使用 `属性` 装饰器修改实例变量

Question

全部，

是否可以使用property装饰器修改实例变量？

例如，

const config = [
 a: { },
 b: { },
];

class Test {
    @fetchObjectKey('a')
    public message;  // Should fetch the value against the `key` supplied & assign it to `instance` ?
   
 //...
}

Answer 1

// You get better auto completion when its casted as const
const config = <const>{
  a: { foo: 1 },
  b: { foo: 2 }
};

function fetchObjectKey(key: keyof typeof config) {
  return (target: object, propertyKey: string) => {
    Reflect.set(target, propertyKey, config[key].foo);
  };
}

// set property based on argument
class Test {
  @fetchObjectKey("a")
  public message!: number;
}

console.log(new Test().message); // will be 1

使用 `属性` 装饰器修改实例变量

Modify the instance variable using `property` decorator

javascript

typescript

typescript-decorator