Angular HTTP Interceptor
Introduction
Hypertext Transfer Protocol (HTTP) interceptors are always in the middle of every client-server HTTP request and consecutive response. Interceptors allow users to perform a variety of operations on the request, performed by an application before it is sent to a server. Angular interceptors work by intercepting both incoming and outgoing HTTP requests (⚡ & Noro, 2022). Functions like authentication and data loading are requested by the Angular interceptor to the server. When a server replies, Angular interceptors may change the response object to a meaningful format. This article discusses the various types of Angular interceptors and their use.
HTTP Angular Interceptor
Logic on each HTTP request would be performed repeatedly without the Angular interceptors. HTTP requests and responses are read-only since interceptors can try to modify them. Angular apps have multiple interceptors that are applied in the order in which the requests are provided. For default handling of back-end server calls, Angular has a special interceptor called the HTTP backend (⚡ & Nero, 2022). This interceptor is always the last to execute. Interceptors operate consecutively as they have been configured.
Implementing Angular interceptors involves an initial setup and creating it using a Command Line Interface with the command “ng generate interceptor <name>”. A common use for interceptors is handling authentication requests. This is achieved by the custom head interceptor. Angular caching interceptors handle requests without transferring them to the next interceptor. This feature improves user experience by minimizing server access time. The logging interceptor collects data from a request or response calculates the average elapsed time. This is essential in detecting imminent bottlenecks and malformed requests. Angular apps have an error handling interceptor that elegantly deals with failed requests and error calls. User experience does not entail broken views and error lines being displayed.
Conclusion
The functionalities discussed above have simplified and improved the user experience. Handling outgoing requests and incoming requests together is a powerful feature offered by Angular apps. Angular interceptors handle requests, modify them to new mutated requests and return the requests without passing them to the consecutive interceptor. Using Angular interceptors in apps enhances user experience and security by streamlining the flow of requests and responses.
References
⚡, A., & Nora, H. (2022). Angular Interceptors to Manage HTTP Requests ⚡. Retrieved 24 March 2022, from https://dev-academy.com/how-to-use-angular-interceptors-to-manage-http-requests/
