Laravel框架用户登陆身份验证实现方法详解


            本文实例讲述了Laravel框架用户登陆身份验证实现方法。分享给大家供大家参考，具体如下：

laravel中检测用户是否登录，有以下的代码：





if ( !Auth::guest() )

{

  return Redirect::to('/dashboard');

}







那Auth::guest是如何调用的呢？

laravel用了Facade模式，相关门面类在laravel/framework/src/Illuminate/Support/Facades文件夹定义的，看下Auth类的定义：





class Auth extends Facade {

  /**

   * Get the registered name of the component.

   *

   * @return string

   */

  protected static function getFacadeAccessor() { return 'auth'; }

}







laravel框架中，Facade模式使用反射，相关方法其实调用app['auth']中的方法，app['auth']是什么时候创建的呢，

AuthServiceProvider::register方法会注册：





$this->app->bindShared('auth', function($app)

{

  // Once the authentication service has actually been requested by the developer

  // we will set a variable in the application indicating such. This helps us

  // know that we need to set any queued cookies in the after event later.

  $app['auth.loaded'] = true;

  return new AuthManager($app);

});







那为什么最终会调到哪里呢，看下堆栈：





Illuminate\Support\Facades\Auth::guest()

Illuminate\Support\Facades\Facade::__callStatic

Illuminate\Auth\AuthManager->guest()

Illuminate\Support\Manager->__call

public function __call($method, $parameters)

{

    return call_user_func_array(array($this->driver(), $method), $parameters);

}







看下driver的代码：





public function driver($driver = null)

{

    $driver = $driver ?: $this->getDefaultDriver();

    // If the given driver has not been created before, we will create the instances

    // here and cache it so we can return it next time very quickly. If there is

    // already a driver created by this name, we'll just return that instance.

    if ( ! isset($this->drivers[$driver]))

    {

      $this->drivers[$driver] = $this->createDriver($driver);

    }

    return $this->drivers[$driver];

}







没有会调用getDefaultDrive方法





/**

* Get the default authentication driver name.

*

* @return string

*/

public function getDefaultDriver()

{

    return $this->app['config']['auth.driver'];

}







最终调用的是配置文件中配置的driver，如果配的是





'driver' => 'eloquent'







则调用的是





public function createEloquentDriver()

{

    $provider = $this->createEloquentProvider();

    return new Guard($provider, $this->app['session.store']);

}







所以Auth::guest最终调用的是Guard::guest方法

这里的逻辑先从session中取用户信息，奇怪的是session里只保存的是用户ID，然后拿这个ID来从数据库中取用户信息





public function user()

{

    if ($this->loggedOut) return;

    // If we have already retrieved the user for the current request we can just

    // return it back immediately. We do not want to pull the user data every

    // request into the method because that would tremendously slow an app.

    if ( ! is_null($this->user))

    {

      return $this->user;

    }

    $id = $this->session->get($this->getName());

    // First we will try to load the user using the identifier in the session if

    // one exists. Otherwise we will check for a "remember me" cookie in this

    // request, and if one exists, attempt to retrieve the user using that.

    $user = null;

    if ( ! is_null($id))

    {

      //provider为EloquentUserProvider

     $user = $this->provider->retrieveByID($id);

    }

    // If the user is null, but we decrypt a "recaller" cookie we can attempt to

    // pull the user data on that cookie which serves as a remember cookie on

    // the application. Once we have a user we can return it to the caller.

    $recaller = $this->getRecaller();

    if (is_null($user) && ! is_null($recaller))

    {

      $user = $this->getUserByRecaller($recaller);

    }

    return $this->user = $user;

}







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希望本文所述对大家基于Laravel框架的PHP程序设计有所帮助。