = new CakeRequest();
    }
    $response = new CakeResponse(array('charset' => Configure::read('App.encoding')));
    try {
      if (class_exists('AppController')) {
        $controller = new CakeErrorController($request, $response);
      }
    } catch (Exception $e) {
    }
    if (empty($controller)) {
      $controller = new Controller($request, $response);
      $controller->viewPath = 'Errors';
    }
    return $controller;
  }

}
?>

FluentAppException.php

<?php
//  app /Lib/Exception/AppException.php
class AppException extends CakeException {
  public function <strong>construct($message, $code = 0) {
    parent::</strong>construct($message, $code);
    return $this;
  }<p></p>

public function setRoute($route = null) {
    $this->_attributes['route'] = $route;
    return $this;
  }
}
?>

NotFluentAppException.php

<?php
//  app /Lib/Exception/AppException.php
class AppException extends CakeException {
  public function setRoute($route = null) {
    $this->_attributes['route'] = $route;
  }

  public function getRoute() {
    return $this->_attributes['route'];
  }

  public function hasRoute() {
    return isset($this->_attributes['route']);
  }
}
?>