Skip to main content

Angular 6 RESTful APIs POST/GET/PUT/ DELETE Calls Using HttpClient

Let’s start to create the RESTful Http POST/GET/PUT/ DELETE API Calls using the following steps.
1.      CREATE the app NgModule and import HttpClientModule with the help of '@angular/common/http'.
2.      CREATE CustomerComponent for GET, PUT, POST and DELETE CALLS
3.      CREATE CustomerService - A RESTful APIs is used HttpClient requests to GET, PUT, POST and DELETE data. All communication must be stateless and cacheable.
4.      Finally, IMPORT the Customer Service in your Customer Component and then call RESTful API methods as per your needs.

The following example -
app.module.ts –
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { HttpClientModule } from  '@angular/common/http';
import { RouterModule, Routes } from '@angular/router';

import { AppComponent } from './app.component';
import { CustomerComponent } from './customer/customer.component';

@NgModule({
  declarations: [
    AppComponent,
    CustomerComponent
  ],
  imports: [
    BrowserModule,
    HttpClientModule,
    RouterModule.forRoot([
      { path: 'customer-link', component: CustomerComponent }
    ])
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

customer.component.ts -
import { Component, OnInit } from '@angular/core';
import { HttpClient, HttpHeaders } from  '@angular/common/http';
import {CustomerService} from '../api/apiservice.service';//

@Component({
  selector: 'app-customer',
  templateUrl: './customer.component.html',
  styleUrls: ['./customer.component.css']
})

export class CustomerComponent implements OnInit {
 public postData;
 public customers;
 public baseURL ="http://localhost:55965/";
 //public customerModel;

  constructor( private _http: HttpClient, private _service: CustomerService) { }

  ngOnInit() {
    //Get Customer Load
    this._service.getCustomer(this.baseURL +"api/Values/GetCustomer")
        .subscribe(data => {
            this.customers = data;  
            //console.log(this.customers);        
      });

      //Get Cutomer model.
      // this._service.getCustomerModel(this.baseURL +"api/Values/GetCustomerData")
      //     .subscribe(data => {
      //       this.customerModel = data
      //       //console.log(this.customerModel);
      // });
}

  //Add Customer Action
  public addCustomer(){
    //Simple customer object is used for post the data using RestFul API Post Call.
    var customer = { Id:"11", name :"Anil", country: "India" }

    this._service.addCustomer(this.baseURL +"api/Values/PostEmployee", customer)
        .subscribe(data => {
          this.postData = data;
          //console.log(this.postData);
          alert(JSON.stringify(this.postData));
      });
    }
}


customer.component.html –
<p>
  Customer List
</p>
<table>
  <th>Id</th> <th>Name</th> <th> Country</th> <th>Actions</th>
  <tr *ngFor="let lst of customers; let i = index" border="1">
    <td>{{i+1}}</td><td>{{lst.name}}</td><td>{{lst.country}}</td> <td>Edit</td>
  </tr>
</table>

<br/>
<form id="addCustomerForm" name="addCustomerForm">
 Name - <input type="text"><br/>
 Contry - <input type="text"><br/>

 <button type="submit" class="btn btn-primary" (click)="addCustomer()"> Add Customer - POST REST API Call</button>
</form>

apiservice.service.ts -
import { Injectable } from '@angular/core';
import { HttpClient, HttpHeaders } from  '@angular/common/http';
import { CustomPromisify } from 'util';
import { observable } from 'rxjs';
import { catchError, map } from "rxjs/operators";

@Injectable({
  providedIn: 'root'
})
export class CustomerService {
  public httpOptions : any;

  constructor(private _http : HttpClient) {
    //Http Headers Options
    this.httpOptions = {
      headers: new HttpHeaders(
        { 'Content-Type': 'application/json; charset=utf-8',
          'BrowserToken' : 'auth_Token'})
    }
  }

  //Get Customer API CALL
  public getCustomer(baseUrl : string) {
    return this._http.get(baseUrl);
  };

  //Get Customer Model
  public getCustomerModel(baseUrl : string) {
    return this._http.get(baseUrl);
  };

