方法以角度返回 HttpStatusCode

Question

I want to make a method that only makes another request when the before request return StatusCode 200. I'm using angular 15.

My home.component.ts look like this and I want to todasGuias() only make another request at a time.

    todasGuias() {
    this.page= 1;
    while (this.page <= this.listaGuias.TotalPages) {
      this.homeService.getGuias( this.year, this.month, this.glosadas, this.page)
      .subscribe((data)=>{
        this.listaGuias = data.Dados[0]
        console.log(this.listaGuias.ResultList);
      })
      this.page++;
    }
  }

and my home.service.ts look like this:

 public getGuias( year: any, month: any, glosadas: any, page:any): Observable<any> {
    const token = this.token.retornaToken();
    const headers = new HttpHeaders({ Authorization: `Bearer ${token}` });

    return this.http.get(API/list?TpoRelatorio=1
    &SomenteGlosadas=${glosadas}
    &Ano=${year}
    &Mes=${month}
    &Page=${page}
    &Count=0`,{ headers }
    )
  }

any help?

Answer 1

You want to use the rxjs operator switchMap to achieve this:

todasGuias() {
    range(1, this.listaGuias.TotalPages).pipe(
       switchMap(page => this.homeService.getGuias( this.year, this.month, this.glosadas, page))
    ).subscribe((data)=>{
        this.listaGuias = data.Dados[0]
        console.log(this.listaGuias.ResultList);
      })
    }
  }

This assumes you know the total number of pages beforehand. range generates an Observable with every number from 1 to TotalPages. switchMap then maps each number to an Observable executing the http request. As switchMap only retains one subscription internally all the requests are made sequentially. If one request fails, the Observable will also fail.