Angular2 and TypeScript enums - dos and don'ts - enums

Question

I have a bunch of enums in my Angular2 app and for each enum I've created a corresponding utils class that provides some additional functionality. This simply goes around the TypeScript limitation that I can't add functions to an enum the same way I can do it in Java.
Here's an example of my country enum and the corresponding utils class:
import {Injectable} from "#angular/core";
export enum Country {
ANDORRA = <any>"ANDORRA",
UNITED_ARAB_EMIRATES = <any>"UNITED_ARAB_EMIRATES",
AFGHANISTAN = <any>"AFGHANISTAN",
// ...
// more countries skipped for brevity
// ...
ZAMBIA = <any>"ZAMBIA",
ZIMBABWE = <any>"ZIMBABWE"
}
#Injectable()
export class CountryUtils {
private _emptyEntry: Array<string> = ["", "", ""];
private countryData: any = {
ANDORRA: ["Andorra", "AD", "AND"],
UNITED_ARAB_EMIRATES: ["United Arab Emirates", "AE", "ARE"],
AFGHANISTAN: ["Afghanistan", "AF", "AFG"],
// ...
// more countries skipped for brevity
// ...
ZAMBIA: ["Zambia", "ZM", "ZMB"],
ZIMBABWE: ["Zimbabwe", "ZW", "ZWE"]
}
getData(country: Country): any {
if (!country) {
return this._emptyEntry;
}
return this.countryData[Country[country]];
}
getName(country: Country): any {
return this.getData(country)[0];
}
getCode2(country: Country): any {
return this.getData(country)[1];
}
getCode3(country: Country): any {
return this.getData(country)[2];
}
}
Now, as you can see I've marked the utils class as Injectable so that I can use it with DI where I need it.
The problem I'm facing is that these enums are also used in my core TS/JS model classes that are not Angular2 dependent so I can't use DI to inject an instance of my utils classes (like the one above) inside the core model classes.
The only work around that I see is to drop the Injectable() approach and to mark the methods in the utils classes as static. So this way I can just import each utils class together with the enum and use it anywhere I want.
My question is, how bad of a design decision would that be? Is it acceptable to do something like this in Angular2 or is using statics a complete no-no? I can't see anything particularly harmful other that it's like an eye sore compared to the regular DI approach.
Any advice would be very much appreciated. Thanks in advance!

Answer 1

I don't see a static class as a problem. Also, you can use Declaration Merging to add your util functionality to your enum. No need of extra class. Check below.
enum Country {
ANDORRA = <any>"ANDORRA",
UNITED_ARAB_EMIRATES = <any>"UNITED_ARAB_EMIRATES",
AFGHANISTAN = <any>"AFGHANISTAN",
// ...
// more countries skipped for brevity
// ...
ZAMBIA = <any>"ZAMBIA",
ZIMBABWE = <any>"ZIMBABWE"
}
namespace Country {
const _emptyEntry: Array<string> = ["", "", ""];
const countryData: any = {
ANDORRA: ["Andorra", "AD", "AND"],
UNITED_ARAB_EMIRATES: ["United Arab Emirates", "AE", "ARE"],
AFGHANISTAN: ["Afghanistan", "AF", "AFG"],
// ...
// more countries skipped for brevity
// ...
ZAMBIA: ["Zambia", "ZM", "ZMB"],
ZIMBABWE: ["Zimbabwe", "ZW", "ZWE"]
};
export function getData(country: Country): any {
if (!country) {
return this._emptyEntry;
}
return this.countryData[Country[country]];
}
export function getName(country: Country): any {
return this.getData(country)[0];
}
export function getCode2(country: Country): any {
return this.getData(country)[1];
}
export function getCode3(country: Country): any {
return this.getData(country)[2];
}
}
Country.getCode2(Country.AFGHANISTAN);