  //Add Customer API call.
  public addCustomer (baseUrl : string, customer :any){
    return this._http.post(baseUrl, customer, this.httpOptions);
  }
}

apiservice.service.spec.ts –
import { TestBed, inject } from '@angular/core/testing';
import { CustomerService } from './apiservice.service';

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

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


The RESTful APIs example –
using System;
using System.Collections.Generic;
using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json;

namespace CoreAPI.Controllers
{
    [Produces("application/json")]
    [Route("api/Values")]
    public class ValuesController : Controller
    {
        // GET api/values
        [HttpGet]
        [Route("GetCustomer")]
        public IActionResult GetCustomer()
        {
            List<Customer> cust = new List<Customer>();
            cust.Add(new Customer { Id = "1", name = "Anil Bloggs1", country = "India" });
            cust.Add(new Customer { Id = "2", name = "Anil Bloggs2", country = "India" });
            cust.Add(new Customer { Id = "3", name = "Anil Bloggs3", country = "India" });
            cust.Add(new Customer { Id = "4", name = "Anil Bloggs4", country = "India" });

            return Json(cust);
        }

        [HttpGet]
        [Route("GetCustomerData")]
        public IActionResult GetCustomerData()
        {
            Customer cust = new Customer();
            cust.name = "Anil";
            return Json(cust);
        }

        // POST api/values
        [HttpPost]
        [Route("PostEmployee")]
        //public IActionResult Post([FromBody]Newtonsoft.Json.Linq.JObject customer) - Way 1
        //public IActionResult Post([FromBody]dynamic customer) - Way 2
        public IActionResult PostEmployee([FromBody]Object customer)
        {
            //if : [FromBody]Newtonsoft.Json.Linq.JObject customer - Way 1
            //var obj =  JsonConvert.DeserializeObject<Customer>(customer.ToString());

            //if [FromBody]dynamic customer - Way 2
            //var obj =  JsonConvert.DeserializeObject<Customer>(customer.ToString());

            //if [FromBody]Object customer - - Way 3
            var obj = JsonConvert.DeserializeObject<Customer>(customer.ToString());

            //TODO your business logic - insert in the database.

            return Json(obj);
        }
    }

    //Customer property class
    public class Customer
    {
        public string Id { get; set; }
        public string name { get; set; }
        public string country { get; set; }
    }
}

Let’s explore in detail – Angular 6 and Angular 7
By Anil Singh | Rating of this article (*****)

Popular posts from this blog

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 ...

How To Optimizing Database Performance: Tips and Techniques for Developers

Best Practices for Optimizing Database Performance: Tips and Techniques for Developers Navigating the labyrinth of database performance optimization can often seem like a daunting task for many professionals. Especially for database developers, mastering this critical skill has immense value, as it enhances both the efficiency and responsiveness of their applications.  Effective database performance optimization leads to faster data retrieval and smoother transactions.  A key challenge, however, lies in knowing  how to hire database developers who are well-versed in optimization techniques. The market is flooded with many professionals, but finding the right expert who understands the intricacies of database performance can be like looking for a needle in a haystack. Employers need to seek those who are not only proficient in their craft but also updated with the latest optimization practices. This guide, therefore, not only aims to provide developers with a compre...

Top 15+ Angular 17 Interview Questions Answers | For Experienced Professionals as well

G Google team released the latest version of Angular – Angular 17 on November 6, 2023, creating a significant milestone for the super fast front-end development. What Are the New Features in Angular 17? 1.       Angular 17 is the highly anticipated release for the community, bringing many new exciting features, updates, and improvements. 2.       New Syntax for Control Flow in Templates - new @if, @switch, @for, @case, @empty @end control flow syntax 3.       Deferred Loading - @defer partial template 4.       The Angular signals API 5.       Angular SSR and client hydration 6.       Automatic Migration to Build-in Control Flow 7.       Build Performance with ESBuild 8.       By default, set this newly generated component as a standalone, and now we don't have an app module file. To use (ng...

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 ...

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...