event that adds a parameter to routing - zend-framework2

Question

Is it possible to hook up (ideally in the controller) to add an additional parameter to routing?
I know that sounds unclear and at first glance it may sounds ridiculous - because to reach the controller we already must have routing. But I want to change only default variables.
I'll try to explain what I want to achieve:
Config:
return [
'router' => [
'routes' => [
'some' => [
'type' => 'Zend\Mvc\Router\Http\Segment',
'options' => [
'route' => '/some/:project',
'defaults' => [
'__NAMESPACE__' => 'Some\Controller',
'controller' => 'Some\Controller\Some',
'action' => 'some',
'extra' => 'default-value'
],
],
]
]
]
];
Controller:
class SomeController extends AbstractActionController {
protected $project = null;
public function setEventManager(EventManagerInterface $events)
{
parent::setEventManager($events);
$controller = $this;
$events->attach(
'dispatch', function (\Zend\Mvc\MvcEvent $e) use ($controller) {
$params = $e->getRouteMatch()->getParams();
$this->project = $params['project'] ;
// and there should be something that I want to
// achieve but do not know how (and if it is possible)
if ($this->project == 1) {
// magic action which modify config default param
// "extra" from "default-value" to "changed-value"
}
return;
}, 50
);
}
protected function attachDefaultListeners()
{
parent::attachDefaultListeners();
$eventManager = $this->getEventManager();
$eventManager->attach(
\Zend\Mvc\MvcEvent::EVENT_DISPATCH,
function(\Zend\Mvc\MvcEvent $event) {
$ViewModel = $event->getResult();
if ($ViewModel instanceof \Zend\View\Model\ViewModel) {
$ViewModel->setVariable('project',$this->project);
}
},
-99);
}
public function someAction() {
echo $this->params()->fromRoute("extra"); // return "default-value";
// but i want
echo $this->params()->fromRoute("extra"); // return "changed-value";
return new ViewModel();
}
}
View
<?php
echo "project: ".$this->project;
echo $this->url('some',['project'=>1]); // result: "/some/1"
I know this seems very strange. But for some reason (readable links, seo) is necessary to me.

Answer 1

Are you sure, you want to change the default param?
if ($this->project == 1) {
$e->getRouteMatch()->setParam('extra', 'changed-value');
}
You can set default params globally for assembling:
$serviceLocator->get('router')->setDefaultParam('extra', 'changed-value');
There is no way to change the defaults-Property of Zend\Mvc\Router\Http\Segment
If you really need it you must extend this class (but I would not recommend that, because I think your approach is already wrong)