path: root/railties/html/javascripts/controls.js

// Copyright (c) 2005 Thomas Fuchs (http://script.aculo.us, http://mir.aculo.us)
//           (c) 2005 Ivan Krstic (http://blogs.law.harvard.edu/ivan)
//           (c) 2005 Jon Tirsen (http://www.tirsen.com)
// Contributors:
//  Richard Livsey
//  Rahul Bhargava
//  Rob Wills
// 
// See scriptaculous.js for full license.

// Autocompleter.Base handles all the autocompletion functionality 
// that's independent of the data source for autocompletion. This
// includes drawing the autocompletion menu, observing keyboard
// and mouse events, and similar.
//
// Specific autocompleters need to provide, at the very least, 
// a getUpdatedChoices function that will be invoked every time
// the text inside the monitored textbox changes. This method 
// should get the text for which to provide autocompletion by
// invoking this.getToken(), NOT by directly accessing
// this.element.value. This is to allow incremental tokenized
// autocompletion. Specific auto-completion logic (AJAX, etc)
// belongs in getUpdatedChoices.
//
// Tokenized incremental autocompletion is enabled automatically
// when an autocompleter is instantiated with the 'tokens' option
// in the options parameter, e.g.:
// new Ajax.Autocompleter('id','upd', '/url/', { tokens: ',' });
// will incrementally autocomplete with a comma as the token.
// Additionally, ',' in the above example can be replaced with
// a token array, e.g. { tokens: [',', '\n'] } which
// enables autocompletion on multiple tokens. This is most 
// useful when one of the tokens is \n (a newline), as it 
// allows smart autocompletion after linebreaks.

var Autocompleter = {}
Autocompleter.Base = function() {};
Autocompleter.Base.prototype = {
  baseInitialize: function(element, update, options) {
    this.element     = $(element); 
    this.update      = $(update);  
    this.hasFocus    = false; 
    this.changed     = false; 
    this.active      = false; 
    this.index       = 0;     
    this.entryCount  = 0;

    if (this.setOptions)
      this.setOptions(options);
    else
      this.options = options || {};

    this.options.paramName    = this.options.paramName || this.element.name;
    this.options.tokens       = this.options.tokens || [];
    this.options.frequency    = this.options.frequency || 0.4;
    this.options.minChars     = this.options.minChars || 1;
    this.options.onShow       = this.options.onShow || 
    function(element, update){ 
      if(!update.style.position || update.style.position=='absolute') {
        update.style.position = 'absolute';
        Position.clone(element, update, {setHeight: false, offsetTop: element.offsetHeight});
      }
      Effect.Appear(update,{duration:0.15});
    };
    this.options.onHide = this.options.onHide || 
    function(element, update){ new Effect.Fade(update,{duration:0.15}) };

    if (typeof(this.options.tokens) == 'string') 
      this.options.tokens = new Array(this.options.tokens);

    this.observer = null;
    
    this.element.setAttribute('autocomplete','off');

    Element.hide(this.update);

    Event.observe(this.element, "blur", this.onBlur.bindAsEventListener(this));
    Event.observe(this.element, "keypress", this.onKeyPress.bindAsEventListener(this));
  },

  show: function() {
    if(Element.getStyle(this.update, 'display')=='none') this.options.onShow(this.element, this.update);
    if(!this.iefix && 
      (navigator.appVersion.indexOf('MSIE')>0) &&
      (navigator.userAgent.indexOf('Opera')<0) &&
      (Element.getStyle(this.update, 'position')=='absolute')) {
      new Insertion.After(this.update, 
       '<iframe id="' + this.update.id + '_iefix" '+
       'style="display:none;position:absolute;filter:progid:DXImageTransform.Microsoft.Alpha(opacity=0);" ' +
       'src="javascript:false;" frameborder="0" scrolling="no"></iframe>');
      this.iefix = $(this.update.id+'_iefix');
    }
    if(this.iefix) setTimeout(this.fixIEOverlapping.bind(this), 50);
  },
  
