Update script.aculo.us to 1.5_rc2, and Prototype to 1.4.0_pre7

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2386 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 238 insertions, 271 deletions

diff --git a/railties/html/javascripts/dragdrop.js b/railties/html/javascripts/dragdrop.js
index c0fd1d1e53..a8ed953a7f 100644
--- a/railties/html/javascripts/dragdrop.js
+++ b/railties/html/javascripts/dragdrop.js
@@ -2,193 +2,79 @@
 // 
 // Element.Class part Copyright (c) 2005 by Rick Olson
 // 
-// Permission is hereby granted, free of charge, to any person obtaining
-// a copy of this software and associated documentation files (the
-// "Software"), to deal in the Software without restriction, including
-// without limitation the rights to use, copy, modify, merge, publish,
-// distribute, sublicense, and/or sell copies of the Software, and to
-// permit persons to whom the Software is furnished to do so, subject to
-// the following conditions:
-// 
-// The above copyright notice and this permission notice shall be
-// included in all copies or substantial portions of the Software.
-// 
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
-// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
-// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
-// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
-// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
-// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-
-Element.Class = {
-    // Element.toggleClass(element, className) toggles the class being on/off
-    // Element.toggleClass(element, className1, className2) toggles between both classes,
-    //   defaulting to className1 if neither exist
-    toggle: function(element, className) {
-      if(Element.Class.has(element, className)) {
-        Element.Class.remove(element, className);
-        if(arguments.length == 3) Element.Class.add(element, arguments[2]);
-      } else {
-        Element.Class.add(element, className);
-        if(arguments.length == 3) Element.Class.remove(element, arguments[2]);
-      }
-    },
-
-    // gets space-delimited classnames of an element as an array
-    get: function(element) {
-      element = $(element);
-      return element.className.split(' ');
-    },
-
-    // functions adapted from original functions by Gavin Kistner
-    remove: function(element) {
-      element = $(element);
-      var regEx;
-      for(var i = 1; i < arguments.length; i++) {
-        regEx = new RegExp("^" + arguments[i] + "\\b\\s*|\\s*\\b" + arguments[i] + "\\b", 'g');
-        element.className = element.className.replace(regEx, '')
-      }
-    },
-
-    add: function(element) {
-      element = $(element);
-      for(var i = 1; i < arguments.length; i++) {
-        Element.Class.remove(element, arguments[i]);
-        element.className += (element.className.length > 0 ? ' ' : '') + arguments[i];
-      }
-    },
-
-    // returns true if all given classes exist in said element
-    has: function(element) {
-      element = $(element);
-      if(!element || !element.className) return false;
-      var regEx;
-      for(var i = 1; i < arguments.length; i++) {
-        regEx = new RegExp("\\b" + arguments[i] + "\\b");
-        if(!regEx.test(element.className)) return false;
-      }
-      return true;
-    },
-    
-    // expects arrays of strings and/or strings as optional paramters
-    // Element.Class.has_any(element, ['classA','classB','classC'], 'classD')
-    has_any: function(element) {
-      element = $(element);
-      if(!element || !element.className) return false;
-      var regEx;
-      for(var i = 1; i < arguments.length; i++) {
-        if((typeof arguments[i] == 'object') && 
-          (arguments[i].constructor == Array)) {
-          for(var j = 0; j < arguments[i].length; j++) {
-            regEx = new RegExp("\\b" + arguments[i][j] + "\\b");
-            if(regEx.test(element.className)) return true;
-          }
-        } else {
-          regEx = new RegExp("\\b" + arguments[i] + "\\b");
-          if(regEx.test(element.className)) return true;
-        }
-      }
-      return false;
-    },
-    
-    childrenWith: function(element, className) {
-      var children = $(element).getElementsByTagName('*');
-      var elements = new Array();
-      
-      for (var i = 0; i < children.length; i++) {
-        if (Element.Class.has(children[i], className)) {
-          elements.push(children[i]);
-          break;
-        }
-      }
-      
-      return elements;
-    }
-}
+// See scriptaculous.js for full license.
 
