thinkphp5下json_encode问题

Question

1. 我在model层下建立User.php, User.php里有个方法getUserInfo来查询数据的,如下:

   public function getUser()
      {
          return $this->where('id', 8)->find();
      }

   然后在controller控制器下, 实例化该用户模型, 调用实例的getUserInfo,打印数据

   $userModel = new UserModel;
   dump($userModel->getUser());
   dump(json_encode($userModel->getUser()));

   第一个打印出来的数据如下

      object(app\index\model\User)#10 (32) {
        ["dateFormat":protected] => string(5) "Y/m/d"
        ["type":protected] => array(1) {
          ["birthday"] => string(9) "timestamp"
        }
        ["insert":protected] => array(1) {
          ["status"] => int(1)
        }
        ["connection":protected] => array(0) {
        }
        ["parent":protected] => NULL
        ["query":protected] => NULL
        ["name":protected] => string(4) "User"
        ["table":protected] => NULL
        ["class":protected] => string(20) "app\index\model\User"
        ["error":protected] => NULL
        ["validate":protected] => NULL
        ["pk":protected] => NULL
        ["field":protected] => array(0) {
        }
        ["readonly":protected] => array(0) {
        }
        ["visible":protected] => array(0) {
        }
        ["hidden":protected] => array(0) {
        }
        ["append":protected] => array(0) {
        }
        ["data":protected] => array(7) {
          ["id"] => int(8)
          ["nickname"] => string(4) "1111"
          ["name"] => string(4) "c某"
          ["password"] => string(6) "111111"
          ["create_time"] => int(0)
          ["update_time"] => int(0)
          ["status"] => int(0)
        }
        ["origin":protected] => array(7) {
          ["id"] => int(8)
          ["nickname"] => string(4) "1111"
          ["name"] => string(4) "c某"
          ["password"] => string(6) "111111"
          ["create_time"] => int(0)
          ["update_time"] => int(0)
          ["status"] => int(0)
        }
        ["relation":protected] => array(0) {
        }
        ["auto":protected] => array(0) {
        }
        ["update":protected] => array(0) {
        }
        ["autoWriteTimestamp":protected] => bool(true)
        ["createTime":protected] => string(11) "create_time"
        ["updateTime":protected] => string(11) "update_time"
        ["isUpdate":protected] => bool(true)
        ["updateWhere":protected] => array(1) {
          ["id"] => array(2) {
            [0] => string(2) "eq"
            [1] => int(8)
          }
        }
        ["failException":protected] => bool(false)
        ["useGlobalScope":protected] => bool(true)
        ["batchValidate":protected] => bool(false)
        ["resultSetType":protected] => string(5) "array"
        ["relationWrite":protected] => NULL
      }

   而调用json_encode方法打印json是这样子

      string(132) "{"id":8,"nickname":"1111","name":"c\u67d0","password":"111111","create_time":"1970\/01\/01","update_time":"1970\/01\/01","status":0}"

   我自己测试json_encode的value如果是对象,则会输出对象的公共属性, 测试代码如下:

       class TestClass
      {
          public $foo;
      
          public function __construct($foo) 
          {
              $this->foo = $foo;
          }
      
          public function __toString() {
              return $this->foo;
          }
      }
      
      $class = new TestClass('Hello');
      var_dump(json_encode($class));

   打印出则是string(15) "{"foo":"Hello"}" , 为什么thinkphp下的json_encode会打印这样的数据

Answer 1

原来在thinkphp5下的Model.php实现了JSON 序列化接口, 调用了Model.php的toArray方法,所以json_encode才会输出这样的数据出来.

实现 JsonSerializable 的类可以在 json_encode() 时定制他们的 JSON 表示

// JsonSerializable
public function jsonSerialize()
{
    return $this->toArray();
}

参考资料:
JSON 序列化接口