Laravel 5.2 Auth门面和Auth :: guard（$ guard）

Question

I am new to Laravel. I was browsing the default authenticate middleware and I see that it is using:

Auth::guard($guard)->guest()

to check if the user is a guest.

The documentation at https://laravel.com/docs/5.2/authentication#retrieving-the-authenticated-user tells that one can use:

Auth::check()

To figure out if a user is authenticated. (I image this is opposite of guest() ?

I tried changing the default code to use

Auth::guest()

and I am getting exactly the same result.

My question is, what is the difference between having guard($guard)-> or not in this case?

A related question. Is guest() completely opposite of check() or are there circumstances where these may return same results?

Thanks!

Answer 1

The authenticate middleware allows you to specify what type of auth guard you want to use. Laravel 5.2 comes with two out of the box, 'web' and 'api' .

The Auth facade uses the 'web' guard by default if none is specified. So for example: Auth::user() is doing this by default: Auth::guard('web')->user()

The other auth driver out of the box called 'api' . So for example you can call your middleware like this: $this->middleware('auth:api');

This will check that the user is authenticated by api_token instead of session. Then you can get an instance of the user by Auth::guard('api')->user() instead of Auth::user() which is the same as Auth::guard('web')->user()

You would use this if your application has an API endpoint allowed for logged in users only. then a user can make a request like yourapp.com/api-method?api_token=blahblah. Then you can use the 'api' auth guard to authenticate and grab the logged in User.

I found this tutorial pretty useful in setting it up: http://learninglaravel.net/multiple-authentication-guard-drivers-including-api-in-laravel-52

And to answer your second question. Yes guest() is just the opposite of check(). check out laravel\\framework\\src\\Illuminate\\Auth\\GuardHelpers.php

Answer 2

Well there is no difference - if you examine the Auth facade than you'll see that the Auth::guest() is a shorthand of the Auth::guard($guard)->guest() . Auth::check() is a:

/**
 * Determine if the current user is authenticated.
 *
 * @return bool
 */
public function check()
{
    return ! is_null($this->user());
}

and Auth::guest() is a opposit of Auth::check() :

/**
 * Determine if the current user is a guest.
 *
 * @return bool
 */
public function guest()
{
    return ! $this->check();
}

Answer 3

Firstable I wan to show you how Auth::guard()->guest() work.

/**
 * Attempt to get the guard from the local cache.
 *
 * @param  string  $name
 * @return \Illuminate\Contracts\Auth\Guard|\Illuminate\Contracts\Auth\StatefulGuard
 */ 

public function guard($name = null)
{
    $name = $name ?: $this->getDefaultDriver();

    return isset($this->guards[$name])
                ? $this->guards[$name]
                : $this->guards[$name] = $this->resolve($name);
}

The guard Method will Return to \\Illuminate\\Contracts\\Auth\\Guard or \\Illuminate\\Contracts\\Auth\\StatefulGuard this is two types of Interface, it will help laravel select guest() or check() method. If you have been used Auth:check() and Auth::guest() but it only show the same Result. Maybe you were Set the attemp Method in login() like this code below

Auth::attempt(['email'=>$email,'password'=>$password],$rememberMe,true)

You just need to Remove true Argument, It will Return right Value like you desire