jQuery-Form-Plugin für AJAXifizierung von Forms
authorMoritz Bunkus <m.bunkus@linet-services.de>
Mon, 27 Dec 2010 13:05:00 +0000 (14:05 +0100)
committerMoritz Bunkus <m.bunkus@linet-services.de>
Mon, 27 Dec 2010 13:05:00 +0000 (14:05 +0100)
js/jquery.form.js [new file with mode: 0644]

diff --git a/js/jquery.form.js b/js/jquery.form.js
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+/*!
+ * jQuery Form Plugin
+ * version: 2.52 (07-DEC-2010)
+ * @requires jQuery v1.3.2 or later
+ *
+ * Examples and documentation at: http://malsup.com/jquery/form/
+ * Dual licensed under the MIT and GPL licenses:
+ *   http://www.opensource.org/licenses/mit-license.php
+ *   http://www.gnu.org/licenses/gpl.html
+ */
+;(function($) {
+
+/*
+       Usage Note:
+       -----------
+       Do not use both ajaxSubmit and ajaxForm on the same form.  These
+       functions are intended to be exclusive.  Use ajaxSubmit if you want
+       to bind your own submit handler to the form.  For example,
+
+       $(document).ready(function() {
+               $('#myForm').bind('submit', function(e) {
+                       e.preventDefault(); // <-- important
+                       $(this).ajaxSubmit({
+                               target: '#output'
+                       });
+               });
+       });
+
+       Use ajaxForm when you want the plugin to manage all the event binding
+       for you.  For example,
+
+       $(document).ready(function() {
+               $('#myForm').ajaxForm({
+                       target: '#output'
+               });
+       });
+
+       When using ajaxForm, the ajaxSubmit function will be invoked for you
+       at the appropriate time.
+*/
+
+/**
+ * ajaxSubmit() provides a mechanism for immediately submitting
+ * an HTML form using AJAX.
+ */
+$.fn.ajaxSubmit = function(options) {
+       // fast fail if nothing selected (http://dev.jquery.com/ticket/2752)
+       if (!this.length) {
+               log('ajaxSubmit: skipping submit process - no element selected');
+               return this;
+       }
+
+       if (typeof options == 'function') {
+               options = { success: options };
+       }
+
+       var action = this.attr('action');
+       var url = (typeof action === 'string') ? $.trim(action) : '';
+       if (url) {
+               // clean url (don't include hash vaue)
+               url = (url.match(/^([^#]+)/)||[])[1];
+       }
+       url = url || window.location.href || '';
+
+       options = $.extend(true, {
+               url:  url,
+               type: this.attr('method') || 'GET',
+               iframeSrc: /^https/i.test(window.location.href || '') ? 'javascript:false' : 'about:blank'
+       }, options);
+
+       // hook for manipulating the form data before it is extracted;
+       // convenient for use with rich editors like tinyMCE or FCKEditor
+       var veto = {};
+       this.trigger('form-pre-serialize', [this, options, veto]);
+       if (veto.veto) {
+               log('ajaxSubmit: submit vetoed via form-pre-serialize trigger');
+               return this;
+       }
+
+       // provide opportunity to alter form data before it is serialized
+       if (options.beforeSerialize && options.beforeSerialize(this, options) === false) {
+               log('ajaxSubmit: submit aborted via beforeSerialize callback');
+               return this;
+       }
+
+       var n,v,a = this.formToArray(options.semantic);
+       if (options.data) {
+               options.extraData = options.data;
+               for (n in options.data) {
+                       if(options.data[n] instanceof Array) {
+                               for (var k in options.data[n]) {
+                                       a.push( { name: n, value: options.data[n][k] } );
+                               }
+                       }
+                       else {
+                               v = options.data[n];
+                               v = $.isFunction(v) ? v() : v; // if value is fn, invoke it
+                               a.push( { name: n, value: v } );
+                       }
+               }
+       }
+
+       // give pre-submit callback an opportunity to abort the submit
+       if (options.beforeSubmit && options.beforeSubmit(a, this, options) === false) {
+               log('ajaxSubmit: submit aborted via beforeSubmit callback');
+               return this;
+       }
+
+       // fire vetoable 'validate' event
+       this.trigger('form-submit-validate', [a, this, options, veto]);
+       if (veto.veto) {
+               log('ajaxSubmit: submit vetoed via form-submit-validate trigger');
+               return this;
+       }
+
+       var q = $.param(a);
+
+       if (options.type.toUpperCase() == 'GET') {
+               options.url += (options.url.indexOf('?') >= 0 ? '&' : '?') + q;
+               options.data = null;  // data is null for 'get'
+       }
+       else {
+               options.data = q; // data is the query string for 'post'
+       }
+
+       var $form = this, callbacks = [];
+       if (options.resetForm) {
+               callbacks.push(function() { $form.resetForm(); });
+       }
+       if (options.clearForm) {
+               callbacks.push(function() { $form.clearForm(); });
+       }
+
+       // perform a load on the target only if dataType is not provided
+       if (!options.dataType && options.target) {
+               var oldSuccess = options.success || function(){};
+               callbacks.push(function(data) {
+                       var fn = options.replaceTarget ? 'replaceWith' : 'html';
+                       $(options.target)[fn](data).each(oldSuccess, arguments);
+               });
+       }
+       else if (options.success) {
+               callbacks.push(options.success);
+       }
+
+       options.success = function(data, status, xhr) { // jQuery 1.4+ passes xhr as 3rd arg
