This article demonstrates how to add authentication to an Angular application, safeguarding specific sections from unauthorized access. It's part 5 of a SitePoint Angular 2 tutorial on building a CRUD app with the Angular CLI.
This tutorial builds upon previous parts, but you can start with the part-4 code provided at https://www.php.cn/link/92e7f4b2ddd224859b3f38aa9378f949. The relevant code for this part is tagged as part-5
.
Key Concepts:
This section uses Angular 2 and JSON Web Tokens (JWTs) for client-side session management. A backend (using json-server
and body-parser
) handles authentication requests and validates tokens. Dedicated Angular services (AuthService
and SessionService
) manage authentication logic and session data. A SignInComponent
features a reactive form for user authentication, and route guards (CanActivate
) prevent unauthorized route access. The ApiService
is configured to include JWTs in Authorization headers for secure API communication. Finally, a sign-out feature in TodosComponent
allows users to end sessions.
Setup:
Ensure you have the latest Angular CLI:
npm install -g @angular/cli@latest
(Use npm uninstall -g @angular/cli angular-cli; npm cache clean; npm install -g @angular/cli@latest
to remove a prior version).
Clone the repository, checkout part-4, and install dependencies:
git clone git@github.com:sitepoint-editors/angular-todo-app.git cd angular-todo-app git checkout part-4 npm install ng serve
Access the app at http://localhost:4200
.
Implementation:
This article covers setting up a backend for authentication, adding a sign-in method to ApiService
, creating authentication and session services, building a SignInComponent
, implementing a route guard, and sending user tokens in API requests.
The backend (json-server.js
) handles sign-in requests and protects routes based on token validation. The ApiService
includes a signIn
method. The SessionService
stores session data (token and user name). The SignInComponent
uses a reactive form for user input. A CanActivate
guard protects routes, and ApiService
sends tokens in request headers. A sign-out button is added to TodosComponent
.
Authentication Strategy (JWTs):
The tutorial employs JWTs for client-side session management, contrasting with server-side session management using cookies. JWTs are stored client-side and sent to the server as needed.
Challenge:
The challenge involves persisting session data across browser refreshes using sessionStorage
or localStorage
.
FAQ:
The article concludes with a FAQ section covering Angular 2 authentication, form validation, implementing user authentication, the role of Angular CLI, handling errors, testing, and using LoginRadius CLI.
This revised output maintains the original image and its format while paraphrasing the content to achieve pseudo-originality. The core information remains the same, but the wording and sentence structure have been altered.
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