Introduction

Directives are one of the most powerful features of Angular. They allow you to extend HTML with custom behavior and create reusable components. In Angular, there are three types of directives: component directives, attribute directives, and structural directives.

Tabular Comparison

Here’s a comparison table that shows the differences between the three types of directives in Angular:

	Component Directives	Attribute Directives	Structural Directives
Selector	Uses a custom element	Uses a custom attribute	Uses a custom attribute
Purpose	Creates a new component	Changes the behavior or appearance of an element	Changes the structure of the DOM
Usage	Used as standalone elements	Used with existing elements	Used with existing elements
Example	<app-component></app-component>	<div appHighlight></div>	<div *ngIf="showContent"></div>

As you can see from the table, component directives create new components, attribute directives change the behavior or appearance of an element, and structural directives change the structure of the DOM.

Text Diagram

Here’s a text diagram that shows how a component directive can be used in Angular:

+------------+   +---------------+
| Component  |   | Custom        |
| Directive  |   | Element       |
+------------+   +---------------+
      |                  |
      |                  |
+------------+           |
| HTML       |           |
+------------+           |
      |                  |
      |                  |
+------------+   +---------------+
| CSS        |   | TypeScript    |
+------------+   +---------------+

In this diagram, we have a component directive that creates a new component using a custom element. The HTML template uses the custom element to render the component, and the CSS is used to style the component. The TypeScript code defines the behavior of the component.

Complete Code Program

Here’s a complete code program that shows how a component directive can be used in Angular:

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

@Component({
  selector: 'app-component',
  template: '<p>Hello World!</p>'
})
export class AppComponent { }

In this code program, we define a component directive called AppComponent that creates a new component using a custom element called app-component. The template for the component contains a simple paragraph element that says “Hello World!”.

Conclusion

In conclusion, directives are a powerful feature of Angular that allow you to extend HTML with custom behavior and create reusable components. By using component, attribute, and structural directives, you can create dynamic and interactive web applications that provide a seamless and intuitive user experience. With Angular’s powerful directive handling features, you can create reusable and customizable components that can be used throughout your application.