Building Blocks of Angular

By Roshan Jha on Apr 16, 2021

Introduction

Angular is a powerful front-end framework developed by Google that enables the creation of dynamic, single-page applications (SPAs). Before diving deep into Angular development, it's crucial to understand its core architecture and how different parts work together to provide a seamless user experience.

In this blog, we will explore the fundamental building blocks of Angular that shape its architecture:

1. Modules

2. Components 

3. Templates

4. Metadata

5. Data Binding

6. Directives

7. Services and Dependency Injection

Each of these building blocks plays a crucial role in structuring an Angular application, ensuring maintainability, scalability, and efficiency.

1. Modules

In Angular, modules serve as the backbone of an application, grouping related components, directives, pipes, and services together. They help manage code organization and dependency management.

Key Features of Angular Modules:

  • Every Angular application has at least one root module, AppModule.
  • Modules can import and export components, services, and other modules.
  • They use the @NgModule decorator to define their structure.

Example:


2. Components

A component is the fundamental building block of an Angular application. It controls a section of the user interface (UI) and interacts with the application logic.

Key Features of Components:

  • Defined using the @Component decorator.
  • Contains an HTML template, CSS styles, and TypeScript logic.
  • Uses a selector to render the component within an HTML file.

Example:


3. Templates

A template defines the HTML structure of a component and includes Angular-specific syntax for dynamic rendering.

Key Features of Templates:

  • Use directives like *ngIf, *ngFor for dynamic content rendering. 
  • Bind data using interpolation ({{}}) and property/event bindings.
  • Support pipes for data transformation.

Example:


4. Metadata

Metadata is used to provide additional information about a class, helping Angular understand how to process it.

Key Features:

  • Attached using decorators like @Component, @NgModule, and @Injectable.
  • Defines component selectors, templates, styles, and providers.

Example:


5. Data Binding

Data binding is a powerful mechanism in Angular that synchronizes data between the component class and the template.

Types of Data Binding:

  1. Interpolation ({{ }}) - Binds component properties to the view.
  2. Property Binding ([property]="value") - Binds an element property to a component property.
  3. Event Binding ((event)="handler()") - Binds an event to a component method.
  4. Two-way Binding ([(ngModel)]="value") - Syncs data between input fields and component properties.

Example:


6. Directives

Directives modify the DOM by adding or changing behaviors and appearance.

Types of Directives:

  1. Component Directives - A directive with a template (e.g., @Component).

  2. Structural Directives - Modify the DOM structure (e.g., *ngIf, *ngFor).

  3. Attribute Directives - Change the behavior or style of elements (e.g., [ngClass], [ngStyle]).

Example:


7. Services and Dependency Injection

A service is a reusable class that provides data or logic to different parts of an application.

Key Features:

  • Services are injectable and share data across components.

  • Dependency Injection (DI) ensures efficient instance management.

  • Defined using @Injectable decorator.

Example:


Using a Service in a Component:


Conclusion

Understanding these building blocks of Angular is crucial for effective application development. By mastering modules, components, templates, metadata, data binding, directives, and services, you can build scalable and maintainable applications efficiently.

I hope this blog provides you with a clear understanding of Angular's architecture. Happy coding! 🚀