 /*--------------------------------------------------------------------------*/
 
 var Droppables = {
-  drops: false,
-  
+  drops: [],
+
   remove: function(element) {
-    for(var i = 0; i < this.drops.length; i++)
-      if(this.drops[i].element == element)
-        this.drops.splice(i,1);
+    this.drops = this.drops.reject(function(e) { return e==element });
   },
-  
+
   add: function(element) {
-    var element = $(element);
+    element = $(element);
     var options = Object.extend({
       greedy:     true,
       hoverclass: null  
     }, arguments[1] || {});
-    
+
     // cache containers
     if(options.containment) {
-      options._containers = new Array();
+      options._containers = [];
       var containment = options.containment;
       if((typeof containment == 'object') && 
         (containment.constructor == Array)) {
-        for(var i=0; i<containment.length; i++)
-          options._containers.push($(containment[i]));
+        containment.each( function(c) { options._containers.push($(c)) });
       } else {
         options._containers.push($(containment));
       }
-      options._containers_length = 
-        options._containers.length-1;
     }
-    
+
     Element.makePositioned(element); // fix IE
-    
     options.element = element;
-    
-    // activate the droppable    
-    if(!this.drops) this.drops = [];
+
     this.drops.push(options);
   },
-  
-  is_contained: function(element, drop) {
-    var containers = drop._containers;
+
+  isContained: function(element, drop) {
     var parentNode = element.parentNode;
-    var i = drop._containers_length;
-    do { if(parentNode==containers[i]) return true; } while (i--);
-    return false;
+    return drop._containers.detect(function(c) { return parentNode == c });
   },
-  
-  is_affected: function(pX, pY, element, drop) {
+
+  isAffected: function(pX, pY, element, drop) {
     return (
       (drop.element!=element) &&
       ((!drop._containers) ||
-        this.is_contained(element, drop)) &&
+        this.isContained(element, drop)) &&
       ((!drop.accept) ||
         (Element.Class.has_any(element, drop.accept))) &&
       Position.within(drop.element, pX, pY) );
   },
-  
+
   deactivate: function(drop) {
-    Element.Class.remove(drop.element, drop.hoverclass);
+    if(drop.hoverclass)
+      Element.Class.remove(drop.element, drop.hoverclass);
     this.last_active = null;
   },
-  
+
   activate: function(drop) {
     if(this.last_active) this.deactivate(this.last_active);
-    if(drop.hoverclass) {
+    if(drop.hoverclass)
       Element.Class.add(drop.element, drop.hoverclass);
-      this.last_active = drop;
-    }
+    this.last_active = drop;
   },
-  
+
   show: function(event, element) {
-    if(!this.drops) return;
+    if(!this.drops.length) return;
     var pX = Event.pointerX(event);
     var pY = Event.pointerY(event);
     Position.prepare();
-    
+
     var i = this.drops.length-1; do {
       var drop = this.drops[i];
-      if(this.is_affected(pX, pY, element, drop)) {
+      if(this.isAffected(pX, pY, element, drop)) {
         if(drop.onHover)
            drop.onHover(element, drop.element, Position.overlap(drop.overlap, drop.element));
         if(drop.greedy) { 
@@ -197,43 +83,41 @@ var Droppables = {
         }
       }
     } while (i--);
+    
+    if(this.last_active) this.deactivate(this.last_active);
   },
-  
+
   fire: function(event, element) {
     if(!this.last_active) return;
     Position.prepare();
-    
-    if (this.is_affected(Event.pointerX(event), Event.pointerY(event), element, this.last_active))
+
+    if (this.isAffected(Event.pointerX(event), Event.pointerY(event), element, this.last_active))
       if (this.last_active.onDrop) 
-        this.last_active.onDrop(element, this.last_active);
-    
+        this.last_active.onDrop(element, this.last_active.element);
   },
-  
+
   reset: function() {
     if(this.last_active)
       this.deactivate(this.last_active);
   }
 }
 
-Draggables = {
-  observers: new Array(),
+var Draggables = {
+  observers: [],
   addObserver: function(observer) {
     this.observers.push(observer);    
   },
   removeObserver: function(element) {  // element instead of obsever fixes mem leaks
-    for(var i = 0; i < this.observers.length; i++)
-      if(this.observers[i].element && (this.observers[i].element == element))
-        this.observers.splice(i,1);
+    this.observers = this.observers.reject( function(o) { return o.element==element });
   },
   notify: function(eventName, draggable) {  // 'onStart', 'onEnd'
-    for(var i = 0; i < this.observers.length; i++)
-      this.observers[i][eventName](draggable);
+    this.observers.invoke(eventName, draggable);
   }
 }
 
