HTTPInterceptors are great way to modify HTTP requests occurring in your application. It acts as an injectable service that can invoke when HttpRequest occurs.
HTTP Interceptor:
import { Injectable } from '@angular/core';
import { HttpInterceptor, HttpRequest, HttpHandler, HttpHeaders } from '@angular/common/http';
@Injectable()
export class CacheInterceptor implements HttpInterceptor {
intercept(req: HttpRequest<any>, next: HttpHandler) {
const httpRequest = req.clone({
headers: new HttpHeaders({
'Cache-Control': 'no-cache',
'Pragma': 'no-cache',
'Expires': 'Sat, 01 Jan 2000 00:00:00 GMT'
})
});
return next.handle(httpRequest);
}
}
Using Interceptor:
import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { FormsModule } from '@angular/forms';
import { AppComponent } from './app.component';
import { HttpClientModule, HTTP_INTERCEPTORS } from '@angular/common/http';
import { CacheInterceptor } from './http-interceptors/cache-interceptor';
@NgModule({
imports: [ BrowserModule, FormsModule ],
declarations: [ AppComponent ],
bootstrap: [ AppComponent ],
providers: [
{ provide: HTTP_INTERCEPTORS, useClass: CacheInterceptor, multi: true }
]
})
export class AppModule { }