How to disable caching with HttpClient get in Angular 6

How about add salt to url:

const salt = (new Date()).getTime();
return this.httpClient.get(`${url}?${salt}`, { responseType: 'text' });

Same concept is used for static resource links in html (css or js) to trick the cache. Adding dynamic salt to url causes fresh loading of target each time because url is different every time, but in fact it is the same.

/static/some-file.css?{some-random-symbols}

I used date because it guarantee me unique number without using random and so on. We can just use incrementing integer for each call as well.

The code provided above worked fine for me in case when I couldn't change server configuration.

Using meta HTML tags, Disable browser caching:-

<meta http-equiv="cache-control" content="no-cache, must-revalidate, post-check=0, pre-check=0">
<meta http-equiv="expires" content="0">
<meta http-equiv="pragma" content="no-cache">

or,

Add headers in http request as:-

headers = new Headers({
        'Cache-Control':  'no-cache, no-store, must-revalidate, post- 
                            check=0, pre-check=0',
        'Pragma': 'no-cache',
        'Expires': '0'
    });

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 { }