40 lines
949 B
TypeScript
40 lines
949 B
TypeScript
import { Injectable } from '@angular/core';
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import {
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HttpEvent,
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HttpRequest,
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HttpResponse,
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HttpInterceptor,
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HttpHandler
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} from '@angular/common/http';
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import { Observable } from 'rxjs/Observable';
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import { startWith, tap } from 'rxjs/operators';
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import 'rxjs/add/observable/of';
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import { RequestCache } from './request-cache.service';
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@Injectable()
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export class CachingInterceptor implements HttpInterceptor {
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constructor(private cache: RequestCache) { }
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intercept(req: HttpRequest<any>, next: HttpHandler) {
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const cachedResponse = this.cache.get(req);
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return cachedResponse
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? Observable.of(cachedResponse)
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: this.sendRequest(req, next);
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}
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sendRequest(
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req: HttpRequest<any>,
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next: HttpHandler
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): Observable<HttpEvent<any>> {
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return next.handle(req).pipe(
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tap(event => {
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if (event instanceof HttpResponse) {
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this.cache.put(req, event);
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}
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})
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);
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}
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}
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