Skip to main content

Angular 5 and 4 - Creating and Using Services

How To Create Angular 5 and 4 Service?
What Is an Angular Service? Angular service is a class that encapsulates some methods like GET/POST/PUT and provides it result as a service for across your application.

Stayed Informed – Angular 5 and Angular 4 Documents
Features of Service -
ü  Service class is decorated with Injectable decorator.
ü  Services are singleton objects.
ü  Services are capable of returning the data in the form promises or observables.
ü  The Injectable decorator is required only if our service class is making use of some Angular injectable like Http, Response and HttpModule service within it
ü  And so on.

Angular 5 and 4 Service example -
The following Steps -
ü  Steps 1 - Create an Angular Project
ü  Steps 2 - Create new service
ü  Steps 3 - Import the service in the app components
ü  Steps 4 - Use to Imported Service to display in app HTML page
ü  Steps 5 - Result

The Result looks like –
Create an Angular Project using the command – “ng new ServiceDemo”
 D:\Angular>ng new ServiceDemo


Create new service using the command - “ng new DateService”
D:\Angular\ServiceDemo>ng g service DateService
  create src/app/date-service.service.spec.ts (405 bytes)
  create src/app/date-service.service.ts (117 bytes)

The above create service commands created two files one for service class and other one is test services class.
ü  date-service.service.spec.ts
ü  date-service.service.ts

And code class looks like for – “date-service.service.ts
import { Injectable } from '@angular/core';

@Injectable()
export class DateServiceService {

  constructor() { }
 
  //Create a servce method to get today date.
  getTodayDate(){
     let today = new Date();

     return today;
  }
}

And code class looks like for – “date-service.service.spes.ts
import { TestBed, inject } from '@angular/core/testing';

import { DateServiceService } from './date-service.service';

describe('DateServiceService', () => {
  beforeEach(() => {
    TestBed.configureTestingModule({
      providers: [DateServiceService]
    });
  });

  it('should be created', inject([DateServiceService], (service: DateServiceService) => {
    expect(service).toBeTruthy();
  }));
});


Import the service in the app components and the use to display in the app HTML page.

The code looks like – “app.component.ts
import { Component } from '@angular/core';
import {DateServiceService} from '../app/date-service.service';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  title = 'Service App';
  todayDate;

  constructor(private dateService : DateServiceService){
    this.todayDate = dateService.getTodayDate();
  }
}

The code looks like – “app.component.html
<!--The content below is only a placeholder and can be replaced.-->
<div style="text-align:center">
  <h1>
    Welcome to {{title}}!
  </h1>
  <img width="300" alt="Angular Logo" src="img.png">
</div>

<div>
  <h2>Today Is -</h2> {{todayDate}}
</div>

You can also see the video –
I hope you are enjoying with this post! Please share with you friends. Thank you!!
By Anil Singh | Rating of this article (*****)

Popular posts from this blog

Angular 2, 4, 5, 6, 7, 8 and 9 Interview Questions and Answers -Books

» Are you preparing for Angular Interview? Buy this book (Including Angular 8, 7, 6, 5,4, 2) Interview Q/A Interview Q/A Interview Q/A Interview Q/A Interview Q/A Interview Q/A Interview Q/A » A Complete Guide Book of Angular 9 This is a concise, complete overview of the key aspects of Angular 9. It is fully up to date with the latest release of Angular. This article provide all the important aspects required for angular developers looking for brief and useful content... Posted In Angular 9 » A Complete Guide Book of Angular 8 This is a concise, complete overview of the key aspects of Angular 9. It is fully up to date with the latest release of Angular. This article provide all the important aspects required for angular developers looking for brief and useful content... Posted In Angular 8 » A Complete Guide Book of Angular 7 This is a concise, complete overview of the key aspects of Angular 7. It is fully up to date with the latest release of Angular. This

39 Best Object Oriented JavaScript Interview Questions and Answers

Most Popular 37 Key Questions for JavaScript Interviews. What is Object in JavaScript? What is the Prototype object in JavaScript and how it is used? What is "this"? What is its value? Explain why "self" is needed instead of "this". What is a Closure and why are they so useful to us? Explain how to write class methods vs. instance methods. Can you explain the difference between == and ===? Can you explain the difference between call and apply? Explain why Asynchronous code is important in JavaScript? Can you please tell me a story about JavaScript performance problems? Tell me your JavaScript Naming Convention? How do you define a class and its constructor? What is Hoisted in JavaScript? What is function overloadin

25 Best Vue.js 2 Interview Questions and Answers

What Is Vue.js? The Vue.js is a progressive JavaScript framework and used to building the interactive user interfaces and also it’s focused on the view layer only (front end). The Vue.js is easy to integrate with other libraries and others existing projects. Vue.js is very popular for Single Page Applications developments. The Vue.js is lighter, smaller in size and so faster. It also supports the MVVM ( Model-View-ViewModel ) pattern. The Vue.js is supporting to multiple Components and libraries like - ü   Tables and data grids ü   Notifications ü   Loader ü   Calendar ü   Display time, date and age ü   Progress Bar ü   Tooltip ü   Overlay ü   Icons ü   Menu ü   Charts ü   Map ü   Pdf viewer ü   And so on The Vue.js was developed by “ Evan You ”, an Ex Google software engineer. The latest version is Vue.js 2. The Vue.js 2 is very similar to Angular because Evan You was inspired by Angular and the Vue.js 2 components looks like -

nullinjectorerror no provider for httpclient angular 17

In Angular 17 where the standalone true option is set by default, the app.config.ts file is generated in src/app/ and provideHttpClient(). We can be added to the list of providers in app.config.ts Step 1:   To provide HttpClient in a standalone app we could do this in the app.config.ts file, app.config.ts: import { ApplicationConfig } from '@angular/core'; import { provideRouter } from '@angular/router'; import { routes } from './app.routes'; import { provideClientHydration } from '@angular/platform-browser'; //This (provideHttpClient) will help us to resolve the issue  import {provideHttpClient} from '@angular/common/http'; export const appConfig: ApplicationConfig = {   providers: [ provideRouter(routes),  provideClientHydration(), provideHttpClient ()      ] }; The appConfig const is used in the main.ts file, see the code, main.ts : import { bootstrapApplication } from '@angular/platform-browser'; import { appConfig } from '

List of Countries, Nationalities and their Code In Excel File

Download JSON file for this List - Click on JSON file    Countries List, Nationalities and Code Excel ID Country Country Code Nationality Person 1 UNITED KINGDOM GB British a Briton 2 ARGENTINA AR Argentinian an Argentinian 3 AUSTRALIA AU Australian an Australian 4 BAHAMAS BS Bahamian a Bahamian 5 BELGIUM BE Belgian a Belgian 6 BRAZIL BR Brazilian a Brazilian 7 CANADA CA Canadian a Canadian 8 CHINA CN Chinese a Chinese 9 COLOMBIA CO Colombian a Colombian 10 CUBA CU Cuban a Cuban 11 DOMINICAN REPUBLIC DO Dominican a Dominican 12 ECUADOR EC Ecuadorean an Ecuadorean 13 EL SALVADOR