Notice This is a beta feature offered by Google. Also this is automatic translation, which means the results are often inacurate and/or hilarious. Enjoy.

delayed-observer.js

This is a basic delayed observer for jQuery.

Example

Here a very simple example of how you can use this script:

<input type="text" id="input-A" />
<input type="text" id="input-B" />

$(document).ready(function(){

	$('#input-A').delayedObserver(0.8,
		function(value, object) {
			$('#input-B').val(value);}});

Source code

/*
 jQuery delayed observer - 0.3
 (c) 2007 ~ Maxime Haineault (haineault@gmail.com)
 
 MIT License (http://www.opensource.org/licenses/mit-license.php)
 
 changelog
 ---------
 0.2 using closure, special thanks to Stephen Goguen & Tane Piper.
 0.3 now allow object chaining, added license
*/

(function() {
  var delayedObserverStack = [];
  var observed;
 
  function delayedObserverCallback(stackPos) {
    observed = delayedObserverStack[stackPos];
    if (observed.timer) clearTimeout(observed.timer);
   
    observed.timer = setTimeout(function(){
      observed.timer = null;
      observed.callback(observed.obj.val(), observed.obj);
    }, observed.delay * 1000);

    observed.oldVal = observed.obj.val();
  } 
 
  jQuery.fn.extend({
    delayedObserver:function(delay, callback){
      $this = $(this);
     
      delayedObserverStack.push({
        obj: $this, timer: null, delay: delay,
        oldVal: $this.val(), callback: callback
      });
       
      stackPos = delayedObserverStack.length-1;
     
      $this.keyup(function() {
        observed = delayedObserverStack[stackPos];
          if (observed.obj.val() == observed.obj.oldVal) return;
          else delayedObserverCallback(stackPos);
      });
      return this;
    }
  });
})();

Download

delayed-observer.js 0.3

I've made some code cleanup and added support for custom events (other than keyup) in 0.4, it's still untested for now. But feel free to play with and report me bugs/improvments. Thanks.

delayed-observer.js 0.4 (BETA)

Nothing has changed in the API, except that now it takes a third optional parameter to specify the event type ex: {event:'keyup'}. Should be 100% compatible with preview versions.

Source code

/*
 jQuery delayed observer - 0.4
 (c) 2007 ~ Maxime Haineault (haineault@gmail.com)
 
 MIT License (http://www.opensource.org/licenses/mit-license.php)
 
 changelog
 ---------
 0.2 using closure, special thanks to Stephen Goguen & Tane Piper.
 0.3 now allow object chaining, added license
 0.4 code cleanup, added support for other events than keyup
*/

(function() {
  var stack = [], target;
 
  function callback(pos) {
    target = stack[pos];
    if (target.timer) clearTimeout(target.timer);
   
    target.timer = setTimeout(function(){
      target.timer = null;
      target.callback(target.obj.val(), target.obj);
    }, target.delay * 1000);

    target.oldVal = target.obj.val();
  } 
 
  jQuery.fn.extend({
    delayedObserver:function(delay, callback, opt){
      $this = $(this), event = opt.event || 'keyup';
      
      stack.push({
        obj:    $this, timer: null, delay: delay,
        oldVal: $this.val(), callback: callback});
       
      pos = stack.length-1;
     
      $this.[event](function() {
        target = stack[pos];
          if (target.obj.val() == target.obj.oldVal) return;
          else callback(pos);
      });
      return this;
    }
  });
})();