 /*--------------------------------------------------------------------------*/
 
-Draggable = Class.create();
+var Draggable = Class.create();
 Draggable.prototype = {
   initialize: function(element) {
     var options = Object.extend({
@@ -242,7 +126,8 @@ Draggable.prototype = {
         new Effect.Opacity(element, {duration:0.2, from:1.0, to:0.7}); 
       },
       reverteffect: function(element, top_offset, left_offset) {
-        new Effect.MoveBy(element, -top_offset, -left_offset, {duration:0.4});
+        var dur = Math.sqrt(Math.abs(top_offset^2)+Math.abs(left_offset^2))*0.02;
+        new Effect.MoveBy(element, -top_offset, -left_offset, {duration:dur});
       },
       endeffect: function(element) { 
          new Effect.Opacity(element, {duration:0.2, from:0.7, to:1.0}); 
@@ -250,12 +135,12 @@ Draggable.prototype = {
       zindex: 1000,
       revert: false
     }, arguments[1] || {});
-    
+
     this.element      = $(element);
     this.handle       = options.handle ? $(options.handle) : this.element;
-    
-    Element.makePositioned(this.element); // fix IE
-    
+
+    Element.makePositioned(this.element); // fix IE    
+
     this.offsetX      = 0;
     this.offsetY      = 0;
     this.originalLeft = this.currentLeft();
@@ -263,27 +148,34 @@ Draggable.prototype = {
     this.originalX    = this.element.offsetLeft;
     this.originalY    = this.element.offsetTop;
     this.originalZ    = parseInt(this.element.style.zIndex || "0");
-    
+
     this.options      = options;
-    
+
     this.active       = false;
     this.dragging     = false;   
-    
+
     this.eventMouseDown = this.startDrag.bindAsEventListener(this);
     this.eventMouseUp   = this.endDrag.bindAsEventListener(this);
     this.eventMouseMove = this.update.bindAsEventListener(this);
     this.eventKeypress  = this.keyPress.bindAsEventListener(this);
     
-    Event.observe(this.handle, "mousedown", this.eventMouseDown);
+    this.registerEvents();
+  },
+  destroy: function() {
+    Event.stopObserving(this.handle, "mousedown", this.eventMouseDown);
+    this.unregisterEvents();
+  },
+  registerEvents: function() {
     Event.observe(document, "mouseup", this.eventMouseUp);
     Event.observe(document, "mousemove", this.eventMouseMove);
     Event.observe(document, "keypress", this.eventKeypress);
+    Event.observe(this.handle, "mousedown", this.eventMouseDown);
   },
-  destroy: function() {
-    Event.stopObserving(this.handle, "mousedown", this.eventMouseDown);
-    Event.stopObserving(document, "mouseup", this.eventMouseUp);
-    Event.stopObserving(document, "mousemove", this.eventMouseMove);
-    Event.stopObserving(document, "keypress", this.eventKeypress);
+  unregisterEvents: function() {
+    //if(!this.active) return;
+    //Event.stopObserving(document, "mouseup", this.eventMouseUp);
+    //Event.stopObserving(document, "mousemove", this.eventMouseMove);
+    //Event.stopObserving(document, "keypress", this.eventKeypress);
   },
   currentLeft: function() {
     return parseInt(this.element.style.left || '0');
@@ -293,27 +185,42 @@ Draggable.prototype = {
   },
   startDrag: function(event) {
     if(Event.isLeftClick(event)) {
-      this.active = true;
       
-      var style = this.element.style;
-      this.originalY = this.element.offsetTop  - this.currentTop()  - this.originalTop;
-      this.originalX = this.element.offsetLeft - this.currentLeft() - this.originalLeft;
-      this.offsetY =  event.clientY - this.originalY - this.originalTop;
-      this.offsetX =  event.clientX - this.originalX - this.originalLeft;
+      // abort on form elements, fixes a Firefox issue
+      var src = Event.element(event);
+      if(src.tagName && (
+        src.tagName=='INPUT' ||
+        src.tagName=='SELECT' ||
+        src.tagName=='BUTTON' ||
+        src.tagName=='TEXTAREA')) return;
       
