ZF2 Dependency Injection onto Controller objects without the Service Locator - php

Question

I have been doing a read up on ZF2 Service Locator component and could say I understand how its being used. I have, however, a question which I think its silly but it wouldn't hurt to ask.
I want to have a namespace inside my Module called Component where I can put generic code in like say FunctionsComponent.php, MailerComponent.php or ExcelComponent.php. This would allow me to do some stuff inside my controllers.
What I would like to tryout is to have an ability to have controllers define the components they are interested to use (see below):
class SalesController extends AbstractController
{
protected $components = ['Excel'];
//In some action
public function exportAction()
{
$data = ['data to be exported'];
/**
$data : data to be exported
boolean : Whether to force download or save the file in a dedicated location
*/
$this->Excel->export($data, true);
}
}
The idea is to create a ComponentCollection that perhaps implements the FactoryInterface or ServiceLocatorInterface and then let it check each controller when the MvcEvent has been triggered inside my Module class and have the ComponentCollection inject all the controller component and make them accessible without using the service locator as shown below:
$excel = $sm->get('Application\Component\Excel');
I am well aware that this may seem like a daunting ask but I feel like the best way to learn a framework among other things is to play around with it and try to do the unimaginable.

Answer 1

You should create a BaseController somewhere and then extend all your Controllers from BaseController. Then you can inject your dependencies in your BaseController and use anywhere in kids. For example, I am doing this in my Controller to set head title:
<?php
namespace Application\Controller;
use Zend\Mvc\Controller\AbstractActionController;
class BaseController extends AbstractActionController
{
/**
* Sets the head title for every page
*
* #param string $title
*/
public function setHeadTitle($title)
{
$viewHelperManager = $this->getServiceLocator()->get('ViewHelperManager');
// Getting the headTitle helper from the view helper manager
$headTitleHelper = $viewHelperManager->get('headTitle');
// Setting a separator string for segments
$headTitleHelper->setSeparator(' - ');
// Setting the action, controller, module and site name as title segments
$siteName = 'Ribbon Cutters';
$translator = $this->getServiceLocator()->get('translator');
$title = $translator->translate($title);
$headTitleHelper->append(ucfirst($title));
$headTitleHelper->append($siteName);
}
}
Instead of defining methods, you can define properties.
public $headTitleHelper
and assign it in constructor of BaseController
$this->headTitleHelper = $this->getServiceLocator()->get('ViewHelperManager')->get('headTitle');
Now you can use $this->headTitleHelper in child controllers.
And then
<?php
namespace Application\Controller;
use Zend\View\Model\ViewModel;
use Application\Controller\BaseController;
class IndexController extends BaseController
{
/**
* Property for setting entity manager of doctrine
*/
protected $em;
/**
* landing page
*
* #return ViewModel
*/
public function indexAction()
{
$this->setHeadTitle('Welcome'); // Welcome - Ribbon Cutters
$viewModel = new ViewModel();
return $viewModel;
}
/**
* Sets and gives Doctrine Entity Manager
*
* #return Doctrine Entity Manager
*/
protected function getEntityManager()
{
if (null === $this->em) {
$this->em = $this->getServiceLocator()->get('doctrine.entitymanager.orm_default');
}
return $this->em;
}
}
I think this can help you.