-1
我正在学习Typescript中的抽象类。 this
关键字在本课程的每个方法中都能很好地工作,除了handleRetry
。即使我试图在该方法的顶部尝试console.log(this.amiUrl)
,它也会爆炸并告诉我它找不到它。为什么我不能在rxjs .let()操作中使用“this”关键字?
我已经尝试删除受保护的关键字,相信我误解了它的使用。不用找了。
角4.3
打字稿2.4.1
import { HttpHeaders, HttpClient, HttpErrorResponse } from '@angular/common/http';
import { Injectable } from '@angular/core';
import { Observable } from 'rxjs/Observable';
import { ToastsManager } from 'ng2-toastr/ng2-toastr';
import { Store } from '@ngrx/store';
import * as uiActions from '../../core/store/actions/ui.actions';
import * as fromRoot from '../../core/store/reducers';
import { environment } from '../../../environments/environment';
@Injectable()
export abstract class RestService {
protected amiUrl = environment.api;
protected maxRetryAttempts = 3;
constructor (
private http: HttpClient,
private store: Store<fromRoot.State>,
private toastr: ToastsManager) { }
private get headers(): HttpHeaders {
const headers: HttpHeaders = new HttpHeaders();
headers.set('Authorization', 'Bearer ' + environment.accessToken);
return headers;
}
protected get(url: string) {
return this.http.get(this.amiUrl + url, { headers: this.headers })
.let(this.handleRetry);
}
protected post(url: string, payload: any) {
return this.http.post(this.amiUrl + url, payload, { headers: this.headers })
.let(this.handleRetry);
}
protected delete(url: string) {
return this.http.delete(this.amiUrl + url, { headers: this.headers })
.let(this.handleRetry);
}
protected handleRetry<T>(source: Observable<T>): Observable<T> {
return source.retryWhen(e =>
e.scan((errorCount, error) => {
if (errorCount >= this.maxRetryAttempts) {
this.store.dispatch(new uiActions.ClearRetryNotificationAction);
throw error;
} else {
this.store.dispatch(new uiActions.CreateRetryNotificationAction({ attempt: errorCount + 1, maxAttempts: this.maxRetryAttempts }))
return errorCount + 1;
}
}, 0)
.delay(2000))
}
protected handleError(err: HttpErrorResponse, customMessage?: string) {
this.store.dispatch(new uiActions.CreateErrorNotificationAction(customMessage));
console.log(err.error);
console.log(err.status);
console.log(err.name);
console.log(err.message);
if (!environment.production) {
this.toastr.error(customMessage);
}
return Observable.throw(err.message);
}
}
我会知道这是一个重复的问题,我想我的问题作为回调问题。我很惊讶我没有遇到过这个。 感谢您对关于类型函数属性未被继承的附加评论。这非常有用。我选择选项4! – wolfhoundjesse