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Angular

Angular is a popular open-source web application framework developed and maintained by Google. It allows developers to build dynamic, single-page applications (SPAs) using TypeScript, a superset of JavaScript. Angular was first released in 2010 as AngularJS and was completely rewritten and released as Angular 2 in 2016. The framework has since seen regular updates, with the latest major version being Angular 16 as of 2023.

Why Angular for the NHS?​

Angular offers several benefits that make it well-suited for NHS projects:

  • Robust and scalable: Angular's architecture allows for building large-scale applications that can handle complex healthcare data and workflows.
  • TypeScript support: The use of TypeScript enhances code quality and maintainability, crucial for long-term NHS projects.
  • Comprehensive ecosystem: Angular provides a complete toolkit for web development, including routing, forms, and HTTP client, reducing the need for third-party libraries.
  • Strong community and support: With Google's backing and a large developer community, Angular ensures long-term support and regular updates.
  • Cross-platform development: Angular can be used to create web, mobile, and desktop applications, providing flexibility for various NHS digital needs.

Getting Started with Angular​

To begin using Angular, you first need to set up your development environment.

1. Install Node.js and npm​

Angular requires Node.js and npm (Node Package Manager) to manage dependencies. Download and install the latest version of Node.js from nodejs.org. The npm package manager is included with Node.js.

2. Install Angular CLI​

The Angular Command Line Interface (CLI) is a powerful tool that helps in creating, managing, and running Angular applications. To install the Angular CLI globally on your system, open your terminal or command prompt and run the following command:

npm install -g @angular/cli

3. Create a New Angular Project​

With the Angular CLI installed, you can create a new Angular project. Replace my-nhs-app with your desired project name:

ng new my-nhs-app

4. Navigate into Your New Project Directory​

Change directory to your new project folder:

cd my-nhs-app

5. Start the Development Server​

To start the development server and run your application locally, use the following command:

ng serve

6. View Your Application​

Open your web browser and visit http://localhost:4200/ to see your new Angular application running. You should see the default Angular welcome page.

7. Add Features​

Use Angular CLI commands to generate components, services, modules, and more. For example, to generate a new component:

ng generate component my-new-component

8. Run Tests​

Angular includes testing tools out of the box. Run your unit tests with:

ng test

And end-to-end tests with:

ng e2e

9. Build for Production​

When you are ready to deploy your application, build it for production with:

ng build --prod

Core Concepts in Angular​

To effectively work with Angular, it is crucial to understand several core concepts that form the foundation of Angular applications:

Components​

Components are the basic building blocks of Angular applications. Each component consists of a TypeScript class that contains data and logic, an HTML template that defines the view, and a CSS file for styling. Components represent UI elements and are responsible for rendering the user interface, handling user interactions, and managing the state of the application.

Templates​

Templates are HTML files that define the view for components. They contain Angular-specific syntax, such as interpolation ({{}}), directives (*ngFor, *ngIf), and binding expressions, which allow dynamic rendering of data. Templates provide the structure and layout of the component's UI.

Directives​

Directives are instructions in the DOM that tell Angular how to transform the HTML. There are three types of directives: structural directives (e.g., *ngIf,*ngFor) that alter the layout by adding or removing elements, attribute directives (e.g., ngClass, ngStyle) that change the appearance or behavior of elements, and custom directives that developers can create to encapsulate reusable behavior.

Services​

Services are classes that handle data and logic, promoting reusability and separation of concerns across components. They are typically used for tasks such as fetching data from APIs, managing state, or implementing business logic. Services can be injected into components or other services using Angular's dependency injection system.

Dependency Injection​

Dependency Injection (DI) is a design pattern used for managing component dependencies. Angular's DI system allows you to inject services or other dependencies into components and services, making it easier to manage dependencies and promoting code reusability. DI helps in creating loosely coupled and testable code.

Modules​

Modules are containers for organizing related components, directives, and services. An Angular application is made up of at least one module, the root module (AppModule), which bootstraps the application. Modules help in structuring the application into cohesive blocks of functionality and can be used to lazy-load parts of the application, improving performance.

Example of Angular in Action​

  1. Healthcare Analysis Platform: A B2B healthcare company developed a platform using Angular to analyze medical data and health insurance pricing. This project helped businesses organize vast amounts of data and improve decision-making processes in healthcare.
  2. Enterprise Web Application for Servelec: A complete enterprise-level web application was rewritten in Angular for Servelec, a healthcare company in the UK. This project, called Oceano, demonstrates Angular's capability to handle large-scale healthcare applications.
  3. PayPal: Employs Angular for its online payment platform frontend.
  4. Gmail: Google's email service uses Angular for its single-page application interface.

Further Learning Resources​

  • Angular Official Documentation: The best place to learn everything about Angular.
  • Tour of Heroes Tutorial: An interactive tutorial provided by Angular that covers fundamental concepts.Further Learning Resources