jModified jQuery Plugin

Sometimes you need to know if the user has changed any of the fields on the page. I wrote a jModified jQuery plugin that will allow you to do just that. It works by hooking it up to form fields, and providing a callback method that will give you the form id, the original value, and the new value. Unlike a simple handling of the change event the original value is preserved so you can see if it actually changed.

The form fields:

<label for="a">Field A:</label>
<input id="a" name="a" type="text" value="a value" />

<br/>
<label for="b">Field B:</label>
<input id="b" name="b" type="text" value="b value" />   
    
<br/>
<label for="c">Field C:</label>
<input id="c" name="c" type="text" value="c value" />

The hookup:

<script> 
    $(function() {
        $("input").modified( { onModified: valueChanged } );
    });
    
    var isPageDirty = false;
    function valueChanged(id, previousVal, newVal) {
      isPageDirty = true;
      alert('The page is dirty.  The value for ' + id + ' has changed from ' + previousVal + " to " + newVal);
    }
  </script>

The jModified Plugin:

(function($){
 $.fn.modified = function(options) {
    
   var defaults = {  
     onModified: function(id, previousVal, newVal) { 
         alert('The value for ' + id + ' has changed from ' + previousVal + " to " + newVal ); }  
   };  
    
   var options = $.extend(defaults, options);  
  
   this.each(function() {
     $(this).data('originalValue', $(this).val());
   });
  
  return this.change(function() {
   var newValue = $(this).val();
   var originalValue = $(this).data('originalValue');
   
   if(newValue != originalValue)
     options.onModified($(this).attr("id"), originalValue, newValue);
   
  });
 };
})(jQuery);

Get the full source on GitHub.