How do you force a JSON response on every response in Laravel?

Question

I'm trying to build a REST api using Laravel Framework, I want a way to force the API to always responed with JSON not by doing this manulaly like:

return Response::json($data);

In other words I want every response to be JSON. Is there a good way to do that?

Update: The response must be JSON even on exceptions like not found exception.

Answer 1

Create a middleware as suggested by Alexander Lichter that sets the Accept header on every request:

<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;

class ForceJsonResponse
{
    /**
     * Handle an incoming request.
     *
     * @param  \Illuminate\Http\Request  $request
     * @param  \Closure  $next
     * @return mixed
     */
    public function handle(Request $request, Closure $next)
    {
        $request->headers->set('Accept', 'application/json');

        return $next($request);
    }
}

Add it to $routeMiddleware in the app/Http/Kernel.php file:

protected $routeMiddleware = [
    (...)
    'json.response' => \App\Http\Middleware\ForceJsonResponse::class,
];

You can now wrap all routes that should return JSON:

Route::group(['middleware' => ['json.response']], function () { ... });

Edit: For Laravel 6.9+

Give the json.response middleware priority over other middlewares - to handle cases where the request is terminated by other middlewares (such as the Authorize middleware) before you get to set the Accept header.

To do this - override the constructor of you App\Http\Kernel class (app/Http/Kernel.php) with:

    public function __construct( Application $app, Router $router ) {
        parent::__construct( $app, $router );
        $this->prependToMiddlewarePriority(\App\Http\Middleware\ForceJsonResponse::class);
    }

Answer 2

Laravel Middleware is Extremely useful in this use case.

1. Make JsonResponseMiddleware middleware.

php artisan make:middleware JsonResponseMiddleware

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Routing\ResponseFactory;

class JsonResponseMiddleware
{
    /**
     * @var ResponseFactory
     */
    protected $responseFactory;

    /**
     * JsonResponseMiddleware constructor.
     */
    public function __construct(ResponseFactory $responseFactory)
    {
        $this->responseFactory = $responseFactory;
    }

    /**
     * Handle an incoming request.
     *
     * @param Request $request
     * @param Closure $next
     * @return mixed
     */
    public function handle(Request $request, Closure $next)
    {
        // First, set the header so any other middleware knows we're
        // dealing with a should-be JSON response.
        $request->headers->set('Accept', 'application/json');

        // Get the response
        $response = $next($request);

        // If the response is not strictly a JsonResponse, we make it
        if (!$response instanceof JsonResponse) {
            $response = $this->responseFactory->json(
                $response->content(),
                $response->status(),
                $response->headers->all()
            );
        }

        return $response;
    }
}

2. Registor middleware in App\Http\Kernel.php

protected $middlewareGroups = [

        'api' => [
            ...
            ....
            /// Force to Json response (Our created Middleware)
            \App\Http\Middleware\JsonResponseMiddleware::class,
        ],


        'web' => [
            ...
            ....
            /// Add Here as well if we want to force response in web routes too.
        ],
]

Now we will receive every response in JSON only.

Please note that: Even exceptions will respond in JSON format