Zend Framework 2 : Programmatically handle 404 page

Sometime, in real life project, we need to handle 404 page more than only show the 404 page, but logging, redirecting, forwarding, change template/content, etc. We can handle it by programmatically at Module.php. In Zend Framework 2, there is 4 types of 404 ( page not found ), they are : ERROR_CONTROLLER_CANNOT_DISPATCH, ERROR_CONTROLLER_NOT_FOUND, ERROR_CONTROLLER_INVALID, and ERROR_ROUTER_NO_MATCH.  Let’s investigate one by one.

1. ERROR_CONTROLLER_CANNOT_DISPATCH
It means the controller is matched, but the action that passed to the url can’t be dispatched. We can handle it via onBootstrap like the following :

namespace YourModule;

use Zend\Mvc\MvcEvent;

class Module
{
    public function onBootstrap(MvcEvent $e)
    {
        $eventManager  = $e->getApplication()->getEventManager();
        $sharedManager = $eventManager->getSharedManager();
        //controller can't dispatch request action that passed to the url
        $sharedManager->attach('Zend\Mvc\Controller\AbstractActionController',
                  'dispatch', 
                  array($this, 'handleControllerCannotDispatchRequest' ), 101);
    }

    public function handleControllerCannotDispatchRequest(MvcEvent $e)
    {
        $action = $e->getRouteMatch()->getParam('action');
        $controller = get_class($e->getTarget());
        
        // error-controller-cannot-dispatch
        if (! method_exists($e->getTarget(), $action.'Action')) {
            $logText = 'The requested controller '.
                        $controller.' was unable to dispatch the request : '.$action.'Action';
            //you can do logging, redirect, etc here..
             echo $logText;
        }
    }   

    public function getConfig() { //common code here }
    public function getAutoloaderConfig() { //common code here }
}

2. ERROR_CONTROLLER_NOT_FOUND
It means controller class not found with requested [/:controller] route that defined already at module.config.php
3. ERROR_CONTROLLER_INVALID
It means the controller is not dispatchable, it usually because the controller is not extends Zend\Mvc\Controller\AbstractActionController
4. ERROR_ROUTER_NO_MATCH
It means The requested URL could not be matched by routing, for example, there is no route with prefix /foo that passed at the url.
For point 2, 3, and 4, we can handle by :

namespace YourModule;

use Zend\Mvc\MvcEvent;
use Zend\Mvc\Application;

class Module
{
    public function onBootstrap(MvcEvent $e)
    {
        $eventManager = $e->getApplication()->getEventManager();
        $eventManager->attach('dispatch.error',
             array($this,
             'handleControllerNotFoundAndControllerInvalidAndRouteNotFound'), 100);
    }
     
    public function handleControllerNotFoundAndControllerInvalidAndRouteNotFound(MvcEvent $e)
    {
        $error  = $e->getError();
        if ($error == Application::ERROR_CONTROLLER_NOT_FOUND) {
            //there is no controller named $e->getRouteMatch()->getParam('controller')
            $logText =  'The requested controller '
                        .$e->getRouteMatch()->getParam('controller'). '  could not be mapped to an existing controller class.';
            
            //you can do logging, redirect, etc here..
            echo $logText;
        }
        
        if ($error == Application::ERROR_CONTROLLER_INVALID) {
            //the controller doesn't extends AbstractActionController
            $logText =  'The requested controller '
                        .$e->getRouteMatch()->getParam('controller'). ' is not dispatchable';
            
            //you can do logging, redirect, etc here..
            echo $logText;
        }
        
        if ($error == Application::ERROR_ROUTER_NO_MATCH) {
            // the url doesn't match route, for example, there is no /foo literal of route
            $logText =  'The requested URL could not be matched by routing.';
            //you can do logging, redirect, etc here...
            echo $logText;
        }
    } 
    public function getConfig() { //common code here }
    public function getAutoloaderConfig() { //common code here }
}

Want to handle All ? Let’s do this :

namespace YourModule;
use Zend\Mvc\MvcEvent;
use Zend\Mvc\Application;

class Module
{
    public function onBootstrap(MvcEvent $e)
    {
        $eventManager = $e->getApplication()->getEventManager();
        $sharedManager = $eventManager->getSharedManager();
        //controller can't dispatch request action that passed to the url
        $sharedManager->attach('Zend\Mvc\Controller\AbstractActionController',
               'dispatch',
               array($this, 'handleControllerCannotDispatchRequest' ), 101);
        //controller not found, invalid, or route is not matched anymore
        $eventManager->attach('dispatch.error', 
               array($this,
              'handleControllerNotFoundAndControllerInvalidAndRouteNotFound' ), 100);
    }
    
    public function handleControllerCannotDispatchRequest(MvcEvent $e)
    {
        $action = $e->getRouteMatch()->getParam('action');
        $controller = get_class($e->getTarget());
        
        // error-controller-cannot-dispatch
        if (! method_exists($e->getTarget(), $action.'Action')) {
            $logText = 'The requested controller '.
                        $controller.' was unable to dispatch the request : '.$action.'Action';
            //you can do logging, redirect, etc here..
             echo $logText;
        }
    }
    
    public function handleControllerNotFoundAndControllerInvalidAndRouteNotFound(MvcEvent $e)
    {
        $error  = $e->getError();
        if ($error == Application::ERROR_CONTROLLER_NOT_FOUND) {
            //there is no controller named $e->getRouteMatch()->getParam('controller')
            $logText =  'The requested controller '
                        .$e->getRouteMatch()->getParam('controller'). '  could not be mapped to an existing controller class.';
            
            //you can do logging, redirect, etc here..
            echo $logText;
        }
        
        if ($error == Application::ERROR_CONTROLLER_INVALID) {
            //the controller doesn't extends AbstractActionController
            $logText =  'The requested controller '
                        .$e->getRouteMatch()->getParam('controller'). ' is not dispatchable';
            
            //you can do logging, redirect, etc here..
            echo $logText;
        }
        
        if ($error == Application::ERROR_ROUTER_NO_MATCH) {
            // the url doesn't match route, for example, there is no /foo literal of route
            $logText =  'The requested URL could not be matched by routing.';
            //you can do logging, redirect, etc here...
            echo $logText;
        }
    } 
    
    public function getConfig(){ // common code }
    public function getAutoloaderConfig(){ //common code }
}

Done 😉

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