Laravel polymorphic relations: Passing model to co

问题:

I want to use a single controller to save my comments for multiple models. So I created the CommentController, with the following store method:

public function store(Teacher $teacher, Request $request)
    {    
        $input = $request->all();

        $comment = new Comment();

        $comment->user_id = Auth::user()->id;
        $comment->body = $input['body'];

        $teacher->comments()->save($comment);

        return redirect()->back();
    }

In my view, I have:

{!! Form::open([
    'route' => ['teachers.comments.store', $teacher->id]
]) !!}

This is working. If I want to use the same CommentController to store the comments for a school, how should I modify the store method of the controller?

回答1:

Im not sure if this is the Laravel convension, but i have done the following:

Made a route:

Route::post('/Comment/{model}/{id}', [
    // etc
]);

Then in the controller get the model and check against an array of allowed models, pass the id through and attach:

public function store(Request $request, $model, $id) {
    $allowed = ['']; // list all models here

    if(!in_array($model, $allowed) {
        // return redirect back with error
    }

    $comment = new Comment();
    $comment->user_id = $request->user()->id;
    $comment->commentable_type = 'App\\Models\\'.$model;
    $comment->commentable_id = $id;
    $comment->body = $request->body;
    $comment->save();

    return redirect()->back();
}

Like I say, there is most likely a much better way to accomplish, but this is how I've done it. It keeps it short and sweet and checks if the model can take a comment.

回答2:

Adam's solution is great, but I would not hard-code the model's namespace that way. Instead, what I would do is make use of Laravel's Relation::morphMap(), you can check it out here: https://laravel.com/docs/5.6/eloquent-relationships#polymorphic-relations

That way, you will also make your database entries more readable. I recommend using a service provider to map the morphs.

Also, the Model base class has a getMorphClass() method, so instead of $comment->commentable_type = 'App\\Models\\'.$model; I would use $comment->commentable_type = $model->getMorphClass();

That way you integrate Laravel's logic into your code.

回答3:

I implemented this way if you want, according to me it's the one of the bests way to do that.

// Route::post('/comments/{model}/{id}', 'CommentController@store');
class CommentController extends Controller {

protected $model;

public function __construct()
{
    $this->model = Relation::getMorphedModel(
        request()->route()->parameter('model')
    );
}

/**
 * Store a newly created resource in storage.
 *
 * @param  \Illuminate\Http\Request  $request
 * @return \Illuminate\Http\Response
 */
public function store(Request $request)
{
    dd($this->model); // return 'App\Post' or null
}

}