jQuery plugin to detect when a user has finished typing in a field. Fires a callback function when typing is complete & has configurable timeout.

typing_finished.js

/**
 * jQuery typingFinished plugin. Fire a callback function when the user is finished typing.
 * @param timeout  The timeout in milliseconds per interval.
 * @param callback The callback function to fire when the user finishes typing.
 * @return Object
 *
 * Example:
 * $('input').typingFinished(500, function(e) {
 *   console.log('Done typing. Last key pressed: '+ e.keyCode);
 * });
 */

$.fn.typingFinished = function(timeout, callback) {
  var timer = undefined,
      self = $(this);

  self.keyup(function(e) {
    if(typeof timer == "undefined") {
      timer = setTimeout(function() {
        callback(e);
      }, timeout);
    }
  }).keydown(function(e) {
    if(typeof timer !== "undefined") {
      clearTimeout(timer);
      timer = undefined;
    }
  });

  return self;
}