Angular 2 vs Angular CLI: What are the differences?

Introduction

Angular 2 and Angular CLI are both widely used frameworks for developing web applications. While Angular 2 is a complete platform for building single-page applications, Angular CLI is a command-line interface tool that simplifies the process of creating and managing Angular projects. Although they are closely related, there are several key differences between Angular 2 and Angular CLI that developers should be aware of.

1. Template Structure:

In Angular 2, the template structure follows a component-based approach, where each component has its own HTML, CSS, and TypeScript files. This allows for better organization and separation of concerns. On the other hand, Angular CLI provides a project structure that includes separate folders for components, services, and other modules, making it easier to manage larger projects.

2. Code Generation:

Angular 2 requires developers to manually create the skeleton code for components, services, and other modules. This can be time-consuming and error-prone, especially for larger projects. Angular CLI, on the other hand, provides a set of powerful commands that automatically generate the necessary files and code for different project components, saving developers a significant amount of time and effort.

3. Build and Compilation:

Angular 2 uses a custom build process that involves transpiling TypeScript code to JavaScript, bundling all the dependencies, and generating the final output files. While this provides a high level of customization, it can be complex and requires additional tools and configuration. In contrast, Angular CLI abstracts away the build process and automates it, making it easier for developers to build, compile, and optimize their applications.

4. Testing and Debugging:

Angular 2 provides a testing framework, known as @angular/testing, which allows developers to write unit tests and perform end-to-end testing. However, setting up and configuring the testing environment can be challenging and time-consuming. Angular CLI simplifies this process by providing a built-in testing framework, making it easier for developers to write and execute tests, as well as debug their applications.

5. Project Configuration:

Angular 2 requires developers to manually configure various aspects of the project, such as routing, TypeScript compilation options, CSS preprocessors, and more. This can be overwhelming, especially for beginners. Angular CLI, on the other hand, provides a centralized configuration file (angular.json) that allows developers to easily configure different aspects of their project, reducing complexity and making it easier to maintain and update the project configuration.

6. Deployment and Optimization:

Deploying and optimizing an Angular 2 application can be a complex process, involving tasks such as minification, code splitting, tree shaking, and caching. Angular CLI simplifies this process by providing built-in optimization features, such as production builds that automatically minify and optimize the code, making the application smaller and faster to load. Additionally, Angular CLI includes features like lazy loading, which further enhances the performance of the application.

In Summary, Angular 2 and Angular CLI have several key differences. Angular 2 focuses on providing a platform for building single-page applications, while Angular CLI simplifies the development process by automating tasks like project setup, code generation, testing, and deployment. Angular CLI provides a centralized configuration file, built-in optimization features, and a modular project structure, making it easier for developers to manage and maintain their applications.