What is the significance of static constants?

In my TypeScript project, I'm working on creating a constants file that will provide an Opaque token object when

ServiceConstants.AUTH_SERVICE_TOKEN
is called.

I've experimented with two approaches:

Using ServiceConstants.ts as a namespace

export namespace ServiceConstants {

    export const AUTH_SERVICE_TOKEN: OpaqueToken = new OpaqueToken('AuthService');

}

Or using ServiceConstants.ts as a class

export class ServiceConstants {

    public static AUTH_SERVICE_TOKEN: OpaqueToken = new OpaqueToken('AuthService');

}

However, whenever I try to access this object, I encounter an error message:

Uncaught TypeError: Cannot read property 'AUTH_SERVICE_TOKEN' of undefined

How can I initialize the AUTH_SERVICE_TOKEN so that it can be simply accessed by calling

ServiceConstants.AUTH_SERVICE_TOKEN
, without needing to create a new object or encountering this error? Initially, I believed that using the namespace would suffice, but it appears that isn't the case.

Thank you

JT

Answer №1

In TypeScript, the approach to handling this situation is by creating ServiceConstants.ts as a plain file without defining it as a class or namespace. Here's all that needs to be in the file:

ServiceConstants.ts

export let AUTH_SERVICE_TOKEN: OpaqueToken = new OpaqueToken('AuthService');

Then, in the file where you need to use it:

somefile.ts

import {AUTH_SERVICE_TOKEN} from './ServiceConstants';

console.log(AUTH_SERVICE_TOKEN);

Hope this helps!

- Jon

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