How to use dependency injection in Zend Framework?

Question

Currently I am trying to learn the Zend Framework and therefore I bought the book \"Zend Framework in Action\".

In chapter 3, a basic model and controller is introduced

Answer 1

Ok, this is how I did it:

As IoC Framework I used this component of the symfony framework (but I didnt download the latest version, I used an older one I used on projects before... keep that in mind!). I added its classes under /library/ioc/lib/.

I added these init function in my Bootstrap.php in order to register the autoloader of the IoC framework:

protected function _initIocFrameworkAutoloader()
{
    require_once(APPLICATION_PATH . '/../library/Ioc/lib/sfServiceContainerAutoloader.php');

    sfServiceContainerAutoloader::register();
}

Next, I made some settings in application.ini which set the path to the wiring xml and allow to disable automatic dependency injection e. g. in unit tests:

ioc.controllers.wiringXml = APPLICATION_PATH "/objectconfiguration/controllers.xml"
ioc.controllers.enableIoc = 1

Then, I created a custom builder class, which extends sfServiceContainerBuilder and put it under /library/MyStuff/Ioc/Builder.php. In this test project I keep all my classes under /library/MyStuff/.

class MyStuff_Ioc_Builder extends sfServiceContainerBuilder
{
  public function initializeServiceInstance($service)
  {
      $serviceClass = get_class($service);
      $definition = $this->getServiceDefinition($serviceClass);


    foreach ($definition->getMethodCalls() as $call)
    {
      call_user_func_array(array($service, $call[0]), $this->resolveServices($this->resolveValue($call[1])));
    }

    if ($callable = $definition->getConfigurator())
    {
      if (is_array($callable) && is_object($callable[0]) && $callable[0] instanceof sfServiceReference)
      {
        $callable[0] = $this->getService((string) $callable[0]);
      }
      elseif (is_array($callable))
      {
        $callable[0] = $this->resolveValue($callable[0]);
      }

      if (!is_callable($callable))
      {
        throw new InvalidArgumentException(sprintf('The configure callable for class "%s" is not a callable.', get_class($service)));
      }

      call_user_func($callable, $service);
    }

  }
}

Last, I created a custom controller class in /library/MyStuff/Controller.php which all my controllers inherit from:

class MyStuff_Controller extends Zend_Controller_Action {
    /**
     * @override
     */
    public function dispatch($action)
    {
        // NOTE: the application settings have to be saved 
        // in the registry with key "config"
        $config = Zend_Registry::get('config');

        if($config['ioc']['controllers']['enableIoc'])
        {
            $sc = new MyStuff_Ioc_Builder();

            $loader = new sfServiceContainerLoaderFileXml($sc);
            $loader->load($config['ioc']['controllers']['wiringXml']);

            $sc->initializeServiceInstance($this);
        }

        parent::dispatch($action);
    }
}

---

What this basically does is using the IoC Framework in order to initialize the already created controller instance ($this). Simple tests I did seemed to do what I want... let´s see how this performs in real life situations. ;)

It´s still monkey patching somehow, but the Zend Framework doesn´t seem to provide a hook where I can create the controller instance with a custom controller factory, so this is the best I came up with...