In angular we need to create @Injactable service class and provide it to our project.
In theory we can import es6 module that executes as singleton service as well.
Except that this is not "the angular way", why this method is not so common?
angular way
import { Injectable } from '@angular/core';
@Injectable()
export class fo {
getFo():{
}
}
es6 way
const bla = []
const fo() => {return bla}
export {
fo
}
@Injectable() is only necessary when your service is injecting other services.
Example:
@Injectable()
export class fo {
constructor(private myOtherService: MyOtherService){}
}
Other than that you are right that it's practically the same thing for returning a const. However as you would appreciate it is good practice to add the annotation and the logic.
Source: https://angular.io/docs/ts/latest/cookbook/dependency-injection.html#!#-injectable-
Technically, the @Injectable()decorator is only required for a service class that has its own dependencies
@Injectables to get/set data and communicate between components and throughout our app that are part of our dependency injection tree.
There's a more in-depth guide on official docs on why you should use @Injectable().
Why @Injectable()?
@Injectable()marks a class as available to an injector for instantiation. Generally speaking, an injector reports an error when trying to instantiate a class that is not marked as@Injectable().
Source: https://angular.io/docs/ts/latest/guide/dependency-injection.html#!#why--injectable--
const; for this usage I suppose they it is practically the same thing sir. And of course I assumed OPs getFo() method is returning the same const as in the second example.