  fixIEOverlapping: function() {
    Position.clone(this.update, this.iefix);
    this.iefix.style.zIndex = 1;
    this.update.style.zIndex = 2;
    Element.show(this.iefix);
  },

  hide: function() {
    this.stopIndicator();
    if(Element.getStyle(this.update, 'display')!='none') this.options.onHide(this.element, this.update);
    if(this.iefix) Element.hide(this.iefix);
  },

  startIndicator: function() {
    if(this.options.indicator) Element.show(this.options.indicator);
  },

  stopIndicator: function() {
    if(this.options.indicator) Element.hide(this.options.indicator);
  },

  onKeyPress: function(event) {
    if(this.active)
      switch(event.keyCode) {
       case Event.KEY_TAB:
       case Event.KEY_RETURN:
         this.selectEntry();
         Event.stop(event);
       case Event.KEY_ESC:
         this.hide();
         this.active = false;
         Event.stop(event);
         return;
       case Event.KEY_LEFT:
       case Event.KEY_RIGHT:
         return;
       case Event.KEY_UP:
         this.markPrevious();
         this.render();
         if(navigator.appVersion.indexOf('AppleWebKit')>0) Event.stop(event);
         return;
       case Event.KEY_DOWN:
         this.markNext();
         this.render();
         if(navigator.appVersion.indexOf('AppleWebKit')>0) Event.stop(event);
         return;
      }
     else 
       if(event.keyCode==Event.KEY_TAB || event.keyCode==Event.KEY_RETURN || 
         (navigator.appVersion.indexOf('AppleWebKit') > 0 && event.keyCode == 0)) return;

    this.changed = true;
    this.hasFocus = true;

    if(this.observer) clearTimeout(this.observer);
      this.observer = 
        setTimeout(this.onObserverEvent.bind(this), this.options.frequency*1000);
  },

  activate: function() {
    this.changed = false;
    this.hasFocus = true;
    this.getUpdatedChoices();
  },

  onHover: function(event) {
    var element = Event.findElement(event, 'LI');
    if(this.index != element.autocompleteIndex) 
    {
        this.index = element.autocompleteIndex;
        this.render();
    }
    Event.stop(event);
  },
  
  onClick: function(event) {
    var element = Event.findElement(event, 'LI');
    this.index = element.autocompleteIndex;
    this.selectEntry();
    this.hide();
  },
  
  onBlur: function(event) {
    // needed to make click events working
    setTimeout(this.hide.bind(this), 250);
    this.hasFocus = false;
    this.active = false;     
  }, 
  
  render: function() {
    if(this.entryCount > 0) {
      for (var i = 0; i < this.entryCount; i++)
        this.index==i ? 
          Element.addClassName(this.getEntry(i),"selected") : 
          Element.removeClassName(this.getEntry(i),"selected");
        
      if(this.hasFocus) { 
        this.show();
        this.active = true;
      }
    } else {
      this.active = false;
      this.hide();
    }
  },
  
  markPrevious: function() {
    if(this.index > 0) this.index--
      else this.index = this.entryCount-1;
  },
  
  markNext: function() {
    if(this.index < this.entryCount-1) this.index++
      else this.index = 0;
  },
  
  getEntry: function(index) {
    return this.update.firstChild.childNodes[index];
  },
  
  getCurrentEntry: function() {
    return this.getEntry(this.index);
  },
  
  selectEntry: function() {
    this.active = false;
    this.updateElement(this.getCurrentEntry());
  },

  updateElement: function(selectedElement) {
    if (this.options.updateElement) {
      this.options.updateElement(selectedElement);
      return;
    }
    var value = '';
    if (this.options.select) {
      var nodes = document.getElementsByClassName(this.options.select, selectedElement) || [];
      if(nodes.length>0) value = Element.collectTextNodes(nodes[0], this.options.select);
    } else
      value = Element.collectTextNodesIgnoreClass(selectedElement, 'informal');
    
