How to wait only for 1 second when Ajax Request is made, but don't cancel the request after wait time?

Question

I have a situation where i have to return false if ajax request does not return within 1 second. But process the response after the request has been completed. Using Ajax timeout does not work for me because, it cancels the request after that time. But i want the response even if it takes long time.

Example:

function call(){
  ajax.request(...)
     if(does not respond in 1 second)
        immediately return false and wait for response
     else
        return response
}

are you using a promise Ajax library, or are you using a callback when Ajax completes? — Garrett Motzner, Jan 24 '19 at 21:48
Also, what do you mean by "return" in this context? when doing async calls, "return" doesn't really make as much sense, because a function that starts an async action returns immediately, and doesn't block waiting for that action to finish. — Garrett Motzner, Jan 24 '19 at 21:51
Check [This](https://stackoverflow.com/questions/4551175/how-to-cancel-abort-jquery-ajax-request) — NaDeR Star, Jan 24 '19 at 21:53
@RasanjanaN: the function i specified in setTimeout is only getting executed after current call stack. But i want it to be executed after 1 second not caring about other code. — JSGeek, Jan 24 '19 at 21:54

Garrett Motzner · Accepted Answer · 2019-01-24T22:17:19.247

You need to set up a race between your request finishing and your handler for the error. If the request finishes first, set a flag that you check before handling the error:

function call(){
  let finished = false;
  function callback(){ 
    finished = true 
    // your callback code goes here
  };
  ajax.request(..., callback) // make sure this is an async request
  function handleTimeout() {
    if (finished) return;
    // your timeout code goes here
  }
  setTimeout(handleTimeout, TIMEOUT_IN_MILLISECONDS);
}

alternatively to setting a flag, you could cancel the timeout.

Notice that your call function doesn't return anything. Instead, you essentially handle events (either or both the request completing or the timeout expiring).

Thanks. This works perfectly. The mistake i made is that i kept async:false which dint do the obvious. :) — JSGeek, Jan 24 '19 at 22:15

How to wait only for 1 second when Ajax Request is made, but don't cancel the request after wait time?

1 Answers1