globals in Angular 2?

Dirk Ecker (decker)

Aug 19, 2016·1 min read

Developing an Angular 2 application I recently needed a variable in different contexts of my application.

Knowing Angular 1.x I thought about a value provider at first place, but then I imagine, that using a global variable should also do the job. And this should be easily done by creating a separate file exporting this variable.

export let adviceId = undefined;

Okay, so let`s use it:

import {adviceId} from '../globals';
adviceId = 42;

But the compiler denies. It is not possible to change an exported variable:

Invalid left-hand side of assignment expression.

My next guess was to put it into an object:

export let globals = {
  adviceId: undefined
};

And this actually works:

import {globals} from '../globals';
globals.adviceId = 42;

But is this a good idea? It is definitly not, because Angular2 has providers for that ;-)

Do you want to read about it?