+      // this.registerEvents();
+      this.active = true;
+      var pointer = [Event.pointerX(event), Event.pointerY(event)];
+      var offsets = Position.cumulativeOffset(this.element);
+      this.offsetX =  (pointer[0] - offsets[0]);
+      this.offsetY =  (pointer[1] - offsets[1]);
       Event.stop(event);
     }
   },
   finishDrag: function(event, success) {
+    // this.unregisterEvents();
+
     this.active = false;
     this.dragging = false;
-    
+
+    if(this.options.ghosting) {
+      Position.relativize(this.element);
+      Element.remove(this._clone);
+      this._clone = null;
+    }
+
     if(success) Droppables.fire(event, this.element);
     Draggables.notify('onEnd', this);
-    
+
     var revert = this.options.revert;
     if(revert && typeof revert == 'function') revert = revert(this.element);
-      
+
     if(revert && this.options.reverteffect) {
       this.options.reverteffect(this.element, 
       this.currentTop()-this.originalTop,
@@ -322,12 +229,13 @@ Draggable.prototype = {
       this.originalLeft = this.currentLeft();
       this.originalTop  = this.currentTop();
     }
-    
+
     this.element.style.zIndex = this.originalZ;
-      
+
     if(this.options.endeffect) 
       this.options.endeffect(this.element);
-      
+
+
     Droppables.reset();
   },
   keyPress: function(event) {
@@ -347,13 +255,15 @@ Draggable.prototype = {
     this.dragging = false;
   },
   draw: function(event) {
+    var pointer = [Event.pointerX(event), Event.pointerY(event)];
+    var offsets = Position.cumulativeOffset(this.element);
+    offsets[0] -= this.currentLeft();
+    offsets[1] -= this.currentTop();
     var style = this.element.style;
-    this.originalX = this.element.offsetLeft - this.currentLeft() - this.originalLeft;
-    this.originalY = this.element.offsetTop  - this.currentTop()  - this.originalTop;
     if((!this.options.constraint) || (this.options.constraint=='horizontal'))
-      style.left = ((event.clientX - this.originalX) - this.offsetX) + "px";
+      style.left = (pointer[0] - offsets[0] - this.offsetX) + "px";
     if((!this.options.constraint) || (this.options.constraint=='vertical'))
-      style.top  = ((event.clientY - this.originalY) - this.offsetY) + "px";
+      style.top  = (pointer[1] - offsets[1] - this.offsetY) + "px";
     if(style.visibility=="hidden") style.visibility = ""; // fix gecko rendering
   },
   update: function(event) {
@@ -363,17 +273,24 @@ Draggable.prototype = {
         this.dragging = true;
         if(style.position=="") style.position = "relative";
         style.zIndex = this.options.zindex;
+
+        if(this.options.ghosting) {
+          this._clone = this.element.cloneNode(true);
+          Position.absolutize(this.element);
+          this.element.parentNode.insertBefore(this._clone, this.element);
+        }
+
         Draggables.notify('onStart', this);
         if(this.options.starteffect) this.options.starteffect(this.element);
       }
-      
+
       Droppables.show(event, this.element);
       this.draw(event);
       if(this.options.change) this.options.change(this);
-      
+
       // fix AppleWebKit rendering
       if(navigator.appVersion.indexOf('AppleWebKit')>0) window.scrollBy(0,0); 
-      
+
       Event.stop(event);
    }
   }
@@ -381,7 +298,7 @@ Draggable.prototype = {
 
 /*--------------------------------------------------------------------------*/
 
-SortableObserver = Class.create();
+var SortableObserver = Class.create();
 SortableObserver.prototype = {
   initialize: function(element, observer) {
     this.element   = $(element);
@@ -391,147 +308,197 @@ SortableObserver.prototype = {
   onStart: function() {
     this.lastValue = Sortable.serialize(this.element);
   },
-  onEnd: function() {    
+  onEnd: function() {
+    Sortable.unmark();
     if(this.lastValue != Sortable.serialize(this.element))
       this.observer(this.element)
   }
 }
 
