仅针对某些请求显示 Global Spinner

Question

I am using a global spinner on angular over regular HTTP calls.

加载程序拦截器

import { Injectable } from '@angular/core';
import {
  HttpResponse,
  HttpRequest,
  HttpHandler,
  HttpEvent,
  HttpInterceptor
} from '@angular/common/http';
import { Observable } from 'rxjs';
import { LoaderService } from '../services/loader.service';

@Injectable()
export class LoaderInterceptor implements HttpInterceptor {
  private requests: HttpRequest<any>[] = [];

  constructor(private loaderService: LoaderService) { }

  removeRequest(req: HttpRequest<any>) {
    const i = this.requests.indexOf(req);
    if (i >= 0) {
      this.requests.splice(i, 1);
    }
    this.loaderService.isLoading.next(this.requests.length > 0);
  }

  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {

    this.requests.push(req);

    console.log("No of requests--->" + this.requests.length);

    this.loaderService.isLoading.next(true);
    return Observable.create(observer => {
      const subscription = next.handle(req)
        .subscribe(
          event => {
            if (event instanceof HttpResponse) {
              this.removeRequest(req);
              observer.next(event);
            }
          },
          err => {
            alert('error' + err);
            this.removeRequest(req);
            observer.error(err);
          },
          () => {
            this.removeRequest(req);
            observer.complete();
          });
      // remove request from queue when cancelled
      return () => {
        this.removeRequest(req);
        subscription.unsubscribe();
      };
    });
  }
}

加载程序服务

import { Injectable } from '@angular/core';
import { BehaviorSubject } from 'rxjs';

@Injectable({
  providedIn: 'root'
})
export class LoaderService {

  public isLoading = new BehaviorSubject(false);
  constructor() { }
}

加载程序组件

import { Component, OnInit } from '@angular/core';
import { LoaderService } from '../../services/loader.service';

@Component({
  selector: 'app-my-loader',
  templateUrl: './my-loader.component.html',
  styleUrls: ['./my-loader.component.css']
})
export class MyLoaderComponent implements OnInit {

  loading: boolean;

  constructor(private loaderService: LoaderService) {

    this.loaderService.isLoading.subscribe((v) => {
      console.log(v);
      this.loading = v;
    });

  }
  ngOnInit() {
  }

}

I have some URLs that loads dynamically whenever a new notification is triggered, what I want is to avoid these specific calls from the loader to prevent the spinner from showing on these specific requests.

Answer 1

有几种方法可以避免拦截器，这取决于您选择哪种方法的要求。

您可以使用 HttpBackend 代替 HttpClient 进行 API 调用。这通过跳过你的拦截器来工作，因此它将跳过 ALL 你的拦截器，这对你来说可能有问题也可能没有问题。
您可以在您的请求中传递一个额外的参数，例如 skipLoadingInterceptor: boolean，如果它存在，您可以跳过拦截器中负责设置加载动画的逻辑。

仅针对某些请求显示 Global Spinner

Show Global Spinner for some request only

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