Javascript 打字稿迭代接口属性
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typescript iterate interface properties
提问by Chris
I need to map interface properties to objects:
我需要将接口属性映射到对象：
interface Activity {
id: string,
title: string,
body: string,
json: Object
}
I currently do:
我目前这样做：
headers: Array<Object> = [
{ text: 'id', value: 'id' },
{ text: 'title', value: 'title' },
{ text: 'body', value: 'body' },
{ text: 'json', value: 'json' }
]
This gets very repetitive. What I would like is something like this:
这变得非常重复。我想要的是这样的：
headers: Array<Object> = Activity.keys.map(key => {
return { text: key, value: key }
})
回答by Nitzan Tomer
You can't, interfaces are only for compile time because javascript doesn't support it.
您不能，接口仅用于编译时，因为 javascript 不支持它。
What you can do is something like:
你可以做的是：
const Activity = {
id: "",
title: "",
body: "",
json: {}
}
type Activity = typeof Activity;
const headers: Array<Object> = Object.keys(Activity).map(key => {
return { text: key, value: key }
});
（操场上的代码）
回答by Vladyslav Zavalykhatko
If you are okay with having it added during a compile time and you are using TypeScript >= 2.4.1, you can try the way proposed here.
如果您可以在编译期间添加它，并且您使用的是 TypeScript >= 2.4.1，则可以尝试此处建议的方式。
Basically, you should add the ts-transformer-keys dependency, custom transformer, like a basic one and you'll be able to list the properties like this:
基本上，您应该添加ts-transformer-keys 依赖项，自定义转换器，就像基本的一样，您将能够列出如下属性：
import { keys } from 'ts-transformer-keys';
interface Props {
id: string;
name: string;
age: number;
}
const keysOfProps = keys<Props>();
console.log(keysOfProps); // ['id', 'name', 'age']
回答by qballer
if you would like to keep the interface ability you can do the following, @Nitzan Tomer is right. Interfaces are part of the type system, hence they are only relevant in compile time as they are omitted in the transpiled code.
如果您想保留界面功能，您可以执行以下操作，@Nitzan Tomer 是对的。接口是类型系统的一部分，因此它们仅在编译时相关，因为它们在转译代码中被省略。
class Activity {
public id: string = '';
public title: string = '';
public body: string = '' ;
public json: Object = {};
}
let activity = new Activity()
const headers: Array<Object> = Object.keys(Activity).map(key => {
return { text: key, value: key }
});
console.log(JSON.stringify(headers))
回答by T. Dayya
This approach might be a bit overkill, but i use it since i need JSON schemas anyway for validating the back end's response structure. Getting the keys from interfaces is just a nice side-effect of converting typescript interfaces into json schemas:
这种方法可能有点矫枉过正，但我使用它，因为无论如何我都需要 JSON 模式来验证后端的响应结构。从接口获取键只是将 typescript 接口转换为 json 模式的一个很好的副作用：
Using a typescript to json schema converter, one could get interfaces keys along with their types. The resulting json objects are large and verbose, so a parsing helper function could come in handy to recursively constructing simpler JS objects the way you want out of them. The good news is that a json schema always has the same structure, so it's easy to navigate.
使用打字稿到 json 模式转换器，可以获取接口键及其类型。生成的 json 对象又大又冗长，因此解析辅助函数可以派上用场，以您想要的方式递归构建更简单的 JS 对象。好消息是 json 模式始终具有相同的结构，因此易于导航。
