Zero to Hero Angular 18 Full Course (Part 17) – Comprehensive Tutorial

Welcome to Part 17 of our Angular 18 Full Course! In this tutorial, we will cover more advanced topics in Angular to take your skills to the next level. This tutorial will cover more complex concepts and techniques that will help you become a complete Angular developer.

1. Observables
Observables are a powerful tool in Angular for handling asynchronous data streams. Observables are used extensively in Angular for handling HTTP requests, event handling, and other asynchronous operations. Observables allow you to subscribe to a stream of data and handle it in real-time. Observables in Angular are provided by the RxJS library, which is a powerful library for handling reactive programming in JavaScript.

To use observables in Angular, you need to import the Observable class from the RxJS library and use it to create an observable stream of data. You can then subscribe to this observable stream and handle the data that is emitted by it. Observables have operators that allow you to manipulate the data stream in various ways, such as filtering, mapping, and reducing the data.

2. Routing
Routing is an important concept in Angular that allows you to navigate between different components in your application. Angular provides a powerful routing module that allows you to define routes in your application and navigate to different components based on the URL. Routing in Angular is implemented using the RouterModule class and the ActivatedRoute and Router classes.

To implement routing in your Angular application, you need to import the RouterModule class from the @angular/router module and define routes using the RouterModule.forRoot() method. You can then use the routerLink directive to navigate to different routes in your application. You can also use the ActivatedRoute service to access route parameters and query parameters in your components.

3. Lazy Loading
Lazy loading is a technique in Angular that allows you to load modules dynamically when they are needed, instead of loading all modules at once when the application starts. Lazy loading can help improve the performance of your application by reducing the initial load time and only loading the modules that are required. Lazy loading in Angular is implemented using the loadChildren property in the route configuration.

To implement lazy loading in your Angular application, you need to define lazy-loaded modules using the loadChildren property in the route configuration. When a route with a lazy-loaded module is accessed, Angular will dynamically load the module and its components. Lazy loading helps improve the performance of your application by only loading the modules that are needed at runtime.

4. Forms
Forms are an essential part of any web application, and Angular provides a powerful FormBuilder class for handling forms in your application. Angular forms can be either template-driven forms or reactive forms. Template-driven forms are created using template-driven directives in the HTML template, while reactive forms are created using the FormBuilder class in the TypeScript code.

To create a form in Angular, you need to import the FormsModule or ReactiveFormsModule module depending on the type of form you are using. You can then use the FormBuilder class to create a form group and form controls. Angular forms provide validators and error messages that allow you to validate user input and display error messages in your forms.

5. Authentication
Authentication is a crucial aspect of web applications that allows users to log in and access secure resources. Angular provides a powerful AuthenticationService class for implementing authentication in your application. Authentication in Angular is implemented using JSON Web Tokens (JWT) for securing API requests and verifying user identities.

To implement authentication in your Angular application, you need to create a login form that sends a POST request to the authentication server with the user’s credentials. The server will then generate a JWT token and send it back to the client. The client can then store the token in local storage and use it to authenticate API requests.

In this tutorial, we covered more advanced topics in Angular to help you become a complete Angular developer. We discussed observables, routing, lazy loading, forms, and authentication in Angular. These concepts are essential for building robust and efficient Angular applications. I hope this tutorial has been helpful in expanding your knowledge of Angular. Stay tuned for more tutorials on Angular and happy coding!