A localization interceptor can be used to automatically include the user’s preferred language or locale in HTTP requests, ensuring that the server sends responses in the appropriate language.

import { Injectable } from '@angular/core';
import {
  HttpInterceptor,
  HttpRequest,
  HttpHandler,
} from '@angular/common/http';
import { LocaleService } from './locale.service';

@Injectable()
export class LocalizationInterceptor implements HttpInterceptor {
  constructor(private localeService: LocaleService) {}

  intercept(
    request: HttpRequest<unknown>, 
    next: HttpHandler
  ) {
    const userLocale = this.localeService.getUserLocale();
    const localizedRequest = request.clone({
      setHeaders: {
        'Accept-Language': userLocale,
      },
    });
    return next.handle(localizedRequest);
  }
}

A CSP interceptor can be used to automatically add Content Security Policy headers to outgoing HTTP requests to improve security.

import { Injectable } from '@angular/core';
import {
  HttpInterceptor,
  HttpRequest,
  HttpHandler,
} from '@angular/common/http';

@Injectable()
export class CspInterceptor implements HttpInterceptor {

  intercept(
    request: HttpRequest<any>, 
    next: HttpHandler
  ) {
    const cspHeader = "default-src 'self'; script-src 'self' 'unsafe-inline'";
    const cspRequest = request.clone({
      setHeaders: {
        'Content-Security-Policy': cspHeader,
      },
    });
    return next.handle(cspRequest);
  }
}

A compression interceptor can be used to automatically request compressed content (e.g., gzip) from the server, reducing the amount of data transferred over the network.

import { Injectable } from '@angular/core';
import {
  HttpInterceptor,
  HttpRequest,
  HttpHandler,
} from '@angular/common/http';

@Injectable()
export class CompressionInterceptor implements HttpInterceptor {
  intercept(
    request: HttpRequest<unknown>, 
    next: HttpHandler
  ) {
    const compressedRequest = request.clone({
      setHeaders: { 
        'Accept-Encoding': 'gzip, deflate' 
      },
    });
    return next.handle(compressedRequest);
  }
}