HTTP Interceptor Implement In Angular With Example

In my previous blog, I can discuss interceptors in angular first watch this blog link ——— add——-

How to Build an HTTP Interceptor
You must first construct an angular interceptor before you can use it. So, here we will help you create a service that will implement the HTTP interceptor angular interface. Here are some code snippets and examples to help you design your own interceptor.

There are three steps to set up an interceptor

1. First, create an injectable service.

   1. export class IntercepertService implements HttpInterceptor

2. Now, implement the intercept method within the above class.

   1. intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
        throw new Error('Method not implemented.');
      }

   2.   Parameters
      • req
        • • HttpRequest <any>
            •   The outgoing request object to handle.
      • next
        • • HttpHandler
            •  The next interceptor in the chain, or the backend if no interceptors remain in the chain.

   3. Returns

      • Observable<HttpEvent<any>>
        • •  An observable of the event stream.

1. Then add the class within the root module. Use the token named HTTP_INTERCEPTOR.

   1. providers:
      [
        {
           provide: HTTP_INTERCEPTORS,
           useClass: IntercepertService,
           multi: true
        }

Note :

• • Import the HttpClientModule just in your AppModule, then add the interceptors to the root application injector, to utilize the same instance of HttpInterceptors across the project. If you import HttpClientModule several times (for example, in lazy loading modules), each import produces a new copy of the HttpClientModule, which overwrites the interceptors given by the parent module.