yii2 resetful 授权验证详解

<?php
namespace api\models;

use Yii;
use yii\base\Model;
use common\models\User;

/**
 * Login form
 */
class LoginForm extends Model
{
 public $username;
 public $password;

 private $_user;

 const GET_API_TOKEN = 'generate_api_token';

 public function init ()
 {
  parent::init();
  $this->on(self::GET_API_TOKEN, [$this, 'onGenerateApiToken']);
 }


 /**
  * @inheritdoc
  * 对客户端表单数据进行验证的rule
  */
 public function rules()
 {
  return [
   [['username', 'password'], 'required'],
   ['password', 'validatePassword'],
  ];
 }

 /**
  * 自定义的密码认证方法
  */
 public function validatePassword($attribute, $params)
 {
  if (!$this->hasErrors()) {
   $this->_user = $this->getUser();
   if (!$this->_user || !$this->_user->validatePassword($this->password)) {
    $this->addError($attribute, '用户名或密码错误.');
   }
  }
 }
 /**
  * @inheritdoc
  */
 public function attributeLabels()
 {
  return [
   'username' => '用户名',
   'password' => '密码',
  ];
 }
 /**
  * Logs in a user using the provided username and password.
  *
  * @return boolean whether the user is logged in successfully
  */
 public function login()
 {
  if ($this->validate()) {
   $this->trigger(self::GET_API_TOKEN);
   return $this->_user;
  } else {
   return null;
  }
 }

 /**
  * 根据用户名获取用户的认证信息
  *
  * @return User|null
  */
 protected function getUser()
 {
  if ($this->_user === null) {
   $this->_user = User::findByUsername($this->username);
  }

  return $this->_user;
 }

 /**
  * 登录校验成功后，为用户生成新的token
  * 如果token失效，则重新生成token
  */
 public function onGenerateApiToken ()
 {
  if (!User::apiTokenIsValid($this->_user->api_token)) {
   $this->_user->generateApiToken();
   $this->_user->save(false);
  }
 }
}

/**
 * 生成 api_token
 */
public function generateApiToken()
{
 $this->api_token = Yii::$app->security->generateRandomString() . '_' . time();
}

/**
 * 校验api_token是否有效
 */
public static function apiTokenIsValid($token)
{
 if (empty($token)) {
  return false;
 }

 $timestamp = (int) substr($token, strrpos($token, '_') + 1);
 $expire = Yii::$app->params['user.apiTokenExpire'];
 return $timestamp + $expire >= time();
}

<?php
return [
 // ...
 // token 有效期默认1天
 'user.apiTokenExpire' => 1*24*3600,
];

public function behaviors() 
{
 return ArrayHelper::merge (parent::behaviors(), [ 
   'authenticator' => [ 
    'class' => QueryParamAuth::className(),
    'tokenParam' => 'token',
    'optional' => [
     'login',
     'signup-test'
    ],
   ] 
 ] );
}