Question

我正在构建一个实现自定义错误处理程序的角度应用程序。

当您有一个自定义错误处理程序且http与observable一起使用且未捕获错误时，请使用catch块，如下所示

this.http.get('/doesntExist').subscribe();

custom ErrorHandler的handleError（）函数获取HttpErrorResponse对象，该对象可用于获取必要的信息并全局处理错误。但是当您使用诺言时，例如遵循

this.http.get('/doesntExist').toPromise();

代替HttpErrorResponse，将抛出一个字符串

错误：未捕获（承诺）：HttpErrorResponse：

，您实际上无法在handleError（）方法中获取错误信息。您可以在操作中Here

看到它

这是期望的行为吗？难道我做错了什么？有什么解决方法吗？请帮忙。我被困住了；

更新

控制台中字符串错误的堆栈跟踪

Error: Uncaught (in promise): HttpErrorResponse: {"headers":{"normalizedNames":[],"lazyUpdate":null},"status":200,"statusText":"OK","url":"https://angular-promise-bug.stackblitz.io/doesntExist","ok":false,"name":"HttpErrorResponse","message":"Http failure during parsing for https://angular-promise-bug.stackblitz.io/doesntExist","error":{"error":{},"text":"<!DOCTYPE html>\n<html>\n<head>\n  <link href=\"https://fonts.googleapis.com/css?family=Source+Code+Pro:400,700|Lato:400,700,900\" rel=\"stylesheet\">\n  <base href=\"/\">\n  <meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no\" />\n  <link rel=\"stylesheet\" media=\"screen\" href=\"https://c.staticblitz.com/assets/preview-8222014a50f8588c56d057621cdaf871.css\" />\n  <script src=\"https://c.staticblitz.com/assets/common-bd7eff1ca58185bf8131b.js\" crossorigin=\"anonymous\"></script>\n  <script src=\"https://c.staticblitz.com/assets/ext-fb68da629568861fd08cb.js\" crossorigin=\"anonymous\"></script>\n  <script src=\"https://c.staticblitz.com/d/webcontainer.a966dcc4085d3fff5bb.js\" crossorigin=\"anonymous\"></script>\n  <script src=\"https://c.staticblitz.com/assets/preview-3a0c9433aa42f56dbd90b.js\" crossorigin=\"anonymous\"></script>\n  <script>(function(){_preboot(\"https://l.staticblitz.com/b/v1/angular-promise-bug/f9f42b37e9b\",{p:\"stackblitz\",a:\"AIzaSyBZSvuCzbUhuRrSps-HjM5bFClLPaFF9Vg\",o:true})})()</script>\n</head>\n<body></body>\n</html>\n"}}
    at resolvePromise (angular-promise-bug.stackblitz.io/turbo_modules/zone.js@0.8.26/dist/zone.js:814)
    at eval (angular-promise-bug.stackblitz.io/turbo_modules/zone.js@0.8.26/dist/zone.js:724)
    at SafeSubscriber.eval [as _error] (angular-promise-bug.stackblitz.io/turbo_modules/rxjs@6.3.3/internal/Observable.js:99)
    at SafeSubscriber.__tryOrUnsub (angular-promise-bug.stackblitz.io/turbo_modules/rxjs@6.3.3/internal/Subscriber.js:209)
    at SafeSubscriber.error (angular-promise-bug.stackblitz.io/turbo_modules/rxjs@6.3.3/internal/Subscriber.js:160)
    at Subscriber._error (angular-promise-bug.stackblitz.io/turbo_modules/rxjs@6.3.3/internal/Subscriber.js:93)
    at Subscriber.error (angular-promise-bug.stackblitz.io/turbo_modules/rxjs@6.3.3/internal/Subscriber.js:73)
    at MapSubscriber.Subscriber._error (angular-promise-bug.stackblitz.io/turbo_modules/rxjs@6.3.3/internal/Subscriber.js:93)
    at MapSubscriber.Subscriber.error (angular-promise-bug.stackblitz.io/turbo_modules/rxjs@6.3.3/internal/Subscriber.js:73)
    at FilterSubscriber.Subscriber._error (angular-promise-bug.stackblitz.io/turbo_modules/rxjs@6.3.3/internal/Subscriber.js:93)

Answer 1

error.rejection应该在您使用HttpErrorResponse时为您带来toPromise()。我在stackblitz中测试了以下内容

  handleError(error) {
    const zone = this.injector.get(NgZone);
    console.log('Here')
    console.log(error)

    if (!(error instanceof HttpErrorResponse)) {
      error = error.rejection;
    }
    console.log(error);
    alert('Open console to see the error')
  }

Answer 2

这很奇怪，Angular在其全局错误处理程序中没有捕获承诺拒绝。您可以采用其他方法，因为最受好评的答案建议here。这是另一个技巧

withPromise() {
      this.http.get('/doesntExist')
      .toPromise()
      .then(() => {})
      .catch((error) => {
       const errorSub = throwError (error);
       errorSub.subscribe();
      });
  }

您基本上创建了一个Observable并订阅了它，然后让Angular处理错误。但是，这又是一个很长的路要走，因为您已经可以从初始Http调用中观察到这一点。

ErrorHandler：与promise一起使用时无法获取错误对象

2 个答案: