Angular CLI Setup and Project Structure

What is Angular CLI?

Angular CLI is a powerful command-line tool that simplifies the process of creating, developing, and maintaining Angular applications. With a plethora of built-in commands, it allows developers to generate components, services, routes, and more with just a few keystrokes. By using Angular CLI, you can focus more on writing code and less on building the scaffolding manually.

Setting Up Angular CLI

Before you dive into the exciting world of Angular, ensure you have Node.js and npm (Node Package Manager) installed on your machine, as Angular CLI relies on them. Follow these steps to set everything up:

Check Node and npm Installation
Open your terminal (or command prompt) and run the following commands to verify the installation:
```
node -v
npm -v
```
Installation instructions can be found on the official Node.js website.
Install Angular CLI Globally
With npm installed, you can install Angular CLI globally by running:
```
npm install -g @angular/cli
```
The -g flag ensures that the CLI is accessible from anywhere on your machine.
Verify Angular CLI Installation
Confirm the successful installation of Angular CLI by checking its version:
```
ng version
```

Creating a New Angular Project

Once the setup is complete, you can create your first Angular project! Use the following command to scaffold a new application:


ng new my-angular-app

During this step, the CLI will prompt you to choose whether to include Angular Routing and which stylesheets you would like to use (CSS, SCSS, SASS, etc.). Make your selections and hit enter.

Navigating to Your Project Directory

Change your current directory to your newly created project:


cd my-angular-app

Starting the Development Server

You can start the development server running the command:


ng serve

The default port is 4200, and you can access your application by opening a web browser and navigating to http://localhost:4200. The development server will automatically reload your app when you have made changes to the code.

Understanding Project Structure

Once you have created your Angular project, you’ll find a well-organized directory structure. Here’s a breakdown of the main folders and files generated by Angular CLI:


my-angular-app/
├── e2e/                      # End-to-end tests
├── node_modules/            # Project dependencies
├── src/                     # Main source folder
│   ├── app/                 # Application-specific modules and components
│   ├── assets/              # Images, fonts, and other assets
│   ├── environments/         # Configuration settings for different environments
│   ├── index.html           # Main HTML file
│   ├── main.ts               # Main entry point of the application
│   ├── styles.css           # Global styles
│   └── polyfills.ts         # Compatibility Layer
├── angular.json             # Angular CLI configuration file
├── package.json             # Project dependencies and scripts
└── tsconfig.json            # TypeScript configuration

The `src/app` Directory

This is the heart of your Angular application. Here’s what you typically find:

Components: Each Angular component consists of an HTML template, a CSS file (for styling), and Typescript code. You can create them by running:
```
ng generate component componentName
```
Services: These are typically created to handle business logic and data manipulation. They can be generated using:
```
ng generate service serviceName
```
Modules: Angular applications are modular. You can create feature modules to better organize your application:
```
ng generate module moduleName
```

Environment Configuration

The src/environments folder contains environment-specific settings that allow you to specify different configurations for development and production. You can access these in your application using Angular's built-in dependency injection.

Global Styles and Index File

The styles.css file is where you can add global styles for your application, while index.html serves as the entry point for the application, loading necessary resources and linking styles.

Leveraging Angular CLI Commands

Beyond the initial setup, Angular CLI provides numerous commands to improve your workflow. Here are a few useful commands:

Generate a new component:


ng g c componentName

Generate a new service:
```
ng g s serviceName
```
Build the project for production:
```
ng build --prod
```

This command optimizes the build output for deployment.

Conclusion

The Angular CLI is a powerful ally in your Angular development journey. With a few simple commands, you can set up your project structure and start building robust applications efficiently. Embracing the CLI not only speeds up development but also enforces best practices in coding standards and structure. Happy coding!