CODEWITHSUNDEEP
javascripttimeoutwait
Just a learner
Just a learner

Reputation: 28572

How can I add a timeout parameter to this JavaScript function?

I have the following JavaScript function. 

function ready(interval, last_wait, el, callback) {
    if (jQuery(el).length) {
        console.log("Element ready: " + el)
        setTimeout(function () {
            callback(jQuery(el));
        }, last_wait);
    } else {
        console.log("Waiting element: " + el)
        setTimeout(function () {
            ready(interval, last_wait, el, callback);
        }, interval);
    }
};

It basically waits for a DOM element to exist. If it isn't, waits more interval milliseconds. What I want is adding a timeout parameter. If the function wait timeout milliseconds in total and the DOM element still doesn't appear, then just do nothing, stop waiting and return. I can't make it work because of the recursive nature of the function. I also considered using a global variable, but it seems not the correct way to do it. Hope someone could point me in the right direction.

Upvotes: 0

Views: 193

Answers (1)

mplungjan
mplungjan

Reputation: 177796

This works for me

If you increase the stopAfter, the code will run to conclusion

var tId, stopAfter = 3
const cb = el => el.html("Callback called");
function ready(interval, last_wait, el, callback) {
  if (stopAfter === 0) {
    clearInterval(tId);
    return;
  }
  if ($(el).length) {
    clearInterval(tId);
    console.log("Element ready: " + el)
    setTimeout(function() { callback($(el)); }, last_wait);
    return;
  }
  console.log("Waiting element: " + el)
  if (!tId) tId = setInterval(function() {
    stopAfter--;
    ready(interval, last_wait, el, callback);
  }, interval);
};

// testing the above
ready(1000,2000,"#div1",cb)
setTimeout(function() {     
  $("body").append(`<div id="div1">Div1</div>`) }
,5000); 
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>

Upvotes: 1

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