-Sortable = {
+var Sortable = {
   sortables: new Array(),
   options: function(element){
-    var element = $(element);
-    for(var i=0;i<this.sortables.length;i++)
-      if(this.sortables[i].element == element)
-        return this.sortables[i];
-    return null;        
+    element = $(element);
+    return this.sortables.detect(function(s) { return s.element == element });
   },
   destroy: function(element){
-    var element = $(element);
-    for(var i=0;i<this.sortables.length;i++) {
-      if(this.sortables[i].element == element) {
-        var s = this.sortables[i];
-        Draggables.removeObserver(s.element);
-        for(var j=0;j<s.droppables.length;j++)
-          Droppables.remove(s.droppables[j]);
-        for(var j=0;j<s.draggables.length;j++)
-          s.draggables[j].destroy();
-        this.sortables.splice(i,1);
-      }
-    }
+    element = $(element);
+    this.sortables.findAll(function(s) { return s.element == element }).each(function(s){
+      Draggables.removeObserver(s.element);
+      s.droppables.each(function(d){ Droppables.remove(d) });
+      s.draggables.invoke('destroy');
+    });
+    this.sortables = this.sortables.reject(function(s) { return s.element == element });
   },
   create: function(element) {
-    var element = $(element);
+    element = $(element);
     var options = Object.extend({ 
       element:     element,
       tag:         'li',       // assumes li children, override with tag: 'tagname'
+      dropOnEmpty: false,
+      tree:        false,      // fixme: unimplemented
       overlap:     'vertical', // one of 'vertical', 'horizontal'
       constraint:  'vertical', // one of 'vertical', 'horizontal', false
       containment: element,    // also takes array of elements (or id's); or false
       handle:      false,      // or a CSS class
       only:        false,
       hoverclass:  null,
+      ghosting:    false,
       onChange:    function() {},
       onUpdate:    function() {}
     }, arguments[1] || {});
-    
+
     // clear any old sortable with same element
     this.destroy(element);
-    
+
     // build options for the draggables
     var options_for_draggable = {
       revert:      true,
+      ghosting:    options.ghosting,
       constraint:  options.constraint,
-      handle:      handle };
+      handle:      options.handle };
+
     if(options.starteffect)
       options_for_draggable.starteffect = options.starteffect;
+
     if(options.reverteffect)
       options_for_draggable.reverteffect = options.reverteffect;
+    else
+      if(options.ghosting) options_for_draggable.reverteffect = function(element) {
+        element.style.top  = 0;
+        element.style.left = 0;
+      };
+
     if(options.endeffect)
       options_for_draggable.endeffect = options.endeffect;
+
     if(options.zindex)
       options_for_draggable.zindex = options.zindex;
-    
+
     // build options for the droppables  
     var options_for_droppable = {
       overlap:     options.overlap,
       containment: options.containment,
       hoverclass:  options.hoverclass,
-      onHover: function(element, dropon, overlap) { 
-        if(overlap>0.5) {
-          if(dropon.previousSibling != element) {
-            var oldParentNode = element.parentNode;
-            element.style.visibility = "hidden"; // fix gecko rendering
-            dropon.parentNode.insertBefore(element, dropon);
-            if(dropon.parentNode!=oldParentNode && oldParentNode.sortable) 
-              oldParentNode.sortable.onChange(element);
-            if(dropon.parentNode.sortable)
-              dropon.parentNode.sortable.onChange(element);
-          }
-        } else {                
-          var nextElement = dropon.nextSibling || null;
-          if(nextElement != element) {
-            var oldParentNode = element.parentNode;
-            element.style.visibility = "hidden"; // fix gecko rendering
-            dropon.parentNode.insertBefore(element, nextElement);
-            if(dropon.parentNode!=oldParentNode && oldParentNode.sortable) 
-              oldParentNode.sortable.onChange(element);
-            if(dropon.parentNode.sortable)
-              dropon.parentNode.sortable.onChange(element);
-          }
-        }
-      }
+      onHover:     Sortable.onHover,
+      greedy:      !options.dropOnEmpty
     }
 
     // fix for gecko engine
     Element.cleanWhitespace(element); 
-    
+
     options.draggables = [];
     options.droppables = [];
-    
-    // make it so 
-    var elements = element.childNodes;
-    for (var i = 0; i < elements.length; i++) 
-      if(elements[i].tagName && elements[i].tagName==options.tag.toUpperCase() &&
-        (!options.only || (Element.Class.has(elements[i], options.only)))) {
-        
-        // handles are per-draggable
-        var handle = options.handle ? 
-          Element.Class.childrenWith(elements[i], options.handle)[0] : elements[i];
-        
-        options.draggables.push(new Draggable(elements[i], Object.extend(options_for_draggable, { handle: handle })));
-        
-        Droppables.add(elements[i], options_for_droppable);
-        options.droppables.push(elements[i]);
-        
-      }
-      
+
+    // make it so
+
+    // drop on empty handling
+    if(options.dropOnEmpty) {
+      Droppables.add(element,
+        {containment: options.containment, onHover: Sortable.onEmptyHover, greedy: false});
+      options.droppables.push(element);
+    }
+
+    (this.findElements(element, options) || []).each( function(e) {
+      // handles are per-draggable
+      var handle = options.handle ? 
+        Element.Class.childrenWith(e, options.handle)[0] : e;    
+      options.draggables.push(
+        new Draggable(e, Object.extend(options_for_draggable, { handle: handle })));
+      Droppables.add(e, options_for_droppable);
+      options.droppables.push(e);      
+    });
+
     // keep reference
     this.sortables.push(options);
-    
+
     // for onupdate
     Draggables.addObserver(new SortableObserver(element, options.onUpdate));
 
