Question

下面我尝试为401错误添加一些Angular2通用http错误处理，这些错误应该重新提示登录详细信息，然后再次重试http请求。

问题是重试不起作用，因为函数将在登录完成之前退出。我需要一种将两个或多个可观察量链在一起的方法。

我可以使用Typescripts async / await看到一种可能的方法，但我确定必须有一个RX样式的修复程序吗？

request(url: string, options?: RequestOptionsArgs, retry: boolean = true): Observable<Response> {
    return this.http.request(url, options) 
        .catch(initialError => {

            console.log(initialError);
            if (initialError.status === 401) {
                // load login screen, and re-auth
                let login = new LoginDetails();
                login.username = 'John';
                login.password = 'John';
                // this will call another observable to load a dialog form and get the credentials

                this.apiAccountLoginPost(login)
                    .subscribe(data => {
                        // save session data
                        localStorage.setItem('session', data.toJSON());
                        // retry the http request again
                        return this.request(url, options); // need to promote this
                    }, error => {
                        // process error
                        return Observable.throw(initialError);
                    });
                // TODO need to return the login retry as a Observable<Response>

Answer 1

Observable.combineLatest(someObservable, anotherObservable).subscribe(response => {
    console.log("this is array of responses: on 0 place you got response from 'someObservable, on 1 from 'anotherObservable'");
    console.log(response);
});

但在你的情况下并非如此。你能做的就是：

private sendRequest(type: RequestType, url: string, optional?: RequestOptionsArgs, body?: any):Observable<Response> {
return Observable.create((subscriber: any) => {
  someRequest.subscribe(val => {
      console.log("correct one");
      subscriber.next("push something");
  }, (err) => {
      console.log("error handling");
      subscriber.next("push some error");
  });
});
}

Answer 2

我认为你应该这样做with rxjs/add/operator/retryWhen或retry

您可以使用next或error方法来控制观察者。

see more Reactive programming, HTTP and Angular 2

如何链接多个RX observable并作为单个函数返回

2 个答案: