角提供商，环状依赖关系误差

Question

我得到此错误：
提供者解析错误：无法实例化循环依赖性！

我有一个组件可以对我的后端进行HTTP调用：
Backend.component.ts

import { HttpClient } from '@angular/common/http';
public basicQuery(): void {
  this.httpClient.get('http://...')
    .subscribe(
    (response) => {
    },
    error => {
    });
}

我在每个电话中使用拦截器。
Token.interceptor.ts

public intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
  request = request.clone({
    setHeaders: {
      token: this.auth.getToken()
    }
  });
  return next
    .handle(request)
    .do(
    (response: HttpEvent<any>) => {
    },
    (error: any) => {
      return false;
  });
}

如果我有错误，我在自定义错误处理程序中处理此错误，因为我想将错误发送到后端。
custom-error handler.ts

handleError(error): void {
  this.errorLogService.logServer(error);
  super.handleError(error);
}

因此，我使用服务。
errorlog.service.ts

import { HttpClient } from '@angular/common/http';
logServer(error: Error) {
  this.httpClient.post('http://...', JSON.stringify(error.message))
    .subscribe(
    (response) => { },
    (error) => { });
}

这是问题所在，因为我也使用httpclient。但是我该如何避免这种失败，如何正确？现在我使用" http"，而不是" httpclient"。

更新1

private auth: AuthService;
constructor(
  private utils: Utils,
  private router: Router,
  private injector: Injector
) {
  this.auth = this.injector.get(AuthService);
}
public intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
  request = request.clone({
    setHeaders: {
      token: this.auth.getToken()
    }
  });
  return next
    .handle(request)
    .do(
      (response: HttpEvent<any>) => { },
      (error: any) => { return false }
    );
}

更新2

将身份服务和路由器注入身体解决问题：

public intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
  const started = Date.now();
  this.auth = this.injector.get(AuthService);
  this.router = this.injector.get(Router);
  (...)
}

Answer 1

这是您可以做到这一点的方法，不要在构造函数中注入服务，而是在函数体内进行。在这里，您也不会遇到诸如达到最大呼叫的问题。

@Injectable()
export class YourInterceptor implements HttpInterceptor {
  yourService: YourService;
  constructor(private inject: Injector) {
    //this.yourService = inject.get(YourService);
  }
  intercept(
    request: HttpRequest<any>,
    next: HttpHandler
  ): Observable<HttpEvent<any>> {
    this.yourService = this.inject.get(YourService);
    request = request.clone({
       setHeaders: {
          token: this.YourService.getToken()
       }
    });
    return next.handle(request);    
  }
}

根据您的构造函数，请尝试一下

private auth: AuthService;
private router: Router;
constructor(
  private utils: Utils,
  private injector: Injector
) {
}
public intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
  this.router = this.injector.get(Router);
  this.auth = this.injector.get(AuthService);
  request = request.clone({
    setHeaders: {
      token: this.auth.getToken()
    }
  });
  return next
    .handle(request)
    .do(
      (response: HttpEvent<any>) => { },
      (error: any) => { return false }
    );
}