Basz feature/accepted model controller plugin

[Freeaqingme]

This is a follow up of #2405: https://github.com/zendframework/zf2/pull/2405/files

[Freeaqingme]

@weierophinney I incorporated @basz 's feedback. Up for review.

[Freeaqingme]

Rebased!

[Freeaqingme]

This plugin allows one to easily and safely define what View Model type should be used based on the accept header string.

<?php
public function foobarAction()
{
   $arr = array(
        'Zend\View\Model\JsonModel' => array(
            'application/json',
            'application/javascript'
        ),
        'Zend\View\Model\FeedModel' => array(
            'application/rss+xml',
            'application/atom+xml'
        ),
        'Zend\View\Model\ViewModel' => '*/*'
    );


    $this->request->getHeaders()->addHeader($header);
    $viewModel = $this->acceptantViewModelSelector($arr);
    //    $viewModel now is an instance of Zend\View\Model\FeedModel
}
?>

Generally this mapping array will be defined on a controller level, or even application wide level. But it does allow one to deviate from the defaults.

The need for this functionality arises because of multiple difficulties currently experienced with accept header handling and view model selection:

• The default render strategy strategy kicks in only after the controller has dispatched. However, based on the accept header it may be required to perform different actions.
• The current render strategy setup is not capable of handling accept headers like /.
• Because render strategies are defined on an application-wide level, security issues arise, eg. JsonStrategy security fix #2410

[akrabat]

I think this should be AcceptedViewModelSelector

[weierophinney]

My only concern at this point is whether or not the ViewManager should allow registering strategies at initialization or not.

Removing that functionality is technically a BC break, but, as you and others have noted, it could also be a potential security issue.

I'll ask the security team their opinion. Otherwise, this is a great set of functionality, and I look forward to merging it and using it.

[Maks3w]

missed @ in front of return

[juriansluiman]

Would it be possible to make some use cases a bit easier to work with? In my particular case, I have quite often support for a Json model when application/json or application/javascript is requested, all other types are simply handled the same way. In case JSON is requested, it will always be for q=1 (so at top-priority).

I could imagine a simple way like this:

class MyController
{
  public function fooAction()
  {
    $service = $this->getService();
    $result  = $service->doSomeWork();

    if ($this->accept()->match(array('application/json', 'application/javascript'))) {
      return new JsonModel($result);
    }

    return $this->redirect()->toRoute('foo/bar');
  }
}

I can create my own plugin using Request::match() myself, but it seems something like this could also be implemented in this AcceptableViewModelSelector?

[Maks3w]

@basz @Freeaqingme Don't forget send a PR to zf2-documentation documenting the plugn!

[basz]

I can start with this... but not within a few days...

[Freeaqingme]

@juriansluiman We could indeed implement such functionality. However, it should be 100% configurable, and may need a little bit more thought put into it. Lets get this baby done first, then look what else we could do.

@Maks3w No worries, you're getting your docs! ;)

[weierophinney]

@Freeaqingme As noted yesterday on IRC, we'll need to merge this against the master branch as well. The only way I see to do this is to merge a range of commits or cherry-pick. My question is: do you want to do this, or are you okay with somebody else doing it? Both will rewrite history, so the question is if you want that rewrite to happen in your own branch, or in mine.