做專案的時候，使用者認證幾乎是必不可少的，如果我們的專案由於一些原因不得不使用 users 之外的使用者表進行認證，那麼就需要多做一點工作來完成這個功能。
現在假設我們只需要修改登入使用者的表，表名和表結構都與框架預設的表users不同，文件沒有教我們如何去做，但是別慌，稍微看下框架實現使用者認證的原始碼就能輕鬆實現。
首先，自定義一張表用來登入，表結構和模擬資料如下：
表 admins
| id | login_name | login_pass |
|---|---|---|
| 1 | admin | $2y$10$2MUhp7b6ghVOngb/.b/x6uuEW/yL3FqPKJztawrM0U577Clf07xda |
從配置檔案入手
使用者認證相關的配置都儲存在config/auth.php檔案中，先來看看配置檔案的內容：
<?php
return [
/*
|--------------------------------------------------------------------------
| Authentication Defaults
|--------------------------------------------------------------------------
|
| This option controls the default authentication "guard" and password
| reset options for your application. You may change these defaults
| as required, but they're a perfect start for most applications.
|
*/
'defaults' => [
'guard' => 'web',
'passwords' => 'users',
],
/*
|--------------------------------------------------------------------------
| Authentication Guards
|--------------------------------------------------------------------------
|
| Next, you may define every authentication guard for your application.
| Of course, a great default configuration has been defined for you
| here which uses session storage and the Eloquent user provider.
|
| All authentication drivers have a user provider. This defines how the
| users are actually retrieved out of your database or other storage
| mechanisms used by this application to persist your user's data.
|
| Supported: "session", "token"
|
*/
'guards' => [
'web' => [
'driver' => 'session',
'provider' => 'users',
],
'api' => [
'driver' => 'passport',
'provider' => 'users',
],
],
/*
|--------------------------------------------------------------------------
| User Providers
|--------------------------------------------------------------------------
|
| All authentication drivers have a user provider. This defines how the
| users are actually retrieved out of your database or other storage
| mechanisms used by this application to persist your user's data.
|
| If you have multiple user tables or models you may configure multiple
| sources which represent each model / table. These sources may then
| be assigned to any extra authentication guards you have defined.
|
| Supported: "database", "eloquent"
|
*/
'providers' => [
'users' => [
'driver' => 'eloquent',
'model' => App\User::class,
],
// 'users' => [
// 'driver' => 'database',
// 'table' => 'users',
// ],
],
/*
|--------------------------------------------------------------------------
| Resetting Passwords
|--------------------------------------------------------------------------
|
| You may specify multiple password reset configurations if you have more
| than one user table or model in the application and you want to have
| separate password reset settings based on the specific user types.
|
| The expire time is the number of minutes that the reset token should be
| considered valid. This security feature keeps tokens short-lived so
| they have less time to be guessed. You may change this as needed.
|
*/
'passwords' => [
'users' => [
'provider' => 'users',
'table' => 'password_resets',
'expire' => 60,
],
],
];
預設使用的守衛是web，而web守衛使用的認證驅動是session，使用者提供器是users。假設我們的需求只是將使用者的提供器由users改為admins，那麼我們需要做兩步操作：
- 修改預設的使用者提供器，將
provider=>'users'改為provider=>'admins''guards' => [ 'web' => [ 'driver' => 'session', 'provider' => 'users', ], ], - 配置
admins提供器，假設依舊使用eloquent作為驅動，並建立好了admins表的模型'providers' => [ 'admins' => [ 'driver' => 'eloquent', 'model' => App\Admin::class ] ],
使用Auth門面的attempt方法進行登入
SessionGuard 中的attempt方法：
//Illuminate\Auth\SessionGuard
public function attempt(array $credentials = [], $remember = false)
{
$this->fireAttemptEvent($credentials, $remember);
$this->lastAttempted = $user = $this->provider->retrieveByCredentials($credentials);
// If an implementation of UserInterface was returned, we'll ask the provider
// to validate the user against the given credentials, and if they are in
// fact valid we'll log the users into the application and return true.
if ($this->hasValidCredentials($user, $credentials)) {
$this->login($user, $remember);
return true;
}
// If the authentication attempt fails we will fire an event so that the user
// may be notified of any suspicious attempts to access their account from
// an unrecognized user. A developer may listen to this event as needed.
$this->fireFailedEvent($user, $credentials);
return false;
}該方法中呼叫 UserProvider 介面的retrieveByCredentials方法檢索使用者，根據我們的配置，UserProvider介面的具體實現應該是EloquentUserProvider，因此，我們定位到EloquentUserProvider的retrieveByCredentials方法：
//Illuminate\Auth\EloquentUserProvider
public function retrieveByCredentials(array $credentials)
{
if (empty($credentials) ||
(count($credentials) === 1 &&
array_key_exists('password', $credentials))) {
return;
}
// First we will add each credential element to the query as a where clause.
// Then we can execute the query and, if we found a user, return it in a
// Eloquent User "model" that will be utilized by the Guard instances.
$query = $this->createModel()->newQuery();
foreach ($credentials as $key => $value) {
if (Str::contains($key, 'password')) {
continue;
}
if (is_array($value) || $value instanceof Arrayable) {
$query->whereIn($key, $value);
} else {
$query->where($key, $value);
}
}
return $query->first();
}該方法會使用傳入的引數（不包含password）到我們配置的資料表中搜尋資料，查詢到符合條件的資料之後返回對應的使用者資訊，然後attempt方法會進行密碼校驗，校驗密碼的方法為：
//Illuminate\Auth\SessionGuard
/**
* Determine if the user matches the credentials.
*
* @param mixed $user
* @param array $credentials
* @return bool
*/
protected function hasValidCredentials($user, $credentials)
{
return ! is_null($user) && $this->provider->validateCredentials($user, $credentials);
}進一步檢視EloquentUserProvider中的validateCredentials方法
//Illuminate\Auth\EloquentUserProvider
public function validateCredentials(UserContract $user, array $credentials)
{
$plain = $credentials['password'];
return $this->hasher->check($plain, $user->getAuthPassword());
}通過validateCredentials可以看出，提交的認證資料中密碼欄位名必須是password，這個無法自定義。同時可以看到，入參$user必須實現Illuminate\Contracts\Auth\Authenticatable介面（UserContract是別名）。
修改 Admin 模型
Admin模型必須實現Illuminate\Contracts\Auth\Authenticatable介面，可以借鑑一下User模型，讓Admin直接繼承Illuminate\Foundation\Auth\User 就可以，然後重寫getAuthPassword方法，正確獲取密碼欄位：
// App\Admin
public function getAuthPassword()
{
return $this->login_pass;
}不出意外的話，這個時候就能使用admins表進行登入了。
總結
laravel提供了很強的擴充套件性，幾乎一切都可以個性化定製，但是需要我們耐心看看原始碼和文件，程式碼註釋很詳細，這裡只是簡單的介紹了一下自定義使用者登入的表，實際業務需求往往很複雜，需要定製的功能會更多，但是隻要按照框架的規範開發，一切都很簡單。