Unresolvable dependency resolving [Parameter #0 [ <required> $name ]]

Question

Warning: This question is Laravel 4 specific.

I've been using Facades in my controllers before. Therefore I know the code is working. Now I need to introduce dependency injection for various reasons.

After refactoring the controller I get following error:

Illuminate \ Container \ BindingResolutionException

Unresolvable dependency resolving [Parameter #0 [ $name ]].

I can't figure out where the problem is. The Error message seems cryptic to me and I don't understand it. (I don't see any problem with my __constructor parameters since I've registered the binding for the HelpersInterface)

Here are the important parts of my code:

File: app/start/global.php

<?php   // ...   App::bind('Acme\Interfaces\HelpersInterface', 'Acme\Services\Helpers'); 

File: composer.json

// ...   "autoload": {     // ...     "psr-0": {         "Acme": "app/"     } },   // ... 

File: app/Acme/Controllers/BaseController.php

<?php namespace Acme\Controllers;   use Carbon\Carbon; use Controller; use Illuminate\Foundation\Application as App; use Illuminate\View\Factory as View; use Acme\Interfaces\HelpersInterface as Helpers; use Illuminate\Http\Response;   class BaseController extends Controller {       /**      * @var \Illuminate\Foundation\Application      */     private $app;       /**      * @var \Carbon\Carbon      */     private $carbon;       /**      * @var \Illuminate\View\Factory      */     private $view;       /**      * @var \Acme\Interfaces\HelpersInterface      */     private $helpers;       function __construct(App $app, Carbon $carbon, View $view, Helpers $helpers)     {         $this->app = $app;         $this->carbon = $carbon;         $this->view = $view;         $this->helpers = $helpers;           $lang = $this->app->getLocale();         $now = $this->carbon->now();           $this->view->share('lang', $lang);         $this->view->share('now', $now);     }       /**      * Missing Method      *      * Abort the app and return a 404 response      *      * @param array $parameters      * @return Response      */     public function missingMethod($parameters = array())     {         return $this->helpers->force404();     }   } 

File: app/Acme/Services/Helpers.php

<?php namespace Acme\Services;  use Illuminate\Config\Repository as Config; use Illuminate\Database\Connection as DB; use Illuminate\Http\Request; use Illuminate\Routing\Redirector as Redirect; use Illuminate\Session\Store as Session; use Illuminate\Support\Facades\Response; use Illuminate\Translation\Translator as Lang; use Illuminate\View\Factory as View; use Acme\Interfaces\MockablyInterface; use Monolog\Logger as Log;  class Helpers implements HelpersInterface {  // ...      public function __construct(         Config $config,         Lang $lang,         View $view,         MockablyInterface $mockably,         Log $log,         Request $request,         Session $session,         DB $db,         Redirect $redirect,         Response $response     ) {         // ...     }  // ...  } 

File: app/Acme/Providers/HelpersServiceProvider.php

<?php namespace Acme\Providers;  use Illuminate\Support\ServiceProvider; use Acme\Services\Helpers;  class HelpersServiceProvider extends ServiceProvider {  private $db; private $defaultDbConnection;  protected function init() {     $this->db = $this->app['db'];     $this->defaultDbConnection = $this->db->getDefaultConnection(); }  public function register() {     $this->init();      $this->app->bind('helpers', function ()     {         return new Helpers(             $this->app['config'],             $this->app['translator'],             $this->app['view'],             $this->app['mockably'],             $this->app->make('log')->getMonolog(),             $this->app['request'],             $this->app['session.store'],             $this->db->connection($this->defaultDbConnection),             $this->app['redirect'],             $this->app['Illuminate\Support\Facades\Response']         );     }); } 

Answer 1

For me it was just a matter of running

php artisan optimize:clear