+               var context = options.context || options;   // jQuery 1.4+ supports scope context 
+               for (var i=0, max=callbacks.length; i < max; i++) {
+                       callbacks[i].apply(context, [data, status, xhr || $form, $form]);
+               }
+       };
+
+       // are there files to upload?
+       var fileInputs = $('input:file', this).length > 0;
+       var mp = 'multipart/form-data';
+       var multipart = ($form.attr('enctype') == mp || $form.attr('encoding') == mp);
+
+       // options.iframe allows user to force iframe mode
+       // 06-NOV-09: now defaulting to iframe mode if file input is detected
+   if (options.iframe !== false && (fileInputs || options.iframe || multipart)) {
+          // hack to fix Safari hang (thanks to Tim Molendijk for this)
+          // see:  http://groups.google.com/group/jquery-dev/browse_thread/thread/36395b7ab510dd5d
+          if (options.closeKeepAlive) {
+                  $.get(options.closeKeepAlive, fileUpload);
+               }
+          else {
+                  fileUpload();
+               }
+   }
+   else {
+          $.ajax(options);
+   }
+
+       // fire 'notify' event
+       this.trigger('form-submit-notify', [this, options]);
+       return this;
+
+
+       // private function for handling file uploads (hat tip to YAHOO!)
+       function fileUpload() {
+               var form = $form[0];
+
+               if ($(':input[name=submit],:input[id=submit]', form).length) {
+                       // if there is an input with a name or id of 'submit' then we won't be
+                       // able to invoke the submit fn on the form (at least not x-browser)
+                       alert('Error: Form elements must not have name or id of "submit".');
+                       return;
+               }
+               
+               var s = $.extend(true, {}, $.ajaxSettings, options);
+               s.context = s.context || s;
+               var id = 'jqFormIO' + (new Date().getTime()), fn = '_'+id;
+               window[fn] = function() {
+                       var f = $io.data('form-plugin-onload');
+                       if (f) {
+                               f();
+                               window[fn] = undefined;
+                               try { delete window[fn]; } catch(e){}
+                       }
+               }
+               var $io = $('<iframe id="' + id + '" name="' + id + '" src="'+ s.iframeSrc +'" onload="window[\'_\'+this.id]()" />');
+               var io = $io[0];
+
+               $io.css({ position: 'absolute', top: '-1000px', left: '-1000px' });
+
+               var xhr = { // mock object
+                       aborted: 0,
+                       responseText: null,
+                       responseXML: null,
+                       status: 0,
+                       statusText: 'n/a',
+                       getAllResponseHeaders: function() {},
+                       getResponseHeader: function() {},
+                       setRequestHeader: function() {},
+                       abort: function() {
+                               this.aborted = 1;
+                               $io.attr('src', s.iframeSrc); // abort op in progress
+                       }
+               };
+
+               var g = s.global;
+               // trigger ajax global events so that activity/block indicators work like normal
+               if (g && ! $.active++) {
+                       $.event.trigger("ajaxStart");
+               }
+               if (g) {
+                       $.event.trigger("ajaxSend", [xhr, s]);
+               }
+
+               if (s.beforeSend && s.beforeSend.call(s.context, xhr, s) === false) {
+                       if (s.global) { 
+                               $.active--;
+                       }
+                       return;
+               }
+               if (xhr.aborted) {
+                       return;
+               }
+
+               var cbInvoked = false;
+               var timedOut = 0;
+
+               // add submitting element to data if we know it
+               var sub = form.clk;
+               if (sub) {
+                       var n = sub.name;
+                       if (n && !sub.disabled) {
+                               s.extraData = s.extraData || {};
+                               s.extraData[n] = sub.value;
+                               if (sub.type == "image") {
+                                       s.extraData[n+'.x'] = form.clk_x;
+                                       s.extraData[n+'.y'] = form.clk_y;
+                               }
+                       }
+               }
+
+               // take a breath so that pending repaints get some cpu time before the upload starts
+               function doSubmit() {
+                       // make sure form attrs are set
+                       var t = $form.attr('target'), a = $form.attr('action');
+
+                       // update form attrs in IE friendly way
+                       form.setAttribute('target',id);
+                       if (form.getAttribute('method') != 'POST') {
+                               form.setAttribute('method', 'POST');
+                       }
+                       if (form.getAttribute('action') != s.url) {
+                               form.setAttribute('action', s.url);
+                       }
+
+                       // ie borks in some cases when setting encoding
+                       if (! s.skipEncodingOverride) {
+                               $form.attr({
+                                       encoding: 'multipart/form-data',
+                                       enctype:  'multipart/form-data'
+                               });
+                       }
+
+                       // support timout
