Laravel - How to show JSON when API route is wrong or not found?

Question

I am using Laravel to create API and postman to check my API. When I am putting a right URL in postman it is working fine, but when I am putting a wrong URL it is showing HTML and Laravel 404 error, I want to return a message in JSON format, how would I do that.

Answer 1

You should add the Accept header set to application/json to your postman request in the headers tab like so: :

This will tell Laravel that you want a json response, instead of HTML. The same would apply for any request inside your application.

As you can see, this is checked on the Illuminate\Http\Response object, when the payload is set, it checks if it should be morphed to JSON:

/**
 * Set the content on the response.
 *
 * @param  mixed  $content
 * @return $this
 */
public function setContent($content)
{
    $this->original = $content;

    // If the content is "JSONable" we will set the appropriate header and convert
    // the content to JSON. This is useful when returning something like models
    // from routes that will be automatically transformed to their JSON form.
    if ($this->shouldBeJson($content)) {
        $this->header('Content-Type', 'application/json');

        $content = $this->morphToJson($content);
    }

    // If this content implements the "Renderable" interface then we will call the
    // render method on the object so we will avoid any "__toString" exceptions
    // that might be thrown and have their errors obscured by PHP's handling.
    elseif ($content instanceof Renderable) {
        $content = $content->render();
    }

    parent::setContent($content);

    return $this;
}

You can find the code here.

Hope this helps you.

Answer 2

AS I understand OP's requriement, wants to override the the Not Found exception rendering behaviour into a JSON response.

Laravel actually generates an exception of type NotFoundHttpException and render it. To prevent this behaviour you can do this.

In 'app\Exceptions\Handler.php', you see a function

 /**
 * Render an exception into an HTTP response.
 *
 * @param  \Illuminate\Http\Request  $request
 * @param  \Exception  $exception
 * @return \Illuminate\Http\Response
 */
public function render($request, Exception $exception)
{
    // comment this line and return JSON Response.
    //return parent::render($request, $exception);

    return json_encode(array("message" => $exception->getMessage())); // or you can 
} 

PS: This is not an ultimate solution, just a workaround if you only want your API to return JSON incase of errors.

Answer 3

You can add route fallback closure to your routes/api.php

Route::fallback(function(){
     return response()->json(['message' => '<your message>'], 404);
});

Answer 4

https://laravel.com/docs/9.x/errors :

use Symfony\Component\HttpKernel\Exception\NotFoundHttpException;
 
/**
 * Register the exception handling callbacks for the application.
 *
 * @return void
 */
public function register()
{
    $this->renderable(function (NotFoundHttpException $e, $request) {
        if ($request->is('api/*')) {
            return response()->json([
                'message' => 'Record not found.'
            ], 404);
        }
    });
}