Showing posts with label Angular. Show all posts
Showing posts with label Angular. Show all posts

NgZone in Angular | Angular's NgZone for Efficient Change Detection | runOutsideAngular function

 In Angular, NgZone is a service provided by the Angular framework to manage and facilitate change detection. Angular's change detection mechanism is a crucial part of its reactive architecture, where the framework monitors and updates the UI whenever the application's data model changes.

NgZone helps Angular detect changes efficiently by running certain code outside or inside of Angular's zone. The zone is a concept borrowed from Zone.js, a library used by Angular to intercept asynchronous operations like setTimeout, XMLHttpRequest, etc., and trigger Angular's change detection mechanism accordingly.

Here's how NgZone works:

  1. Inside the Zone: Code executed within Angular's zone is considered "inside" the zone. Angular automatically triggers change detection after any asynchronous operation that originates from inside the zone (e.g., events, promises, timers, etc.).

  2. Outside the Zone: Code executed outside Angular's zone is considered "outside" the zone. Angular does not automatically trigger change detection after any asynchronous operation that originates from outside the zone.

NgZone provides methods like run(), runGuarded(), and onStable() to control change detection behavior. Developers can use NgZone it to explicitly run code inside or outside Angular's zone as needed. This can be particularly useful for optimizing performance, handling third-party libraries that don't trigger Angular's change detection, or dealing with long-running tasks that could potentially block the UI.

Here's a basic example:

import { Component, NgZone } from '@angular/core';

  selector: 'app-component',
  template: `
    <button (click)="runOutsideZone()">Run outside zone</button>
export class appComponent {
  constructor(private ngZone: NgZone) {}

  runOutsideZone() {
    this.ngZone.runOutsideAngular(() => {
      setTimeout(() => {
        // This code runs outside Angular's zone
        // Angular won't automatically trigger change detection after this timeout
        console.log('Outside zone');
      }, 1000);


Angular Quiz for 5+ years of experience | Angular MCQ Quiz

Bootstrap Popup Module

Welcome to the Angular Quiz!

  1. You have 30 minutes to complete 28 questions.
  2. The passing mark is 85%, so aim to answer at least 24 questions correctly.
  3. Each question is multiple-choice with only one correct answer.
  4. You'll receive your score along with a detailed chart showing your performance.
  5. After completing the quiz, you can review all questions and their respective answers.
  6. Make sure to submit your answers within the time limit.
  7. If time is completed, you will be redirected directly to the result page.
  8. Good luck!

Test Your Skills on other Technologies 👇👇👇👇

Call chatgpt api from angular

Angular is a frontend framework that allows you to build web applications, and you can use it to make HTTP requests to external APIs, including the ChatGPT API. 

To call the ChatGPT API from Angular, you would typically use Angular's built-in HttpClient module to send HTTP requests to the API endpoint. Here's a basic example of how you might do this: 

First, make sure you have Angular CLI installed. If not, you can install it using npm:

npm install -g @angular/cli

Create a new Angular project:

ng new my-chatgpt-app

Navigate to your project directory:
cd my-chatgpt-app

Generate a new service to handle API calls:
ng generate service chatgpt

In your service file (chatgpt.service.ts), import HttpClient and inject it into your service constructor:

import { Injectable } from '@angular/core';
import { HttpClient } from '@angular/common/http';
import { Observable } from 'rxjs';

  providedIn: 'root'
export class ChatGptService {
  private apiUrl = ''; // Example API endpoint

  constructor(private http: HttpClient) { }

  getChatResponse(prompt: string): Observable<any> {
    const headers = {
      'Content-Type': 'application/json',
      'Authorization': 'Bearer YOUR_API_KEY' // Replace YOUR_API_KEY with your actual API key

    const body = {
      prompt: prompt,
      max_tokens: 150

    return<any>(this.apiUrl, body, { headers });

Replace '' with the actual URL of the ChatGPT API endpoint you want to call.
Replace 'YOUR_API_KEY' with your actual ChatGPT API key.
Now, you can use this service in your Angular components to make API calls. For example, in your component file (app.component.ts), you can inject the ChatGptService and call the getChatResponse method:
import { Component } from '@angular/core';
import { ChatGptService } from './chatgpt.service';

  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
export class AppComponent {
  constructor(private chatGptService: ChatGptService) {}

  ngOnInit() {
    this.chatGptService.getChatResponse('Hello, GPT!').subscribe(response => {

Here we are printing data to the console, you can print it in an HTML page as well.


Angular’s new output() API in Angular v17.3 with practical example | output() API in Angular v17.3

 In Angular, components often need to communicate with their parent components by emitting events or data. The traditional way to achieve this has been using the @Output decorator with EventEmitter. While it works, the new output() API (introduced in Angular version 17.3 as a developer preview) offers several advantages:

  • Simpler and Safer: It provides a more concise and less error-prone way to declare outputs.
  • Type Safety: It enforces stricter type checking, preventing potential runtime errors due to incorrect data types being emitted.
  • Consistency: It aligns with other function-based APIs like input() and model() in Angular, making your code more consistent and easier to understand

Limitation to using a traditional approach to declaring outputs or @output

The traditional approach to declaring outputs in Angular components using @Output and EventEmitter had some limitations that the new output() and outputFromObservable() APIs aim to address:

1. More Boilerplate Code:

  • The old approach required manual instantiation of an EventEmitter for each output:

@Output() someEvent =newEventEmitter();

  • This could lead to more verbose code, especially for components with multiple outputs.

2. Potential Type Safety Issues:

  • With EventEmitter, you had to manually ensure that the emitted data matched the desired type.
  • This could lead to runtime errors if you accidentally emit the wrong data type.

3. Less Consistent Style:

  • The use of EventEmitter didn't align with other function-based Angular APIs like @Input() and [(ngModel)].
  • This could make code less readable and maintainable.

How output() and outputFromObservable() address these limitations:

  • Concise Syntax: Both new APIs offer a more concise way to declare outputs, removing the need for manual EventEmitter creation.

         // New approach
2  someEvent = output();
4// Old approach
5@Output() someEvent =new EventEmitter();

  • Improved Type Safety: These APIs enforce stricter type checking, ensuring emitted values match the declared type. This helps prevent runtime errors.

  • Consistent Style: They align with other function-based APIs, making the code more consistent and easier to understand.

In summary, the new output() and outputFromObservable() APIs offer a more streamlined, type-safe, and consistent approach to declaring outputs in Angular components compared to the traditional @Output and EventEmitter.

Angular’s new output() API in 

Angular v17.3 with a practical example