Introduction to Angular for Beginners

What is Angular?

Angular is a popular framework developed by Google for building dynamic, single-page web applications (SPAs), a special in Angular web services in NY. It provides developers with tools to create interactive user interfaces, ensure high performance, and maintain scalable applications.

Core Concepts of Angular

• Components: These are the fundamental building blocks of Angular applications. Components are defined by classes that include logic and are bound to templates (HTML) to display data.
• Modules: An Angular application is composed of modules that organize components, directives, services, etc. The main module is the AppModule.
• Directives: Directives modify the behavior or appearance of elements in the DOM. Structural directives (like *ngIf and *ngFor) alter the layout of the DOM, while attribute directives change the appearance or behavior of elements.
• Services and Dependency Injection (DI): Services provide logic that can be used across different parts of the application. Dependency Injection allows easy use of these services in components and other services.
• Routing: Angular includes a built-in routing system that enables the creation of SPAs with multiple virtual pages.

How to Get Started with Angular

Installing Angular CLI

Angular CLI (Command Line Interface) simplifies the creation, development, and testing of Angular applications.

To install Angular CLI, you need Node.js and npm. Install Angular CLI using the command:

npm install -g @angular/cli

Creating a New Project

To create a new project, use the command:

ng new my-angular-app

After running this command, Angular CLI will ask a few questions (e.g., about routing and styling preferences). Answer them, and the CLI will create a new project with a basic structure.

Running the Project

To run the project, navigate to the project directory and use the command:

ng serve

This starts the development server, and your application will be available at http://localhost:4200/.

Basic Steps to Create Your First Component

Create a Component: You can create a new component using the CLI:

ng generate component my-component

This command creates a new directory with the component file, template, styles, and tests.

• Edit the Component Template and Logic: Edit the template file (HTML) and the component logic file (TypeScript) according to your requirements.
• Include the Component in the Application Template: Add your component to the main application template (app.component.html):

<app-my-component></app-my-component>

Example of a Simple Application

Let's consider a simple Angular application that displays a list of tasks.

Generate a task Component:

ng generate component task

Edit the task.component.html Template:

<div>

<h2>{{ taskName }}</h2>

<p>Status: {{ isCompleted ? 'Completed' : 'Pending' }}</p>

</div>

Edit the task.component.ts Logic:

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

@Component({

selector: 'app-task',

templateUrl: './task.component.html',

styleUrls: ['./task.component.css']

})

export class TaskComponent {

@Input() taskName: string = '';

@Input() isCompleted: boolean = false;

}

Use the task Component in the Main Application Template (app.component.html):

<app-task [taskName]="'Learn Angular'" [isCompleted]="true"></app-task>

<app-task [taskName]="'Write Documentation'" [isCompleted]="false"></app-task>

Conclusion

Angular is a powerful framework for developing modern web applications. It provides a comprehensive set of tools for creating components, organizing the application, managing data, and routing. By starting with the basic concepts, you can gradually deepen your knowledge and create complex and feature-rich applications.