+                       if (s.timeout) {
+                               setTimeout(function() { timedOut = true; cb(); }, s.timeout);
+                       }
+
+                       // add "extra" data to form if provided in options
+                       var extraInputs = [];
+                       try {
+                               if (s.extraData) {
+                                       for (var n in s.extraData) {
+                                               extraInputs.push(
+                                                       $('<input type="hidden" name="'+n+'" value="'+s.extraData[n]+'" />')
+                                                               .appendTo(form)[0]);
+                                       }
+                               }
+
+                               // add iframe to doc and submit the form
+                               $io.appendTo('body');
+                               $io.data('form-plugin-onload', cb);
+                               form.submit();
+                       }
+                       finally {
+                               // reset attrs and remove "extra" input elements
+                               form.setAttribute('action',a);
+                               if(t) {
+                                       form.setAttribute('target', t);
+                               } else {
+                                       $form.removeAttr('target');
+                               }
+                               $(extraInputs).remove();
+                       }
+               }
+
+               if (s.forceSync) {
+                       doSubmit();
+               }
+               else {
+                       setTimeout(doSubmit, 10); // this lets dom updates render
+               }
+       
+               var data, doc, domCheckCount = 50;
+
+               function cb() {
+                       if (cbInvoked) {
+                               return;
+                       }
+
+                       $io.removeData('form-plugin-onload');
+                       
+                       var ok = true;
+                       try {
+                               if (timedOut) {
+                                       throw 'timeout';
+                               }
+                               // extract the server response from the iframe
+                               doc = io.contentWindow ? io.contentWindow.document : io.contentDocument ? io.contentDocument : io.document;
+                               
+                               var isXml = s.dataType == 'xml' || doc.XMLDocument || $.isXMLDoc(doc);
+                               log('isXml='+isXml);
+                               if (!isXml && window.opera && (doc.body == null || doc.body.innerHTML == '')) {
+                                       if (--domCheckCount) {
+                                               // in some browsers (Opera) the iframe DOM is not always traversable when
+                                               // the onload callback fires, so we loop a bit to accommodate
+                                               log('requeing onLoad callback, DOM not available');
+                                               setTimeout(cb, 250);
+                                               return;
+                                       }
+                                       // let this fall through because server response could be an empty document
+                                       //log('Could not access iframe DOM after mutiple tries.');
+                                       //throw 'DOMException: not available';
+                               }
+
+                               //log('response detected');
+                               cbInvoked = true;
+                               xhr.responseText = doc.documentElement ? doc.documentElement.innerHTML : null; 
+                               xhr.responseXML = doc.XMLDocument ? doc.XMLDocument : doc;
+                               xhr.getResponseHeader = function(header){
+                                       var headers = {'content-type': s.dataType};
+                                       return headers[header];
+                               };
+
+                               var scr = /(json|script)/.test(s.dataType);
+                               if (scr || s.textarea) {
+                                       // see if user embedded response in textarea
+                                       var ta = doc.getElementsByTagName('textarea')[0];
+                                       if (ta) {
+                                               xhr.responseText = ta.value;
+                                       }
+                                       else if (scr) {
+                                               // account for browsers injecting pre around json response
+                                               var pre = doc.getElementsByTagName('pre')[0];
+                                               var b = doc.getElementsByTagName('body')[0];
+                                               if (pre) {
+                                                       xhr.responseText = pre.textContent;
+                                               }
+                                               else if (b) {
+                                                       xhr.responseText = b.innerHTML;
+                                               }
+                                       }                         
+                               }
+                               else if (s.dataType == 'xml' && !xhr.responseXML && xhr.responseText != null) {
+                                       xhr.responseXML = toXml(xhr.responseText);
+                               }
