Symfony的错误登录

Question

在Symfony的，我想创建一个loginpage，但我得到了以下错误：

Variable "error" does not exist in QuizBundle:Default:welcome.html.twig at line 37

有人可以帮助我？ 这里是我的代码：

类：

class SecurityController extends Controller 
{ 
    public function indexAction($name) 
    { 
     return $this->render('', array('name' => $name)); 
    } 

    /** 
    * @Route("/welcome", name="welcome") 
    */ 
    public function welcomeAction(Request $request) 
    { 
     $authenticationUtils = $this->get('security.authentication_utils'); 

     // get the login error if there is one 
     $error = $authenticationUtils->getLastAuthenticationError(); 

     // last username entered by the user 
     $lastUsername = $authenticationUtils->getLastUsername(); 



     return $this->render('@Quiz/Default/welcome.html.twig', array(
       // last username entered by the user 
       'last_username' => $lastUsername, 
       'error'   => $error, 
      ) 
     ); 
    } 
} 

嫩枝文件：

<div id="loginfields" style="display: none"> 
       {% if error %} 
        <div>{{error.messageKey|trans(error.messageData, 'security')}}</div> 
       {% endif %} 

       <form class="form-signin" action="{{path('welcome')}}" method="post"> 
        <h2 class="form-signin-heading">Please sign in</h2> 
        <label class="sr-only" for="username">Username:</label> 
        <input type="text" id="username" placeholder="Username" class="form-control" name="_username" value="{{ last_username }}"/> 

        <label class="sr-only" for="password">Password:</label> 
        <input type="password" id="password" class="form-control" placeholder="Password" name="_password" /> 
        <input type="hidden" name="_target_path" value="/admin" /> 

        <button class="btn btn-lg btn-primary btn-block" type="submit">Sign in</button> 
       </form> 
      </div> 

Security.yml

security: 
    encoders: 
      QuizBundle\Entity\User: plaintext 

    providers: 
      our_db_provider: 
       entity: 
        class: QuizBundle:User 

    firewalls: 
      main: 
       anonymous: ~ 
       form_login: 
        login_path: welcome 
        check_path: welcome 

Answer 1

要使用error变量（或避免异常/错误，当您尝试使用也许不会存在的变量），你需要检查它是否存在这样的：在define Twig documentation

{% if error is defined %} 
    <div>{{error.messageKey|trans(error.messageData, 'security')}}</div> 
{% endif %} 

更多的相关信息。