本文实例分析了Yii2中Restful API原理。分享给大家供大家参考，具体如下：
Yii2 有个很重要的特性是对 Restful API的默认支持， 通过短短的几个配置就可以实现简单的对现有Model的RESTful API
这里通过分析rest部分源码，简单剖析下yii2 实现 restful 的原理，并通过一些定制实现 对 关联模型的RESTful api 操作。
~ 代表 extends from 的关系
| | rest/
| | |-Action.php ~ `\yii\base\Action`
| | |-Controller.php ~ `\yii\web\Controller`
| | | |-ActiveController.php ~ `rest\Controller`
| | |-Serializer.php ~ `yii\base\Component`
| | |-UrlRule.php ~ `yii\web\CompositeUrlRule`
| | |-CreateAction.php ~ `rest\Action`
| | |-DeleteAction.php ~ `rest\Action`
| | |-IndexAction.php ~ `rest\Action`
| | |-OptionsAction.php ~ `rest\Action`
| | |-UpdateAction.php ~ `rest\Action`
| | |-ViewAction.php ~ `rest\Action`
1. rest/Controller ~ \yii\web\Controller
Controller是 RESTful API 控制器类的基类
它在一个API请求的控制周期中一次实现了下面的步骤 1~5：
① 解析响应的内容格式
② 校验请求方法
③ 检验用户权限
④ 限制速度
⑤ 格式化响应数据
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use yii\filters\auth\CompositeAuth;use yii\filters\ContentNegotiator;use yii\filters\RateLimiter;use yii\web\Response;use yii\filters\VerbFilter;/** * Controller is the base class for RESTful API controller classes. * * Controller implements the following steps in a RESTful API request handling cycle * 1. Resolving response format (see [[ContentNegotiator]]); * 2. Validating request method (see [[verbs()]]). * 3. Authenticating user (see [[\yii\filters\auth\AuthInterface]]); * 4. Rate limiting (see [[RateLimiter]]); * 5. Formatting response data (see [[serializeData()]])behaviors contentNegotiator verbFilter authenticator rateLimiterafterAction serializeData Yii::createObject($this->serializer)->serialize($data)verbs []*/class Controller extends \yii\web\Controller{ public $serializer = 'yii\rest\Serializer'; public $enableCsrfValidation = false; public function behaviors() { return [ 'contentNegotiator' => [ 'class' => ContentNegotiator::className(), 'formats' => [ 'application/json' => Response::FORMAT_JSON, 'application/xml' => Response::FORMAT_XML, ], ], 'verbFilter' => [ 'class' => VerbFilter::className(), 'actions' => $this->verbs(), ], 'authenticator' => [ 'class' => CompositeAuth::className(), ], 'rateLimiter' => [ 'class' => RateLimiter::className(), ], ] } public function verbs() { return []; } public function serializeData($data) { return Yii::createObject($this->serializer)->serialize($data); } public function afterAction($action, $result) { $result = parent::afterAction($action, $result); return $this->serializeData($result); }} |
2. rest/ActiveController ~ rest/Controller
ActiveController 实现了一系列的和 ActiveRecord 互通数据的RESTful方法
ActiveRecord 的类名由 modelClass 变量指明， yii\db\ActiveRecordInterface ???
默认的， 支持下面的方法：
* - `index`: list of models
* - `view`: return the details of a model
* - `create`: create a new model
* - `update`: update an existing model
* - `delete`: delete an existing model
* - `options`: return the allowed HTTP methods
可以通过覆盖 actions() 并且 unsetting 响应的 action 来禁用这些默认的动作。
要增加一个新的动作， 覆盖 actions() 向其末尾增加一个新的 action class 或者 是一个新的 action method
注意一点，确保你同时也覆盖了 verbs() 方法来声明这个新的动作支持那些HTTP Method
也需要覆盖checkAccess() 来检查当前用户是否有权限来执行响应的某个动作。
根据上面的说明再写一遍 Controller
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class ActiveController extends Controller{ public #modelClass; public $updateScenario = Model::SCENARIO_DEFAULT; public $createScenario = Model::SCENARIO_DEFAULT; public function init() { parent::init(); if($this->modelClass == null){ throw new InvalidConfigException('The "modelClass" property must be set.'); } } public function actions() { return [ 'index' => [ 'class' => 'app\controllers\rest\IndexAction', 'modelClass' => $this->modelClass, 'checkAccess' => [$this, 'checkAccess'], ], 'view'... 'create'... 'update'... 'delete'... 'options'... ]; } protected function verbs() { return [ 'index' => ['GET', 'HEAD'], 'view' =>['GET', 'HEAD'], 'create' =>['POST'], 'update' =>['PUT', 'PATCH'], 'delete' =>['DELETE'], ]; } public function checkAccess($action, $model=null, $params = []) { }} |
下面来实现一个继承自 这个rest\ActiveController的 News 控制器：
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namespace app\controllers;use app\controllers\rest\ActiveController; #刚才这个AC，我从yii/rest下面拷贝了一份出来class NewsController extends ActiveController{ public $modelClass ='app\models\News';} |
定义到这里就足够实现 rest\ActiveController 里面的默认方法了
下面来覆盖下，实现一些定制的方法
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class NewsController extends ActiveController{ public $modelClass = 'app\models\News'; #定制serializer #public $serializer = 'yii\rest\Serializer'; public $serializer = [ 'class' => 'app\controllers\rest\Serializer', 'collectionEnvelope' => 'items', ]; public function behaviors() { $be = ArrayHelper::merge( parent::behaviors(), [ 'verbFilter' => [ 'class' => VerbFilter::className(), 'actions' => [ 'index' => ['get'], ... ] ], 'authenticator' => [ 'class' => CompositeAuth::className(), 'authMethods' => [ HttpBasicAuth::className(), HttpBearerAuth::className(), QueryParamAuth::className(), ] ], 'contentNegotiator' => [ 'class' => ContentNegotiator::className(), 'formats' => [ 'text/html' => Response::FORMAT_HTML, ] ], 'access' => [ 'class' => AccessControl::className(), 'only' => ['view'], 'rules' => [ [ 'actions' => ['view'], 'allow' => false, 'roles' => ['@'], ], ], ] ], ); return $be; } public function checkAccess() { }} |
3. 定制Actions
如果要对 Actions 进行大的改动，建议拷贝一份出来，不要使用原始的 yii\rest\XXXAction命名空间
我这里以要实现对related models进行 CURD 操作为目标进行大的改动
Action
在定制各个action之前， 先看看它们的基类 rest\Action, 主要是一个 findModel的方法
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class Action extend \yii\base\Action{ public $modelClass; public $findModel; public $checkAccess; public function init() { if($this->modelClass == null) { throw new InvalidConfigException(get_class($this). '::$modelClass must be set'); } } public function findModel($id) { if($this->findModel !== null) { return call_user_func($this->findModel, $id, $this); } $modelClass = $this->modelClass; $keys = $modelClass::primaryKey(); if(count($keys) > 1) { $values = explode(',', $id); if.. } elseif($id !== null) { $model = $modelClass::findOne($id); } if(isset($model)){ return $model; }else { throw new NotFoundHttpException("Object not found: $id"); } }} |
view
view 动作不需要改动，因为 model 有 getRelated 的自有机制
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class ViewAction extend Action{ public function run($id) { $model = $this->findModel($id); if($this->checkAccess) { call_user_func($this->checkAccess, $this->id, $model); } }} |
update
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public function run($id){ /* @var $model ActiveRecord */ $model = $this->findModel($id); if ($this->checkAccess) { call_user_func($this->checkAccess, $this->id, $model); } $model->scenario = $this->scenario; $model->load(Yii::$app->getRequest()->getBodyParams(), ''); $model->save(); return $model;} |
经过改造后，需要满足对关联模型的update动作
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public function run($id){ /* @var $model ActiveRecord */ $model = $this->findModel($id); if ($this->checkAccess) { call_user_func($this->checkAccess, $this->id, $model); } $model->scenario = $this->scenario; /* * * x-www-form-urlencoded key=>value * image mmmmmmmm * link nnnnnnnnnn * newsItem[title]=>ttttttttttt , don't use newsItem["title"] * newsItem[body]=>bbbbbbbbbbb * don't use newsItem=>array("title":"tttttt","body":"bbbbbbb") * don't use newsItem=>{"title":"ttttttt","body":"bbbbbbbb"} * */ $newsItem = Yii::$app->getRequest()->getBodyParams()['newsItem']; /* Array ( [title] => ttttttttttt [body] => bbbbbbbbbbb ) */ $model->newsItem->load($newsItem, ''); #$model->newsItem->load(Yii::$app->getRequest()->getBodyParams(), ''); #print_R($model->newsItem);exit; #print_R($model->newsItem);exit; if($model->save()) { $model->load(Yii::$app->getRequest()->getBodyParams(), ''); $model->newsItem->save(); } return $model;} |
这里还应该对 newsItem save 失败 的情况进行处理，暂且不处理。
希望本文所述对大家基于Yii框架的PHP程序设计有所帮助。