+                               data = $.httpData(xhr, s.dataType);
+                       }
+                       catch(e){
+                               log('error caught:',e);
+                               ok = false;
+                               xhr.error = e;
+                               $.handleError(s, xhr, 'error', e);
+                       }
+                       
+                       if (xhr.aborted) {
+                               log('upload aborted');
+                               ok = false;
+                       }
+
+                       // ordering of these callbacks/triggers is odd, but that's how $.ajax does it
+                       if (ok) {
+                               s.success.call(s.context, data, 'success', xhr);
+                               if (g) {
+                                       $.event.trigger("ajaxSuccess", [xhr, s]);
+                               }
+                       }
+                       if (g) {
+                               $.event.trigger("ajaxComplete", [xhr, s]);
+                       }
+                       if (g && ! --$.active) {
+                               $.event.trigger("ajaxStop");
+                       }
+                       if (s.complete) {
+                               s.complete.call(s.context, xhr, ok ? 'success' : 'error');
+                       }
+
+                       // clean up
+                       setTimeout(function() {
+                               $io.removeData('form-plugin-onload');
+                               $io.remove();
+                               xhr.responseXML = null;
+                       }, 100);
+               }
+
+               function toXml(s, doc) {
+                       if (window.ActiveXObject) {
+                               doc = new ActiveXObject('Microsoft.XMLDOM');
+                               doc.async = 'false';
+                               doc.loadXML(s);
+                       }
+                       else {
+                               doc = (new DOMParser()).parseFromString(s, 'text/xml');
+                       }
+                       return (doc && doc.documentElement && doc.documentElement.tagName != 'parsererror') ? doc : null;
+               }
+       }
+};
+
+/**
+ * ajaxForm() provides a mechanism for fully automating form submission.
+ *
+ * The advantages of using this method instead of ajaxSubmit() are:
+ *
+ * 1: This method will include coordinates for <input type="image" /> elements (if the element
+ *     is used to submit the form).
+ * 2. This method will include the submit element's name/value data (for the element that was
+ *     used to submit the form).
+ * 3. This method binds the submit() method to the form for you.
+ *
+ * The options argument for ajaxForm works exactly as it does for ajaxSubmit.  ajaxForm merely
+ * passes the options argument along after properly binding events for submit elements and
+ * the form itself.
+ */
+$.fn.ajaxForm = function(options) {
+       // in jQuery 1.3+ we can fix mistakes with the ready state
+       if (this.length === 0) {
+               var o = { s: this.selector, c: this.context };
+               if (!$.isReady && o.s) {
+                       log('DOM not ready, queuing ajaxForm');
+                       $(function() {
+                               $(o.s,o.c).ajaxForm(options);
+                       });
+                       return this;
+               }
+               // is your DOM ready?  http://docs.jquery.com/Tutorials:Introducing_$(document).ready()
+               log('terminating; zero elements found by selector' + ($.isReady ? '' : ' (DOM not ready)'));
+               return this;
+       }
+       
+       return this.ajaxFormUnbind().bind('submit.form-plugin', function(e) {
+               if (!e.isDefaultPrevented()) { // if event has been canceled, don't proceed
+                       e.preventDefault();
+                       $(this).ajaxSubmit(options);
+               }
+       }).bind('click.form-plugin', function(e) {
+               var target = e.target;
+               var $el = $(target);
+               if (!($el.is(":submit,input:image"))) {
+                       // is this a child element of the submit el?  (ex: a span within a button)
+                       var t = $el.closest(':submit');
+                       if (t.length == 0) {
+                               return;
+                       }
+                       target = t[0];
+               }
+               var form = this;
+               form.clk = target;
+               if (target.type == 'image') {
+                       if (e.offsetX != undefined) {
+                               form.clk_x = e.offsetX;
+                               form.clk_y = e.offsetY;
+                       } else if (typeof $.fn.offset == 'function') { // try to use dimensions plugin
+                               var offset = $el.offset();
+                               form.clk_x = e.pageX - offset.left;
+                               form.clk_y = e.pageY - offset.top;
+                       } else {
+                               form.clk_x = e.pageX - target.offsetLeft;
+                               form.clk_y = e.pageY - target.offsetTop;
+                       }
+               }
+               // clear form vars
+               setTimeout(function() { form.clk = form.clk_x = form.clk_y = null; }, 100);
+       });
+};
+
+// ajaxFormUnbind unbinds the event handlers that were bound by ajaxForm
+$.fn.ajaxFormUnbind = function() {
+       return this.unbind('submit.form-plugin click.form-plugin');
+};
+
+/**
+ * formToArray() gathers form element data into an array of objects that can
+ * be passed to any of the following ajax functions: $.get, $.post, or load.
