Friday 16 February 2024

 What are the steps for fetching the data with Http Client & Observable Angular?053

  What are the steps for fetching the data with Http Client & Observable Angular?

Here are the steps for fetching data with HttpClient and Observables in Angular:

1. Import necessary modules:

  • In your component's module file (e.g., app.module.ts), import HttpClientModule from @angular/common/http.


import { BrowserModule } from '@angular/platform-browser';
import { HttpClientModule } from '@angular/common/http';
// ... other imports

  imports: [
    // ... other modules
  // ...
export class AppModule { }

2. Inject HttpClient in your component:

  • In your component class, inject the HttpClient service through the constructor.


import { Component, OnInit } from '@angular/core';
import { HttpClient } from '@angular/common/http';

  selector: 'app-my-component',
  templateUrl: './my-component.component.html',
  styleUrls: ['./my-component.component.css']
export class MyComponent implements OnInit {
  data: any[];

  constructor(private http: HttpClient) {}

  ngOnInit(): void {
    // Make the request here

3. Make the HTTP request:

  • Use the appropriate HTTP method (get, post, put, delete, etc.) of HttpClient to make the request to your API endpoint. The method returns an Observable.


ngOnInit(): void {
    .subscribe(data => { = data;
    }, error => {
      console.error('Error fetching data:', error);

4. Subscribe to the Observable:

  • Call the subscribe method on the Observable returned by the HTTP method. This initiates the request and provides handlers for both successful and error responses.

  • In the success callback (first argument to subscribe), handle the received data (e.g., store it in a component property).

  • In the error callback (second argument to subscribe), handle any errors that occur during the request or response.

5. Display or use the data:

  • In your component template, use the data stored in the component property to display or manipulate it as needed.

Additional considerations:

  • You can customize the http.get call with options like headers, body, etc.

  • Use RxJS operators like map, catchError, etc. to transform or handle the data stream within the subscription.

  • Remember to unsubscribe from the Observable when the component is destroyed to avoid memory leaks.

For further learning, explore the official Angular documentation and examples:

I hope this helps!




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