在基礎版本的config目錄下 web.php 或者高級版config目錄下的main.php中配置

‘components‘ =>[
    ‘request‘ => [
        ‘parsers‘ => [
            ‘application/json‘ => ‘yii\web\JsonParser‘,
        ],
    ],
],

在使用Yii::$app->request->post()時

調用yii\web\Request 中的post方法 :

 public function post($name = null
 
, $defaultValue = null)
    {
        if ($name === null) {
            return $this->getBodyParams();
        } else {
        
            return $this->getBodyParam($name, $defaultValue);
        }+6

調用yii\web\Request 中的getBodyParams方法，解析內容是判斷request組件中有沒有相關content-type類型的解析器配置，有的話通過Yii ::createObject() 根據配置創建實例，調用相關解析器實例的parse方法解析數據內容，解析的數據內容是通過file_get_contents(‘php://input‘) 獲取的:

/**
     * Returns the request parameters given in the request body.
     *
     * Request parameters are determined using the parsers configured in [[parsers]] property.
     * If no parsers are configured for the current [[contentType]] it uses the PHP function `mb_parse_str()`
     * to parse the [[rawBody|request body]].
     * @return array the request parameters given in the request body.
     * @throws \yii\base\InvalidConfigException if a registered parser does not implement the [[RequestParserInterface]].
     * @see getMethod()
     * @see getBodyParam()
     * @see setBodyParams()
     
 
*/
    public function getBodyParams()
    {
        if ($this->_bodyParams === null) {
            if (isset($_POST[$this->methodParam])) {
　　　　　　　　　　//post提交時，存在以$this->methodParam（默認是_method 名稱）命名的參數時，直接把$_POST內容賦值給$this_bodyParams，同時刪除$this->methodParam內容
                $this->_bodyParams = $_POST;
                unset($this->_bodyParams[$this->methodParam]);
                return $this->_bodyParams;
            }
　　　　　　　//獲取Content-Type　　　
            $rawContentType = $this->getContentType();
            if (($pos = strpos($rawContentType, ‘;‘)) !== false) {
                // e.g. application/json; charset=UTF-8
                $contentType = substr($rawContentType, 0, $pos);
            } else {
                $contentType = $rawContentType;
            }

            if (isset($this->parsers[$contentType])) {
　　　　　　　　　　//在request組件中存在相關$contentType類型配置時，創建該解析器，解析$this->getRawBody() 獲取的內容
　　　　　　　　　　// $this->getRawBody() 是通過 file_get_contents(‘php://input‘)獲取內容

$parser = Yii::createObject($this->parsers[$contentType]);
                if (!($parser instanceof RequestParserInterface)) {
                    throw new InvalidConfigException("The ‘$contentType‘ request parser is invalid. It must implement the yii\\web\\RequestParserInterface.");
                }
                $this->_bodyParams = $parser->parse($this->getRawBody(), $rawContentType);
            } elseif (isset($this->parsers[‘*‘])) {
                $parser = Yii::createObject($this->parsers[‘*‘]);
                if (!($parser instanceof RequestParserInterface)) {
                    throw new InvalidConfigException("The fallback request parser is invalid. It must implement the yii\\web\\RequestParserInterface.");
                }
                $this->_bodyParams = $parser->parse($this->getRawBody(), $rawContentType);
            } elseif ($this->getMethod() === ‘POST‘) {
                // PHP has already parsed the body so we have all params in $_POST
                $this->_bodyParams = $_POST;
            } else {
                $this->_bodyParams = [];
                mb_parse_str($this->getRawBody(), $this->_bodyParams);
            }
        }

        return $this->_bodyParams;
    }

yii\web\JsonParser json 解析器,是通過parse方法解析獲取的json內容,主要是通過框架裏面加強版的json_decode() 就是 yii\helpers\Json::decode($rawBody, $this->asArray) 把時間josn數據變為數組格式

 /**
     * Parses a HTTP request body.
     * @param string $rawBody the raw HTTP request body.
     * @param string $contentType the content type specified for the request body.
     * @return array parameters parsed from the request body
     * @throws BadRequestHttpException if the body contains invalid json and [[throwException]] is `true`.
     */
    public function parse($rawBody, $contentType)
    {
        try {
            $parameters = Json::decode($rawBody, $this->asArray);
            return $parameters === null ? [] : $parameters;
        } catch (InvalidParamException $e) {
            if ($this->throwException) {
                throw new BadRequestHttpException(‘Invalid JSON data in request body: ‘ . $e->getMessage());
            }
            return [];
        }
    }

Yii2 配置request組件解析 json數據