Angular 2 - 仅在未捕获错误时才执行全局错误处理程序答案

【问题标题】：Angular 2 - Global Error handler getting executed only when the error is NOT catchedAngular 2 - 仅在未捕获错误时才执行全局错误处理程序
【发布时间】：2019-03-15 03:02:11
【问题描述】：

在我的 Angular 应用程序中，有一个全局错误处理程序和一个服务负责进行 http 调用，返回类型为 Observable<any>。有些服务已明确处理错误，有些则没有。

对于那些没有被捕获的，全局错误（具有类'CustomErrorHandler'）运行良好。对于已优雅处理和捕获的服务调用，似乎不会触发全局错误。

我的问题：有没有办法执行全局错误处理，不管http服务调用是否被处理？

custom-error-handler.service.ts

@Injectable()
export class CustomErrorHandler implements ErrorHandler {
    constructor(private injector: Injector) { }

    handleError(error) {
        error = error || new Error('There was an unexpected error');
        const loggingService: LoggerService = this.injector.get(LoggerService);
        const location = this.injector.get(LocationStrategy);
        const message = error.message ? error.message : error.toString();
        const url = location instanceof PathLocationStrategy
        ? location.path() : '';

        // get the stack trace, lets grab the last 10 stacks only
        StackTrace.fromError(error).then(stackframes => {
            const stackString = stackframes
                .splice(0, 20)
                .map((sf) => {
                    return sf.toString();
                }).join('\n');

            // log with logging service
            loggingService.error({ message, url, stack: stackString });

        });

        throw error;
    }

}

auth.service.ts

@Injectable()
export class UserAuthService {
    login(emailAddress: string, password: string): Observable<boolean> {
        if (this.isAuthenticated()) {
        return Observable.of(true);
        }

        return Observable.create(observer => {
        this.http.get('http://someurl/login')
            .map(res => res.json())
            .subscribe(
              data => {
                observer.next(this.isAuthorized);
                observer.complete();
              }, err => {
                observer.error(err);
              }
           );
        });
    }

  }

my-component.ts

import { UserAuthService } from '../services/auth.service';

@Component({
    selector: 'my-component',
    templateUrl: './my-component.html',
    styleUrls: ['./my-component.scss']
})
export class MyComponent {
    constructor(private authService: UserAuthService) {}

    handleLogin() {
        this.authService.login(formValues.emailAddress, formValues.password)
            .subscribe(res => {
                console.log('Logged In');
            }, err => {
                console.log('Logging Failed'); 
                // Global Error DOESN'T fire here as the Error has been handled
            });
    }

    handleLoginPart2() {
        this.authService.login(formValues.emailAddress, formValues.password)
            .subscribe(res => {
                console.log('Logged In');
            }); // Global Error does fire here as the Error has NOT been handled
    }
}

【问题讨论】：

标签： javascript angular typescript error-handling angular2-services

【解决方案1】：

我自己解决了这个问题，方法是创建一个继承自 Http 的 HttpClient。

通过这样做，我能够优雅地处理错误。

http-client.service.ts

import { ConnectionBackend, Http, RequestOptions, RequestOptionsArgs, Response } from '@angular/http';

@Injectable()
export class HttpClient extends Http {
  http;

  constructor(backend: ConnectionBackend, defaultOptions: RequestOptions) {
    super(backend, defaultOptions);
  }

  get(url, options?: RequestOptionsArgs): Observable<Response> {
    return super.get(url, options)
      .catch(this.handleError);
  }

  private handleError(errorRes: Response | any) {
    return Observable.throw(retError);
  }
}

【讨论】：