在Typescript中：是否有“编译时”方法来获取TypeScript接口中定义的所有属性名称？ [英] In Typescript: Is there a 'compile-time' way to get all the property names defined in a TypeScript interface?

问题描述

我想创建一个通用的TypeScript类，用于渲染（作为HTML列表）一个实现特定TypeScript接口的对象数组。

I'd like to create a generic TypeScript class for rendering (as a HTML list) an array of objects which implement a specific TypeScript interface.

例如

class GenericListRenderer<T> {
  items: T[];

 constructor(listItems: T[], className?: string){
      this.items = listItems;
      ...
    }

    private getPropertyNames(): string[]{

    // What is the best way to access all property names defined in
    // TypeScript interface 'T' that was used in this generic?
    ...   
    }

    render(){
      var propNames: string[] = this.getPropertyNames();
      // render list with each item containing set of all 
      // key(prop name)/value pairs defined by interface 'T'  
      ...

    }
}

问：什么是获得'编译时'的最佳方法'在指定的（）TypeScript接口中定义的所有属性名列表？

Q: what would be the best way to get a 'compile-time' list of all property names defined in the specified () TypeScript interface?

与C ++模板一样，我相信TypeScript可以在编译时解析这些泛型，当TypeScript类型信息（如提供给用于实例化特定对象的通用的接口）很容易获得。

Like C++ templates, I believe that TypeScript could resolves these generics during "compile time", when TypeScript type information (like an interface supplied to the generic used to instantiate a particular object) is readily available.

由于可能提供了所有必需的类型信息，我只是好奇是否有一个TypeScript扩展/工具可用于访问此信息而不会过度运行时过滤' vanilla'Javascript对象 - 由于模糊的继承问题可能会出现问题（例如，如果运行时，泛型，Javascript（obj.hasOwnProperty（prop））用于过滤属性，则可能会过滤掉所需的TypeScript继承的接口属性。）

Since all the required type information is potentially supplied, I was just curious if there was a TypeScript extension/facility available to access this info w/o excessive runtime filtering of 'vanilla' Javascript objects -- which might be problematic due to ambiguous inheritance issues (e.g. desired TypeScript inherited interface properties may get filtered out if runtime, generic, Javascript (obj.hasOwnProperty(prop)) is used for filtering properties).

这个有用的属性内省潜力可以在编译时期间使用TypeScript的类型元数据超集来明确解析，而不是尝试在翻译的Javascript中解析此信息。这种类型的信息被丢弃了。

This useful property introspection potential could be unambiguously resolved with TypeScript's super-set of type meta-data during 'compile-time' vs trying to resolve this information in the translated Javascript, when all of this type information is discarded.

如果存在标准（TypeScript）方法，我讨厌'重新发明轮子'可能存在不完善的Javascript攻击。

I'd hate to 'reinvent-the wheel' with a potentially imperfect Javascript hack if a standard (TypeScript) approach exists.

此致：
初学者TypeScript Guy，
John

Sincerely: Beginner TypeScript Guy, John

推荐答案

这是可能的使用 https://github.com/Microsoft/TypeScript/pull/13940，可在typescript @ next中找到。

This is possible by using custom transformers introduced by https://github.com/Microsoft/TypeScript/pull/13940, which is available in typescript@next.

我的npm包， ts-transformer-keys 就是一个很好的例子。

My npm package, ts-transformer-keys, is a good example.

import { keys } from 'ts-transformer-keys';

interface Props {
  id: string;
  name: string;
  age: number;
}
const keysOfProps = keys<Props>();

console.log(keysOfProps); // ['id', 'name', 'age']

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