Angular - 如何延迟 HTTP 请求

Question

I have an application that loops through an array and makes an API call for each object in the array. The issue is all of the requests are being fired at once. The delay operator is completly ignored.

 public StartIt() {

    const len = this.stocks.length;
    console.log(len);

    for (const el of this.stocks) {
      this.iex.getFiveDay(el.Symbol).subscribe((res: any) => {
        console.log(res);
        this.ops.getVolAvg(res);
        this.datax.push(res);

      });



    }
  } 



 public getFiveDay(symbol) {
    const url: any = this.getApiUrl(symbol, iexEndPointType.fiveday);
    console.log('IEX SERVICE - getFiveDay(): ' + url);
    return this.httpClient.get(url).pipe(delay(5000));
  }

Answer 1

If you just want to add fixed delay of 5s for every request, then this might help you

const all = [1,2,3,4,5];
all.forEach((each, i) => {
    setTimeout(() => {
    console.log(each); // Call your http request
  }, i * 5000)
});