    var lastTokenPos = this.findLastToken();
    if (lastTokenPos != -1) {
      var newValue = this.element.value.substr(0, lastTokenPos + 1);
      var whitespace = this.element.value.substr(lastTokenPos + 1).match(/^\s+/);
      if (whitespace)
        newValue += whitespace[0];
      this.element.value = newValue + value;
    } else {
      this.element.value = value;
    }
    this.element.focus();
    
    if (this.options.afterUpdateElement)
      this.options.afterUpdateElement(this.element, selectedElement);
  },

  updateChoices: function(choices) {
    if(!this.changed && this.hasFocus) {
      this.update.innerHTML = choices;
      Element.cleanWhitespace(this.update);
      Element.cleanWhitespace(this.update.firstChild);

      if(this.update.firstChild && this.update.firstChild.childNodes) {
        this.entryCount = 
          this.update.firstChild.childNodes.length;
        for (var i = 0; i < this.entryCount; i++) {
          var entry = this.getEntry(i);
          entry.autocompleteIndex = i;
          this.addObservers(entry);
        }
      } else { 
        this.entryCount = 0;
      }

      this.stopIndicator();

      this.index = 0;
      this.render();
    }
  },

  addObservers: function(element) {
    Event.observe(element, "mouseover", this.onHover.bindAsEventListener(this));
    Event.observe(element, "click", this.onClick.bindAsEventListener(this));
  },

  onObserverEvent: function() {
    this.changed = false;   
    if(this.getToken().length>=this.options.minChars) {
      this.startIndicator();
      this.getUpdatedChoices();
    } else {
      this.active = false;
      this.hide();
    }
  },

  getToken: function() {
    var tokenPos = this.findLastToken();
    if (tokenPos != -1)
      var ret = this.element.value.substr(tokenPos + 1).replace(/^\s+/,'').replace(/\s+$/,'');
    else
      var ret = this.element.value;

    return /\n/.test(ret) ? '' : ret;
  },

  findLastToken: function() {
    var lastTokenPos = -1;

    for (var i=0; i<this.options.tokens.length; i++) {
      var thisTokenPos = this.element.value.lastIndexOf(this.options.tokens[i]);
      if (thisTokenPos > lastTokenPos)
        lastTokenPos = thisTokenPos;
    }
    return lastTokenPos;
  }
}

Ajax.Autocompleter = Class.create();
Object.extend(Object.extend(Ajax.Autocompleter.prototype, Autocompleter.Base.prototype), {
  initialize: function(element, update, url, options) {
    this.baseInitialize(element, update, options);
    this.options.asynchronous  = true;
    this.options.onComplete    = this.onComplete.bind(this);
    this.options.defaultParams = this.options.parameters || null;
    this.url                   = url;
  },

  getUpdatedChoices: function() {
    entry = encodeURIComponent(this.options.paramName) + '=' + 
      encodeURIComponent(this.getToken());

    this.options.parameters = this.options.callback ?
      this.options.callback(this.element, entry) : entry;

    if(this.options.defaultParams) 
      this.options.parameters += '&' + this.options.defaultParams;

    new Ajax.Request(this.url, this.options);
  },

  onComplete: function(request) {
    this.updateChoices(request.responseText);
  }

});

