Laravel Lumen: RESTful trait

RestControllerTrait.php

<?php 

namespace App\Http\Controllers;

use Illuminate\Http\Request;

trait RestControllerTrait {

	public function index() {
		$model = self::MODEL;
		return $this->successResponse($model::all());
	}

	public function show($id) {
	
		$model = self::MODEL;
		if ($data = $model::find($id)) {
			return $this->successResponse($data);
		}
		return $this->notFoundResponse();
	}

	public function store(Request $request) {
	
		$model = self::MODEL;
		try {
		
			$v = \Validator::make($request->all(), $this->validationRules);
		
			if ($v->fails()) {
				throw new \Exception('ValidationException');
			}
		
			$data = $model::create($request->all());
			return $this->successResponse($data);
		} catch (\Exception $exception) {
			$data = ['errors' => $v->errors(), 'exception' => $exception->getMessage()];
			return $this->errorResponse($data);
		}
	}

	public function update(Request $request, $id) {
	
		$model = self::MODEL;
		
		if(!$data = $model::find($id)) {
			return $this->notFoundResponse();   
		}
		
		try {
		
			$v = \Validator::make($request->all(), $this->validationRules);
		
			if($v->fails()) {
				throw new \Exception("ValidationException");
			}
		
			$data->fill($request->all());
			$data->save();
		
			return $this->successResponse($data);
		} catch(\Exception $exception) {
			$data = ['errors' => $v->errors(), 'exception' => $exception->getMessage()];
			return $this->errorResponse($data);
		}
	}

	public function destroy($id) {
	
		$model = self::MODEL;
	
		if (!$data = $model::find($id)) {
			return $this->notFoundResponse();
		}
	
		$data->delete();
		return $this->deleteResponse();
	}

	protected function successResponse($data) {
	
		$response = [
			'code' => 200,
			'status' => 'success',
			'data' => $data
		];
		return response()->json($response, $response['code']);
	}

	protected function notFoundResponse() {
	
		$response = [
			'code' => 404,
			'status' => 'error',
			'data' => 'Resource Not Found',
			'message' => 'Not Found'
		];
		return response()->json($response, $response['code']);
	}


	public function deleteResponse() {
	
		$response = [
			'code' => 204,
			'status' => 'success',
			'data' => [],
			'message' => 'Resource Deleted'
		];
		return response()->json($response, $response['code']);
	}

	public function errorResponse($data) {
	
		$response = [
			'code' => 422,
			'status' => 'error',
			'data' => $data,
			'message' => 'Unprocessable Entity' 
		];
		return response()->json($response, $response['code']);
	}
}

BookController.php

<?php 

namespace App\Http\Controllers;

use Laravel\Lumen\Routing\Controller as BaseController;

class BookController extends BaseController {

	use RestControllerTrait;

	const MODEL = 'App\Models\Book';

	protected $validationRules = [	
					'title' => 'required', 
					'author' => 'required', 
					'isbn' => 'required'
				];
}

routes.php

<?php

/*
|--------------------------------------------------------------------------
| Application Routes
|--------------------------------------------------------------------------
|
| Here is where you can register all of the routes for an application.
| It is a breeze. Simply tell Lumen the URIs it should respond to
| and give it the Closure to call when that URI is requested.
|
*/


function rest($path, $controller, $groupPrefix = 'api/v1') {

	global $app;
	$app->group(['prefix' => $groupPrefix], function() use ($app, $path, $controller) {
		$app->get($path, $controller."@index");
		$app->get($path."/{id}", $controller."@show");
		$app->post($path, $controller."@store");
		$app->put($path."/{id}", $controller."@update");
		$app->delete($path."/{id}", $controller."@destroy");
	});
}

rest('/book', '\App\Http\Controllers\BookController');

$app->get('/', function() use ($app) {
	return $app->version();
});