js ES6 Reflect All In One

js ES6 Reflect All In One

Reflect is a built-in object that provides methods for interceptable JavaScript operations.
The methods are the same as those of proxy handlers.
Reflect is not a function object, so it's not constructible.

Reflect 是一个内置对象，它为可拦截的 JavaScript 操作提供方法。
这些方法与代理处理程序的方法相同。
Reflect 不是一个函数对象，所以它是不可构造的。

Unlike most global objects, Reflect is not a constructor.
You cannot use it with a new operator or invoke the Reflect object as a function.
All properties and methods of Reflect are static (just like the Math object).

与大多数全局对象不同，Reflect 不是构造函数。
您不能将它与 new 运算符一起使用，也不能将 Reflect 对象作为函数调用。
Reflect 的所有属性和方法都是静态的（就像 Math 对象一样）。

Reflect.apply()
Reflect.construct()
Reflect.defineProperty()
Reflect.deleteProperty()
Reflect.get()
Reflect.getOwnPropertyDescriptor()
Reflect.getPrototypeOf()
Reflect.has()
Reflect.isExtensible()
Reflect.ownKeys()
Reflect.preventExtensions()
Reflect.set()
Reflect.setPrototypeOf()

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect

反射
数据拦截
依赖注入
依赖收集

Reflect vs Object

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Reflect/Comparing_Reflect_and_Object_methods

demo

const duck = {
  name: 'Maurice',
  color: 'white',
  greeting: function() {
    console.log(`Quaaaack! My name is ${this.name}`);
  }
}

Reflect.has(duck, 'color');
// true
Reflect.has(duck, 'haircut');
// false

Reflect.ownKeys(duck);
// [ "name", "color", "greeting" ]


Reflect.set(duck, 'eyes', 'black');
// returns "true" if successful
// "duck" now contains the property "eyes: 'black'"

Decorator

@decorator

// @experimentalDecorators
function first() {
  console.log("first(): factory evaluated");
  return function (target: any, propertyKey: string, descriptor: PropertyDescriptor) {
    console.log("first(): called");
  };
}

function second() {
  console.log("second(): factory evaluated");
  return function (target: any, propertyKey: string, descriptor: PropertyDescriptor) {
    console.log("second(): called");
  };
}

class ExampleClass {
  @first()
  @second()
  method() {
    console.log('666');
  }
}

var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
    return c > 3 && r && Object.defineProperty(target, key, r), r;
};
var __metadata = (this && this.__metadata) || function (k, v) {
    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
};
// @experimentalDecorators
function first() {
    console.log("first(): factory evaluated");
    return function (target, propertyKey, descriptor) {
        console.log("first(): called");
    };
}
function second() {
    console.log("second(): factory evaluated");
    return function (target, propertyKey, descriptor) {
        console.log("second(): called");
    };
}
class ExampleClass {
    method() {
        console.log('666');
    }
}
__decorate([
    first(),
    second(),
    __metadata("design:type", Function),
    __metadata("design:paramtypes", []),
    __metadata("design:returntype", void 0)
], ExampleClass.prototype, "method", null);

https://www.typescriptlang.org/docs/handbook/decorators.html

refs

---

---

©xgqfrms 2012-2020

www.cnblogs.com/xgqfrms 发布文章使用：只允许注册用户才可以访问！

原创文章，版权所有©️xgqfrms, 禁止转载 🈲️，侵权必究⚠️！

---