Generating an instance of an enum using a string in Typescript

Question

Generating an instance of an enum using a string in Typescript

Having trouble accessing the enum members of a numeric enum in TypeScript using window[name]. The result is an undefined object.

export enum MyEnum {    
  MemberOne = 0,   
  MemberTwo = 1
}

export class ObjectUtils {
  public static GetEnumMembers(name: string): Array<string> {
    let enumInstance = window[name];

    return Object.keys(enumInstance).map((k: any) => enumInstance[k]).filter((x: any) => typeof (x) == "string");
  }
}

When trying to call the GetEnumMembers method:

ObjectUtils.GetEnumMembers("MyEnum");

The enumInstance returns as undefined.

edit: Seeking to retrieve a string array with ["MemberOne", "MemberTwo"]

javascript typescript enums

Answer 1

Answer №1

When exporting members, they will not automatically be added to the window object unless you do so manually. A better approach would be to refactor your code to accept the enum itself rather than just the enum name:

export enum MyEnum {    
  MemberOne = 0,   
  MemberTwo = 1
}

// Another file
import { MyEnum } from "./MyEnum"

class ObjectUtils {
  public static GetEnumMembers(e: {
    [key: string]: any
  }): Array<string> {
    return Object.keys(e).map((k: any) => e[k]).filter((x: any) => typeof (x) == "string");
  }
}

// Example of usage:
console.log(ObjectUtils.GetEnumMembers(MyEnum));

Answer 2

When exporting members, they will not automatically be added to the window object unless you do so manually. A better approach would be to refactor your code to accept the enum itself rather than just the enum name:

export enum MyEnum {    
  MemberOne = 0,   
  MemberTwo = 1
}

// Another file
import { MyEnum } from "./MyEnum"

class ObjectUtils {
  public static GetEnumMembers(e: {
    [key: string]: any
  }): Array<string> {
    return Object.keys(e).map((k: any) => e[k]).filter((x: any) => typeof (x) == "string");
  }
}

// Example of usage:
console.log(ObjectUtils.GetEnumMembers(MyEnum));

Generating an instance of an enum using a string in Typescript

Answer №1

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