// The local array autocompleter. Used when you'd prefer to
// inject an array of autocompletion options into the page, rather
// than sending out Ajax queries, which can be quite slow sometimes.
//
// The constructor takes four parameters. The first two are, as usual,
// the id of the monitored textbox, and id of the autocompletion menu.
// The third is the array you want to autocomplete from, and the fourth
// is the options block.
//
// Extra local autocompletion options:
// - choices - How many autocompletion choices to offer
//
// - partialSearch - If false, the autocompleter will match entered
//                    text only at the beginning of strings in the 
//                    autocomplete array. Defaults to true, which will
//                    match text at the beginning of any *word* in the
//                    strings in the autocomplete array. If you want to
//                    search anywhere in the string, additionally set
//                    the option fullSearch to true (default: off).
//
// - fullSsearch - Search anywhere in autocomplete array strings.
//
// - partialChars - How many characters to enter before triggering
//                   a partial match (unlike minChars, which defines
//                   how many characters are required to do any match
//                   at all). Defaults to 2.
//
// - ignoreCase - Whether to ignore case when autocompleting.
//                 Defaults to true.
//
// It's possible to pass in a custom function as the 'selector' 
// option, if you prefer to write your own autocompletion logic.
// In that case, the other options above will not apply unless
// you support them.

Autocompleter.Local = Class.create();
Autocompleter.Local.prototype = Object.extend(new Autocompleter.Base(), {
  initialize: function(element, update, array, options) {
    this.baseInitialize(element, update, options);
    this.options.array = array;
  },

  getUpdatedChoices: function() {
    this.updateChoices(this.options.selector(this));
  },

  setOptions: function(options) {
    this.options = Object.extend({
      choices: 10,
      partialSearch: true,
      partialChars: 2,
      ignoreCase: true,
      fullSearch: false,
      selector: function(instance) {
        var ret       = []; // Beginning matches
        var partial   = []; // Inside matches
        var entry     = instance.getToken();
        var count     = 0;

        for (var i = 0; i < instance.options.array.length &&  
          ret.length < instance.options.choices ; i++) { 

          var elem = instance.options.array[i];
          var foundPos = instance.options.ignoreCase ? 
            elem.toLowerCase().indexOf(entry.toLowerCase()) : 
            elem.indexOf(entry);

          while (foundPos != -1) {
            if (foundPos == 0 && elem.length != entry.length) { 
              ret.push("<li><strong>" + elem.substr(0, entry.length) + "</strong>" + 
                elem.substr(entry.length) + "</li>");
              break;
            } else if (entry.length >= instance.options.partialChars && 
              instance.options.partialSearch && foundPos != -1) {
              if (instance.options.fullSearch || /\s/.test(elem.substr(foundPos-1,1))) {
                partial.push("<li>" + elem.substr(0, foundPos) + "<strong>" +
                  elem.substr(foundPos, entry.length) + "</strong>" + elem.substr(
                  foundPos + entry.length) + "</li>");
                break;
              }
            }

            foundPos = instance.options.ignoreCase ? 
              elem.toLowerCase().indexOf(entry.toLowerCase(), foundPos + 1) : 
              elem.indexOf(entry, foundPos + 1);

          }
        }
        if (partial.length)
          ret = ret.concat(partial.slice(0, instance.options.choices - ret.length))
        return "<ul>" + ret.join('') + "</ul>";
      }
    }, options || {});
  }
});

// AJAX in-place editor
//
// see documentation on http://wiki.script.aculo.us/scriptaculous/show/Ajax.InPlaceEditor

// Use this if you notice weird scrolling problems on some browsers,
// the DOM might be a bit confused when this gets called so do this
// waits 1 ms (with setTimeout) until it does the activation
Field.scrollFreeActivate = function(field) {
  setTimeout(function() {
    Field.activate(field);
  }, 1);
}

Ajax.InPlaceEditor = Class.create();
Ajax.InPlaceEditor.defaultHighlightColor = "#FFFF99";
Ajax.InPlaceEditor.prototype = {
  initialize: function(element, url, options) {
    this.url = url;
    this.element = $(element);

