[5.0] Contextual binding doesn't work with method injection.

[Arhimandril]

Right now contextual binding resolution only works at the constructor level but it should also work with method injection. So, for example, if we have:

$app->when('PostsController')
    ->needs('PostRepositoryInterface')
    ->give('EloquentPostRepository');

then PostsController::__construct(PostRepositoryInterface $posts) will resolve the dependency correctly but PostsController::store(PostRepositoryInterface $posts) will only look for a non-contextual binding and will fail to resolve.

[nmabhinandan]

It would be great to have something like this.

$app->when('PostController@store')
     ->needs('PostRepositoryInterface')
     ->give('EloquentPostRepository');

[hannesvdvreken]

Can you please add a real-life example where you need different implementations of the same parent type injected in different methods of the same class? Thanks!

[robinmitra]

I also posted the same question on Stack Overflow.

Consider the following scenario, which is what I'm currently using for my project's API:

I have a base API controller which implements the CRUD functionalities for various entities (e.g. User, Address, Phone, etc.).

As a simplified example, here is the code for the base controller:

abstract class ApiController {

    protected $repo;

    public function __construct(RepositoryInterface $repo)
    {
        $this->repo = $repo;
    }

    public function index()
    {
        // return a list of records/models (e.g. $this->repo->getAll())
    }

    /**
     * This is using route model (repository to be precise) binding
     */
    public function show($repo)
    {
        // return a record/model (e.g. $repo->getModel())
    }

    /**
     * This is also using route model (repository to be precise) binding
     */
    public function delete($repo)
    {
        // delete a record/model (e.g. $repo->delete())
    }        

}

Each entity's controller (e.g. UsersController) would extend the base controller, inheriting the CRUD functionalities. In the above, I'm using contextual bindings to inject the relevant repository into the __constructor() method (e.g. when UsersController needs RepositoryInterface, give UserRepository). It works beautifully for the index(), show() and delete() methods.

In order to implement store() and update() methods, I would need to inject object for the relevant request class (I have one for create and one for update operation, for each entity).

The problem is, I cannot inject object of the relevant request class into the constructor due to a couple of reasons:

• Automatic validation would be run as described in the request class on each request (e.g. even for index() method!). This is clearly wrong, and validation would obviously fail for index(), show()and delete()methods, since no user input is supplied for them.
• I have different classes for create and update requests, which means I would need to inject object for the relevant class depending on the method (i.e. store() or update()) being run. This cannot be achieved using constructor injection.

If contextual binding also worked for controller methods other than the constructor, I could just inject the relevant request object directly into the method. For example, I could do something like the following:

   ...

    public function store(CreateRequestInterface $request)
    {
        // create a record (e.g. $this->repo->create($request->all()))
    }

    public function update($repo, UpdateRequestInterface $request)
    {
        // create a record (e.g. $repo->update($request->all()))
    }

   ...

Since this doesn't work as of now, I'm using a workaround by declaring a couple of properties $createRequestClass and $updateRequestClass, which I override in children controllers to the relevant request classes. Then, within the store() and update() methods, I manually create the instance of the relevant request class using something like $request = App::make($this->createRequestClass).

If contextual bindings would have worked for methods, even this bit of code would not be been needed and everything would have been beautiful :)

[robinmitra]

Why was this silently closed without further discussion?

[hannesvdvreken]

Because Graham forgot to mention contextual binding is now available in
illuminate/container 5.0
On 7 Feb 2015 08:22, "Robin Mitra" notifications@github.com wrote:

Why was this silently closed without further discussion?

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Reply to this email directly or view it on GitHub
#6177 (comment).

[nmabhinandan]

Thanks for the info @hannesvdvreken

[robinmitra]

@hannesvdvreken wow that's great! Thanks

[chargoy]

@robinmitra Hi! Is it working? Because I have the same issue.

[smallhadroncollider]

I can't get this to work.

The following works (but isn't useful):

$this->app->bind("API\Http\Requests\RequestInterface", "API\Http\Requests\SquareRequest");

This does not:

$this->app->when("API\Http\Controllers\SquaresController")
    ->needs("API\Http\Requests\RequestInterface")
    ->give("API\Http\Requests\SquareRequest");

[refear99]

@smallhadroncollider @hannesvdvreken
I have the same issue.
use bind() works,
but use when->needs->give not working

[smallhadroncollider]

@refear99 I've added a pull request which adds a (currently failing) test for this, so hopefully it might be addressed #8906