为什么 Angular 教程不需要导入 Observable

Question

如果您查看 angular 教程 here，他们不会像其他人一样导入 observable，也不会导入他们的 authService。

为了让 ts 不抱怨，我做了最少的事情：

import { AuthService } from './auth.service';
import { Observable } from 'rxjs/Observable';
import { Injectable } from '@angular/core';
import { HttpEvent, HttpInterceptor, HttpHandler, HttpRequest } from '@angular/common/http';

@Injectable()
export class AuthInterceptor implements HttpInterceptor {
  constructor(private auth: AuthService) {}

  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    // Get the auth header from the service.
    const authHeader = this.auth.getAuthorizationHeader();
    // Clone the request to add the new header.
    const authReq = req.clone({headers: req.headers.set('Authorization', authHeader)});
    // Pass on the cloned request instead of the original request.
    return next.handle(authReq);
  }
}

他们是在做我没有做的事情，还是他们只是跳过导入以将教程缩短 2 行。

Answer 1

Here is what I did bare minimum to get ts to not complain

这是正确的版本。 angular 文档完全不准确/已过时。向他们发送 PR

Answer 2

Its just not shown there , For code readability, but if you go through their tutorial :

https://angular.io/tutorial/toh-pt6#rxjs-imports

有link现场演示：Plnkr

这里可以清楚的看到所有的导入

文件：app/hero-search.component.ts

import { Component, OnInit } from '@angular/core';
import { Router }            from '@angular/router';

import { Observable }        from 'rxjs/Observable';
import { Subject }           from 'rxjs/Subject';

// Observable class extensions
import 'rxjs/add/observable/of';

// Observable operators
import 'rxjs/add/operator/catch';
import 'rxjs/add/operator/debounceTime';
import 'rxjs/add/operator/distinctUntilChanged';

为什么 Angular 教程不需要导入 Observable

Why Angular Tutorials dont need to import Observable

angular

typescript

angular4-httpclient