    this.options = Object.extend({
      okButton: true,
      okText: "ok",
      cancelLink: true,
      cancelText: "cancel",
      savingText: "Saving...",
      clickToEditText: "Click to edit",
      okText: "ok",
      rows: 1,
      onComplete: function(transport, element) {
        new Effect.Highlight(element, {startcolor: this.options.highlightcolor});
      },
      onFailure: function(transport) {
        alert("Error communicating with the server: " + transport.responseText.stripTags());
      },
      callback: function(form) {
        return Form.serialize(form);
      },
      handleLineBreaks: true,
      loadingText: 'Loading...',
      savingClassName: 'inplaceeditor-saving',
      loadingClassName: 'inplaceeditor-loading',
      formClassName: 'inplaceeditor-form',
      highlightcolor: Ajax.InPlaceEditor.defaultHighlightColor,
      highlightendcolor: "#FFFFFF",
      externalControl: null,
      submitOnBlur: false,
      ajaxOptions: {},
      evalScripts: false
    }, options || {});

    if(!this.options.formId && this.element.id) {
      this.options.formId = this.element.id + "-inplaceeditor";
      if ($(this.options.formId)) {
        // there's already a form with that name, don't specify an id
        this.options.formId = null;
      }
    }
    
    if (this.options.externalControl) {
      this.options.externalControl = $(this.options.externalControl);
    }
    
    this.originalBackground = Element.getStyle(this.element, 'background-color');
    if (!this.originalBackground) {
      this.originalBackground = "transparent";
    }
    
    this.element.title = this.options.clickToEditText;
    
    this.onclickListener = this.enterEditMode.bindAsEventListener(this);
    this.mouseoverListener = this.enterHover.bindAsEventListener(this);
    this.mouseoutListener = this.leaveHover.bindAsEventListener(this);
    Event.observe(this.element, 'click', this.onclickListener);
    Event.observe(this.element, 'mouseover', this.mouseoverListener);
    Event.observe(this.element, 'mouseout', this.mouseoutListener);
    if (this.options.externalControl) {
      Event.observe(this.options.externalControl, 'click', this.onclickListener);
      Event.observe(this.options.externalControl, 'mouseover', this.mouseoverListener);
      Event.observe(this.options.externalControl, 'mouseout', this.mouseoutListener);
    }
  },
  enterEditMode: function(evt) {
    if (this.saving) return;
    if (this.editing) return;
    this.editing = true;
    this.onEnterEditMode();
    if (this.options.externalControl) {
      Element.hide(this.options.externalControl);
    }
    Element.hide(this.element);
    this.createForm();
    this.element.parentNode.insertBefore(this.form, this.element);
    Field.scrollFreeActivate(this.editField);
    // stop the event to avoid a page refresh in Safari
    if (evt) {
      Event.stop(evt);
    }
    return false;
  },
  createForm: function() {
    this.form = document.createElement("form");
    this.form.id = this.options.formId;
    Element.addClassName(this.form, this.options.formClassName)
    this.form.onsubmit = this.onSubmit.bind(this);

    this.createEditField();

    if (this.options.textarea) {
      var br = document.createElement("br");
      this.form.appendChild(br);
    }

    if (this.options.okButton) {
      okButton = document.createElement("input");
      okButton.type = "submit";
      okButton.value = this.options.okText;
      okButton.className = 'editor_ok_button';
      this.form.appendChild(okButton);
    }

    if (this.options.cancelLink) {
      cancelLink = document.createElement("a");
      cancelLink.href = "#";
      cancelLink.appendChild(document.createTextNode(this.options.cancelText));
      cancelLink.onclick = this.onclickCancel.bind(this);
      cancelLink.className = 'editor_cancel';      
      this.form.appendChild(cancelLink);
    }
  },
  hasHTMLLineBreaks: function(string) {
    if (!this.options.handleLineBreaks) return false;
    return string.match(/<br/i) || string.match(/<p>/i);
  },
  convertHTMLLineBreaks: function(string) {
    return string.replace(/<br>/gi, "\n").replace(/<br\/>/gi, "\n").replace(/<\/p>/gi, "\n").replace(/<p>/gi, "");
  },
  createEditField: function() {
    var text;
    if(this.options.loadTextURL) {
      text = this.options.loadingText;
    } else {
      text = this.getText();
    }

    var obj = this;
    
