equivalent of jQuery.active for pure Javascript

Question

I want to check the active Ajax requests from a site which is not using jQuery so How can I write the equivalent of jQuery.active?

I want to check if the ajax requests finished after visiting the page.

i.e. I found window.XMLHttpRequest class but not sure how to use it. Any help appreciated.

Check http://stackoverflow.com/a/3148506/2025923. It's just a variable defined on jQuery object. — Tushar, Nov 10 '15 at 08:19
This doesn't answer the question but to clarify ... `window.XMLHttpRequest.DONE` is one of a family of read-only constants *(not quantities)*, each representing one of the possible states of an XHR instance - UNSENT:0; OPENED:1; HEADERS_RECEIVED:2; LOADING:3; DONE:4 . Not too sure where this is specified (W3C? IANA?) but it is common (IE, Chrome, Opera), probably universal. — Roamer-1888, Nov 10 '15 at 13:40
@Roamer-1888 which of the following options shows the active XHR : UNSENT:0; OPENED:1; HEADERS_RECEIVED:2; LOADING:3; DONE:4 ? — Mesut GUNES, Nov 10 '15 at 13:42
And there's no such thing as "the active XHR". There may be none, one or more than one XHR at any given point in time and each of them will be in one of those states. — Roamer-1888, Nov 10 '15 at 13:46
@Roamer-1888 updated the question. I wanna check if the ajax finishes or not after visit. — Mesut GUNES, Nov 10 '15 at 13:52
Assuming this to be a Greasemonkey scenario, [this question](http://stackoverflow.com/questions/629671/how-can-i-intercept-xmlhttprequests-from-a-greasemonkey-script) may possibly provide part of the solution. — Roamer-1888, Nov 10 '15 at 14:20

John Pollard · Answer 1 · 2017-03-30T14:46:44.503

1

I ended using this. If window.ajax_active == 4 then I know the ajax request has completed. Seems to work for me so far.

window.ajax_active = 0;

(function(open) {
  return XMLHttpRequest.prototype.open = function(method, url, async, user, pass) {
    this.addEventListener('readystatechange', (function() {
     if (this.readyState == 1) {
        window.ajax_active += 1;
     } else if (this.readyState == 4){
        window.ajax_active -= 1;
     } 
    }), false);
    return open.call(this, method, url, async, user, pass);
  };
})(XMLHttpRequest.prototype.open);

edited Mar 30 '17 at 14:46

answered Mar 28 '17 at 16:11

John Pollard

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Not sure how to use it, when I call `window.ajax_active` it gives the assigned value – Mesut GUNES Mar 29 '17 at 06:23
jQuery.active also gives the assigned value. What are you trying to do? – John Pollard Mar 29 '17 at 15:07
if we set `window.ajax_active = 0; ` it will return to 0 but `jQuery.active` returns the active ajax requests. – Mesut GUNES Mar 29 '17 at 15:28
Can you show an example of jQuery.active returning active ajax requests? – John Pollard Mar 29 '17 at 18:36
Okay, yea that returns the number of active ajax requests, not the ajax requests themselves. Ill edit the answer above now.. I didnt test it so let me know if that works for you – John Pollard Mar 30 '17 at 14:42
Does that give you want you're looking for? – John Pollard Apr 04 '17 at 18:35
`} else if (this.readyState == 4){` line gives error. How could I use this check number acitve requests? – Mesut GUNES Apr 05 '17 at 09:35

equivalent of jQuery.active for pure Javascript

1 Answers1