Monday, 25 July 2022 17:43

10 Principles of Angular Interceptors

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Unravel the secrets of Angular Interceptors by understanding their principles. This article will cover the 10 Principles of Angular Interceptors. Learn what they are, how they work, and when you need them.

And learn how to use interceptors to make your life easier. If you have ever been confused by them, read on! You'll be glad you did!

What Are Interceptors?

If you're new to Angular, one of the best places to start is by learning more about the HTTP API. Interceptors are special classes that allow you to modify requests and responses. The HttpRequest and HttpResponse classes are immutable. This is important, because the app may retry a request several times before it finally succeeds. Otherwise, each attempt would result in a different request. Since HTTP is immutable, each request will remain the same regardless of whether the app succeeds or fails.

Angular's default interceptor handles HTTP requests. This interceptor is always the last in the execution chain, so you cannot modify the order in which the interceptors are applied. To change the order in which the interceptors are applied, you must build the capability into your interceptor. The official documentation outlines the following steps:

In a request interceptor, the function is called with a request object. It must return the config object directly or a promise containing the config. The function then processes the response and returns it to the caller. Using this pattern, you can modify the response object or log it to a third-party API. This way, you can make changes to your application and save changes without having to worry about the response.

How To Create An Interceptor?

If you are building a website or a web application, you may be wondering how to create an Angular interceptor. This Angular feature is useful for several reasons, including altering data, providing error handling, and time delay. This tool can also be used to develop custom middleware chains. To get started, use the Angular CLI to create your interceptor. After you have created your interceptor, you can use it to intercept any HTTP request.

You should first understand the difference between a minor example and a major one. An interceptor should intercept requests and process them according to the type of exceptions. For example, an interceptor should handle HTTP error code 401, which will occur if a user tries to access an API that is not authorized. The goal is to provide a user with the most appropriate response. A well-designed interceptor will capture exceptions and process them according to the type of error.

In addition to the request body, an interceptor can modify the response or the request itself. If the request is an HTTPPUT request, the interceptor will change the body of the request and cache the response. Interceptors can also cache the response, as any request passes through them. And because interceptors can change the request body, they are very useful. And while creating an interceptor, you should be aware that every request passes through it before being processed.