    if (this.options.rows == 1 && !this.hasHTMLLineBreaks(text)) {
      this.options.textarea = false;
      var textField = document.createElement("input");
      textField.obj = this;
      textField.type = "text";
      textField.name = "value";
      textField.value = text;
      textField.style.backgroundColor = this.options.highlightcolor;
      textField.className = 'editor_field';
      var size = this.options.size || this.options.cols || 0;
      if (size != 0) textField.size = size;
      if (this.options.submitOnBlur)
        textField.onblur = this.onSubmit.bind(this);
      this.editField = textField;
    } else {
      this.options.textarea = true;
      var textArea = document.createElement("textarea");
      textArea.obj = this;
      textArea.name = "value";
      textArea.value = this.convertHTMLLineBreaks(text);
      textArea.rows = this.options.rows;
      textArea.cols = this.options.cols || 40;
      textArea.className = 'editor_field';      
      if (this.options.submitOnBlur)
        textArea.onblur = this.onSubmit.bind(this);
      this.editField = textArea;
    }
    
    if(this.options.loadTextURL) {
      this.loadExternalText();
    }
    this.form.appendChild(this.editField);
  },
  getText: function() {
    return this.element.innerHTML;
  },
  loadExternalText: function() {
    Element.addClassName(this.form, this.options.loadingClassName);
    this.editField.disabled = true;
    new Ajax.Request(
      this.options.loadTextURL,
      Object.extend({
        asynchronous: true,
        onComplete: this.onLoadedExternalText.bind(this)
      }, this.options.ajaxOptions)
    );
  },
  onLoadedExternalText: function(transport) {
    Element.removeClassName(this.form, this.options.loadingClassName);
    this.editField.disabled = false;
    this.editField.value = transport.responseText.stripTags();
  },
  onclickCancel: function() {
    this.onComplete();
    this.leaveEditMode();
    return false;
  },
  onFailure: function(transport) {
    this.options.onFailure(transport);
    if (this.oldInnerHTML) {
      this.element.innerHTML = this.oldInnerHTML;
      this.oldInnerHTML = null;
    }
    return false;
  },
  onSubmit: function() {
    // onLoading resets these so we need to save them away for the Ajax call
    var form = this.form;
    var value = this.editField.value;
    
    // do this first, sometimes the ajax call returns before we get a chance to switch on Saving...
    // which means this will actually switch on Saving... *after* we've left edit mode causing Saving...
    // to be displayed indefinitely
    this.onLoading();
    
