74 lines
2.4 KiB
TypeScript
74 lines
2.4 KiB
TypeScript
/**
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* @license
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* Copyright Google Inc. All Rights Reserved.
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*
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* Use of this source code is governed by an MIT-style license that can be
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* found in the LICENSE file at https://angular.io/license
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*/
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import {Injectable, InjectionToken} from '@angular/core';
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import {Observable} from 'rxjs';
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import {HttpHandler} from './backend';
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import {HttpRequest} from './request';
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import {HttpEvent} from './response';
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/**
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* Intercepts `HttpRequest` and handles them.
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*
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* Most interceptors will transform the outgoing request before passing it to the
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* next interceptor in the chain, by calling `next.handle(transformedReq)`.
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*
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* In rare cases, interceptors may wish to completely handle a request themselves,
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* and not delegate to the remainder of the chain. This behavior is allowed.
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*
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* @publicApi
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*/
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export interface HttpInterceptor {
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/**
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* Intercept an outgoing `HttpRequest` and optionally transform it or the
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* response.
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*
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* Typically an interceptor will transform the outgoing request before returning
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* `next.handle(transformedReq)`. An interceptor may choose to transform the
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* response event stream as well, by applying additional Rx operators on the stream
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* returned by `next.handle()`.
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*
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* More rarely, an interceptor may choose to completely handle the request itself,
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* and compose a new event stream instead of invoking `next.handle()`. This is
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* acceptable behavior, but keep in mind further interceptors will be skipped entirely.
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*
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* It is also rare but valid for an interceptor to return multiple responses on the
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* event stream for a single request.
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*/
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intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>>;
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}
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/**
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* `HttpHandler` which applies an `HttpInterceptor` to an `HttpRequest`.
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*
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*
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*/
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export class HttpInterceptorHandler implements HttpHandler {
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constructor(private next: HttpHandler, private interceptor: HttpInterceptor) {}
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handle(req: HttpRequest<any>): Observable<HttpEvent<any>> {
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return this.interceptor.intercept(req, this.next);
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}
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}
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/**
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* A multi-provider token which represents the array of `HttpInterceptor`s that
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* are registered.
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*
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* @publicApi
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*/
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export const HTTP_INTERCEPTORS = new InjectionToken<HttpInterceptor[]>('HTTP_INTERCEPTORS');
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@Injectable()
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export class NoopInterceptor implements HttpInterceptor {
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intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
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return next.handle(req);
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}
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}
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