HTTP拦截器使用Angular 2,4,6,7,8,9 TypeScript在失败的请求上获取状态0 [英] HTTP interceptor getting status 0 on failed request using Angular 2,4,6,7,8,9 TypeScript

问题描述

我使用Angular ^4.3.6具有以下HTTP拦截器的实现.

I have following implementation of HTTP interceptors with Angular ^4.3.6.

import {Injectable} from "@angular/core";
import {
  HttpInterceptor,
  HttpHandler,
  HttpRequest,
  HttpEvent,
  HttpResponse,
  HttpErrorResponse
} from "@angular/common/http";
import {Observable} from "rxjs/Observable";
import "rxjs/add/operator/do";

@Injectable()
export class InterceptorService implements HttpInterceptor {

  intercept(
    req: HttpRequest<any>,
    next: HttpHandler
): Observable<HttpEvent<any>> {
    return next.handle(req).do(evt => {
      console.log(evt);//this logs the success message properly
      if (evt instanceof HttpResponse) {
        //Keep going
      }
    },err => {
    console.log(err);
    //this logs the error but don't have useful info in it.
    });

}
}

在成功的http调用中，我得到了evt的以下成员，这些成员在第一个console.log上有效.

On the successful http call, I get following members of evt which are valid on the first console.log.

ok:true
status:200
statusText:"OK"
type:4 

]

但是如果失败，我在第二个console.log的err块中没有正确的状态代码，但是在ZONE.js的DEV控制台中有以下消息

But on failure I don't have proper status code from the err block on the second console.log but have following message in DEV console from ZONE.js

zone.js:2263选项 http://localhost:7001/coreRobo/neuralProcess 404(找不到)

zone.js:2263 OPTIONS http://localhost:7001/coreRobo/neuralProcess 404(Not Found)

name:"HttpErrorResponse"
ok:false
status:0
statusText:"Unknown Error" 

我不确定我在这里想念的是什么，但是我想让这种身份在明显是正在发生的事情时给我有效的密码，例如404,403或heck 500.

I am not sure what I am missing here but I wanted that status to give me something valid like 404,403 or heck 500 when it clearly is that what is happening.

我只是想要这些值，以便可以向UI显示正确的消息，并帮助客户端避免因失败而惊慌.

I just wanted those values so that I can show proper message to the UI and help client not panic on failure.

欢迎任何帮助.预先感谢.

Any help is welcomed. Thanks in advance.

推荐答案

如果您使用的是 CORS ，则应在您的计算机中选中" Access-Control-Allow-Origin "服务器配置.

If You are using CORS you should check "Access-Control-Allow-Origin" in your server configuration.

我在 nginx 服务器上解决了此问题，

I Solved this on my nginx server adding:

add_header "Access-Control-Allow-Origin" * always;

我错过了"总是"参数，该参数给我带来了与您相同的问题.

I missed the "always" parameter which caused me the same problem as yours.

在我的示例中，您应注意标题"*"的值.

You should pay attention to the value of the header "*" in my example.

该值必须包含允许的来源列表.

The value must contain the list of allowed origins.

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