    if (this.options.evalScripts) {
      new Ajax.Request(
        this.url, Object.extend({
          parameters: this.options.callback(form, value),
          onComplete: this.onComplete.bind(this),
          onFailure: this.onFailure.bind(this),
          asynchronous:true, 
          evalScripts:true
        }, this.options.ajaxOptions));
    } else  {
      new Ajax.Updater(
        { success: this.element,
          // don't update on failure (this could be an option)
          failure: null }, 
        this.url, Object.extend({
          parameters: this.options.callback(form, value),
          onComplete: this.onComplete.bind(this),
          onFailure: this.onFailure.bind(this)
        }, this.options.ajaxOptions));
    }
    // stop the event to avoid a page refresh in Safari
    if (arguments.length > 1) {
      Event.stop(arguments[0]);
    }
    return false;
  },
  onLoading: function() {
    this.saving = true;
    this.removeForm();
    this.leaveHover();
    this.showSaving();
  },
  showSaving: function() {
    this.oldInnerHTML = this.element.innerHTML;
    this.element.innerHTML = this.options.savingText;
    Element.addClassName(this.element, this.options.savingClassName);
    this.element.style.backgroundColor = this.originalBackground;
    Element.show(this.element);
  },
  removeForm: function() {
    if(this.form) {
      if (this.form.parentNode) Element.remove(this.form);
      this.form = null;
    }
  },
  enterHover: function() {
    if (this.saving) return;
    this.element.style.backgroundColor = this.options.highlightcolor;
    if (this.effect) {
      this.effect.cancel();
    }
    Element.addClassName(this.element, this.options.hoverClassName)
  },
  leaveHover: function() {
    if (this.options.backgroundColor) {
      this.element.style.backgroundColor = this.oldBackground;
    }
    Element.removeClassName(this.element, this.options.hoverClassName)
    if (this.saving) return;
    this.effect = new Effect.Highlight(this.element, {
      startcolor: this.options.highlightcolor,
      endcolor: this.options.highlightendcolor,
      restorecolor: this.originalBackground
    });
  },
  leaveEditMode: function() {
    Element.removeClassName(this.element, this.options.savingClassName);
    this.removeForm();
    this.leaveHover();
    this.element.style.backgroundColor = this.originalBackground;
    Element.show(this.element);
    if (this.options.externalControl) {
      Element.show(this.options.externalControl);
    }
    this.editing = false;
    this.saving = false;
    this.oldInnerHTML = null;
    this.onLeaveEditMode();
  },
  onComplete: function(transport) {
    this.leaveEditMode();
    this.options.onComplete.bind(this)(transport, this.element);
  },
  onEnterEditMode: function() {},
  onLeaveEditMode: function() {},
  dispose: function() {
    if (this.oldInnerHTML) {
      this.element.innerHTML = this.oldInnerHTML;
    }
    this.leaveEditMode();
    Event.stopObserving(this.element, 'click', this.onclickListener);
    Event.stopObserving(this.element, 'mouseover', this.mouseoverListener);
    Event.stopObserving(this.element, 'mouseout', this.mouseoutListener);
    if (this.options.externalControl) {
      Event.stopObserving(this.options.externalControl, 'click', this.onclickListener);
      Event.stopObserving(this.options.externalControl, 'mouseover', this.mouseoverListener);
      Event.stopObserving(this.options.externalControl, 'mouseout', this.mouseoutListener);
    }
  }
};

Ajax.InPlaceCollectionEditor = Class.create();
Object.extend(Ajax.InPlaceCollectionEditor.prototype, Ajax.InPlaceEditor.prototype);
Object.extend(Ajax.InPlaceCollectionEditor.prototype, {
  createEditField: function() {
    if (!this.cached_selectTag) {
      var selectTag = document.createElement("select");
      var collection = this.options.collection || [];
      var optionTag;
      collection.each(function(e,i) {
        optionTag = document.createElement("option");
        optionTag.value = (e instanceof Array) ? e[0] : e;
        if(this.options.value==optionTag.value) optionTag.selected = true;
        optionTag.appendChild(document.createTextNode((e instanceof Array) ? e[1] : e));
        selectTag.appendChild(optionTag);
      }.bind(this));
      this.cached_selectTag = selectTag;
    }

    this.editField = this.cached_selectTag;
    if(this.options.loadTextURL) this.loadExternalText();
    this.form.appendChild(this.editField);
    this.options.callback = function(form, value) {
      return "value=" + encodeURIComponent(value);
    }
  }
});

// Delayed observer, like Form.Element.Observer, 
// but waits for delay after last key input
// Ideal for live-search fields

Form.Element.DelayedObserver = Class.create();
Form.Element.DelayedObserver.prototype = {
  initialize: function(element, delay, callback) {
    this.delay     = delay || 0.5;
    this.element   = $(element);
    this.callback  = callback;
    this.timer     = null;
    this.lastValue = $F(this.element); 
    Event.observe(this.element,'keyup',this.delayedListener.bindAsEventListener(this));
  },
  delayedListener: function(event) {
    if(this.lastValue == $F(this.element)) return;
    if(this.timer) clearTimeout(this.timer);
    this.timer = setTimeout(this.onTimerEvent.bind(this), this.delay * 1000);
    this.lastValue = $F(this.element);
  },
  onTimerEvent: function() {
    this.timer = null;
    this.callback(this.element, $F(this.element));
  }
};