Bootstrapping Providers

As of Angular 6, we have access to a great way to have our services globally available in our applications, while still being bundled and lazy loaded as efficiently as possible. @Provider decorators now take an additional argument, providedIn.

In almost every case, you want to use providedIn: 'root' - telling your angular application that this service should be a singleton, available all throughout your application. You don't even need to inject it into a module!

app/greeter.service.ts

import { Injectable } from "@angular/core";

@Injectable({
  providedIn: "root"
})
export class GreeterService {
  private message: string =
    "Registering Providers while Bootstrapping an Angular 2 application!";

  getMessage() {
    return this.message;
  }
}

View Example