从响应中仅提取所需的变量 - Angular 7

Question

I have the following interface

interface Employee{name?:string;id?:string;role?:string;}

I Have a Response like this

{
   "name": "John",
   "id": "ID77777",
   "role": "Engineer",
   "bloodType": "O+ve",
   "placeOfDeployment": "NY"
}

I want to extract only the member variables of Interface.So after i am done with the mapping i should get

{
   "name": "John",
   "id": "ID77777",
   "role": "Engineer"
}

Answer 1

You can use lodash which has pick function or here's vanilla js with same result.

const res = {"name": "John","id": "ID77777","role": "Engineer","bloodType": "O+ve","placeOfDeployment": "NY"};

const user = ["name", "id", "role"].reduce((acc, key) => {
  acc[key] = res[key];
  return acc;
}, {})

Note: handle case where res has missing keys.

Answer 2

You can use object destructing

 const response = { "name": "John", "id": "ID77777", "role": "Engineer", "bloodType": "O+ve", "placeOfDeployment": "NY" } // this will extract name,id,role property from response const {name,id,role} = response; // create a new object and assign those properties let obj = { name, id, role }; console.log(obj)

Answer 3

You can use ts-transformer-keys , which enables you to obtain keys of given type.

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

const keysOfEmployee = keys<Employee>();
const response = {
  "name": "John",
  "id": "ID77777",
  "role": "Engineer",
  "bloodType": "O+ve",
  "placeOfDeployment": "NY"
};

const result = {};
keysOfEmployee.forEach(k => result[k] = response[k]);