[Angular 2] Share a Service Across Angular 2 Components and Modules

Services are used to share data between components. They follow a module pattern that allows you to use the data throughout your application so that your data is consistent and in sync.

Create a service.module.ts:

import { NgModule} from ‘@angular/core‘;
import {SimpleService} from ‘./simple.service‘;

@NgModule({
})
export class ServicesModule {
    static forRoot(){
        return {
            ngModule: ServicesModule,
            providers: [SimpleService]
        }
    }
}

export {
    SimpleService
}

Simple.serivce.ts:

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

@Injectable()
export class SimpleService {

    message = "Hello";

    constructor() { }

}

app.module.ts:

import { NgModule} from "@angular/core";
import {BrowserModule} from "@angular/platform-browser";
import {AppComponent} from ‘./app.component‘;
import {HomeModule} from ‘./components/home/home.module‘;
import {WidgetsModule} from ‘./components/widgets/widgets.module‘;
import {ServicesModule} from ‘./serivces/service.module‘;

@NgModule({
    imports:[BrowserModule, HomeModule, WidgetsModule, ServicesModule.forRoot()],
    declarations:[AppComponent],
    bootstrap:[AppComponent]
})
export class AppModule{}

Use the SimpleService:

import { Component, OnInit } from ‘@angular/core‘;
import {SimpleService} from ‘../../serivces/service.module‘;

@Component({
    moduleId: module.id,
    selector: ‘home‘,
    templateUrl: ‘home.component.html‘
})
export class HomeComponent implements OnInit {

    constructor(private simpleService: SimpleService) {
        console.log("message:", simpleService.message);
    }

    ngOnInit() { }

}