Zend2 Routing __NAMESPACE__ doesn't work or be ignored

Question

I'm using this config as my application module config in Zend2 which is really normal and every one suggested as a standard routing rule:

'controllers'  => array(
    'invokables' => array(
        'Application\Controller\Index'   => 'Application\Controller\IndexController',
    ),
),
'router'       => array(
    'routes' => array(
        'home' => array(
            'type' => 'Zend\Mvc\Router\Http\Literal',
            'options' => array(
                'route'    => '/',
                'defaults' => array(
                    'controller' => 'Application\Controller\Index',
                    'action'     => 'index',
                ),
            ),
        ),
        'application' => array(
            'type'    => 'Zend\Mvc\Router\Http\Literal',
            'options' => array(
                'route'    => '/application',
                'defaults' => array(
                    '__NAMESPACE__' => 'Application\Controller',
                    'controller'    => 'Index',
                    'action'        => 'index',
                ),
            ),
            'may_terminate' => true,
            'child_routes' => array(
                'default' => array(
                    'type'    => 'Zend\Mvc\Router\Http\Segment',
                    'options' => array(
                        'route'    => '/[:controller[/:action]]',
                        'constraints' => array(
                            'controller' => '[a-zA-Z][a-zA-Z0-9_-]*',
                            'action'     => '[a-zA-Z][a-zA-Z0-9_-]*',
                        ),
                        'defaults' => array(
                        ),
                    ),
                ),
            ),
        ),
    ),
),

the routing for home works fine. but for http://localhost/application I get:

Index(resolves to invalid controller class or alias: Index)

and for http://localhost/application/index/index I get:

index(resolves to invalid controller class or alias: index)

if I change this:

'application' => array(
            'type'    => 'Zend\Mvc\Router\Http\Literal',
            'options' => array(
                'route'    => '/application',
                'defaults' => array(
                    '__NAMESPACE__' => 'Application\Controller',
                    'controller'    => 'Index',
                    'action'        => 'index',
                ),
            ),

to this:

'application' => array(
            'type'    => 'Zend\Mvc\Router\Http\Literal',
            'options' => array(
                'route'    => '/application',
                'defaults' => array(
                    'controller'    => 'Application\Controller\Index',
                    'action'        => 'index',
                ),
            ),

As you know definitely for http://localhost/application it will work fine like home url

if I use this:

    'controllers'  => array(
    'invokables' => array(
        'index'   => 'Application\Controller\IndexController',
    ),
),

as you know the configurations will merge and I should have just one index controller in the project.

Why the line '__NAMESPACE__' => 'Application\Controller', be ignored and it looks for just Index or index in the controllers array which no exist??

EDIT:

With comparing to other projects I added this to Application/Module.php :

public function onBootstrap(MvcEvent $e)
{
    $eventManager        = $e->getApplication()->getEventManager();
    $moduleRouteListener = new ModuleRouteListener();
    $moduleRouteListener->attach($eventManager);
}

and it works now but I need and explanation. is it the solution? I mean should I add this to one of Module.php files in the project to make routing rules work fine? and why without it the __NAMESPACE__ will be ignored in routing rules?

Answer 1

You already found the solution, adding the ModuleRouteListener is the right thing to do. The explanation can be found in the description of the onRoute method inside this listener:

Listen to the "route" event and determine if the module namespace should be prepended to the controller name.

If the route match contains a parameter key matching the MODULE_NAMESPACE constant, that value will be prepended, with a namespace separator, to the matched controller parameter.