   },
+
+  // return all suitable-for-sortable elements in a guaranteed order
+  findElements: function(element, options) {
+    if(!element.hasChildNodes()) return null;
+    var elements = [];
+    $A(element.childNodes).each( function(e) {
+      if(e.tagName && e.tagName==options.tag.toUpperCase() &&
+        (!options.only || (Element.Class.has(e, options.only))))
+          elements.push(e);
+      if(options.tree) {
+        var grandchildren = this.findElements(e, options);
+        if(grandchildren) elements.push(grandchildren);
+      }
+    });
+
+    return (elements.length>0 ? elements.flatten() : null);
+  },
+
+  onHover: function(element, dropon, overlap) {
+    if(overlap>0.5) {
+      Sortable.mark(dropon, 'before');
+      if(dropon.previousSibling != element) {
+        var oldParentNode = element.parentNode;
+        element.style.visibility = "hidden"; // fix gecko rendering
+        dropon.parentNode.insertBefore(element, dropon);
+        if(dropon.parentNode!=oldParentNode) 
+          Sortable.options(oldParentNode).onChange(element);
+        Sortable.options(dropon.parentNode).onChange(element);
+      }
+    } else {
+      Sortable.mark(dropon, 'after');
+      var nextElement = dropon.nextSibling || null;
+      if(nextElement != element) {
+        var oldParentNode = element.parentNode;
+        element.style.visibility = "hidden"; // fix gecko rendering
+        dropon.parentNode.insertBefore(element, nextElement);
+        if(dropon.parentNode!=oldParentNode) 
+          Sortable.options(oldParentNode).onChange(element);
+        Sortable.options(dropon.parentNode).onChange(element);
+      }
+    }
+  },
+
+  onEmptyHover: function(element, dropon) {
+    if(element.parentNode!=dropon) {
+      dropon.appendChild(element);
+    }
+  },
+
+  unmark: function() {
+    if(Sortable._marker) Element.hide(Sortable._marker);
+  },
+
+  mark: function(dropon, position) {
+    // mark on ghosting only
+    var sortable = Sortable.options(dropon.parentNode);
+    if(sortable && !sortable.ghosting) return; 
+
+    if(!Sortable._marker) {
+      Sortable._marker = $('dropmarker') || document.createElement('DIV');
+      Element.hide(Sortable._marker);
+      Element.Class.add(Sortable._marker, 'dropmarker');
+      Sortable._marker.style.position = 'absolute';
+      document.getElementsByTagName("body").item(0).appendChild(Sortable._marker);
+    }    
+    var offsets = Position.cumulativeOffset(dropon);
+    Sortable._marker.style.top  = offsets[1] + 'px';
+    if(position=='after') Sortable._marker.style.top = (offsets[1]+dropon.clientHeight) + 'px';
+    Sortable._marker.style.left = offsets[0] + 'px';
+    Element.show(Sortable._marker);
+  },
+
   serialize: function(element) {
-    var element = $(element);
+    element = $(element);
     var sortableOptions = this.options(element);
     var options = Object.extend({
       tag:  sortableOptions.tag,
       only: sortableOptions.only,
       name: element.id
     }, arguments[1] || {});
-    
-    var items = $(element).childNodes;
-    var queryComponents = new Array();
- 
-    for(var i=0; i<items.length; i++)
-      if(items[i].tagName && items[i].tagName==options.tag.toUpperCase() &&
-        (!options.only || (Element.Class.has(items[i], options.only))))
-        queryComponents.push(
-          encodeURIComponent(options.name) + "[]=" + 
-          encodeURIComponent(items[i].id.split("_")[1]));
-
-    return queryComponents.join("&");
+    return $A(element.childNodes).collect( function(item) { 
+      return (encodeURIComponent(options.name) + "[]=" + 
+              encodeURIComponent(item.id.split("_")[1]));
+    }).join("&");
   }
-} 
\ No newline at end of file
+}
\ No newline at end of file