+ * Each object in the array has both a 'name' and 'value' property.  An example of
+ * an array for a simple login form might be:
+ *
+ * [ { name: 'username', value: 'jresig' }, { name: 'password', value: 'secret' } ]
+ *
+ * It is this array that is passed to pre-submit callback functions provided to the
+ * ajaxSubmit() and ajaxForm() methods.
+ */
+$.fn.formToArray = function(semantic) {
+       var a = [];
+       if (this.length === 0) {
+               return a;
+       }
+
+       var form = this[0];
+       var els = semantic ? form.getElementsByTagName('*') : form.elements;
+       if (!els) {
+               return a;
+       }
+       
+       var i,j,n,v,el,max,jmax;
+       for(i=0, max=els.length; i < max; i++) {
+               el = els[i];
+               n = el.name;
+               if (!n) {
+                       continue;
+               }
+
+               if (semantic && form.clk && el.type == "image") {
+                       // handle image inputs on the fly when semantic == true
+                       if(!el.disabled && form.clk == el) {
+                               a.push({name: n, value: $(el).val()});
+                               a.push({name: n+'.x', value: form.clk_x}, {name: n+'.y', value: form.clk_y});
+                       }
+                       continue;
+               }
+
+               v = $.fieldValue(el, true);
+               if (v && v.constructor == Array) {
+                       for(j=0, jmax=v.length; j < jmax; j++) {
+                               a.push({name: n, value: v[j]});
+                       }
+               }
+               else if (v !== null && typeof v != 'undefined') {
+                       a.push({name: n, value: v});
+               }
+       }
+
+       if (!semantic && form.clk) {
+               // input type=='image' are not found in elements array! handle it here
+               var $input = $(form.clk), input = $input[0];
+               n = input.name;
+               if (n && !input.disabled && input.type == 'image') {
+                       a.push({name: n, value: $input.val()});
+                       a.push({name: n+'.x', value: form.clk_x}, {name: n+'.y', value: form.clk_y});
+               }
+       }
+       return a;
+};
+
+/**
+ * Serializes form data into a 'submittable' string. This method will return a string
+ * in the format: name1=value1&amp;name2=value2
+ */
+$.fn.formSerialize = function(semantic) {
+       //hand off to jQuery.param for proper encoding
+       return $.param(this.formToArray(semantic));
+};
+
+/**
+ * Serializes all field elements in the jQuery object into a query string.
+ * This method will return a string in the format: name1=value1&amp;name2=value2
+ */
+$.fn.fieldSerialize = function(successful) {
+       var a = [];
+       this.each(function() {
+               var n = this.name;
+               if (!n) {
+                       return;
+               }
+               var v = $.fieldValue(this, successful);
+               if (v && v.constructor == Array) {
+                       for (var i=0,max=v.length; i < max; i++) {
+                               a.push({name: n, value: v[i]});
+                       }
+               }
+               else if (v !== null && typeof v != 'undefined') {
+                       a.push({name: this.name, value: v});
+               }
+       });
+       //hand off to jQuery.param for proper encoding
+       return $.param(a);
+};
+
+/**
+ * Returns the value(s) of the element in the matched set.  For example, consider the following form:
+ *
+ *  <form><fieldset>
+ *       <input name="A" type="text" />
+ *       <input name="A" type="text" />
+ *       <input name="B" type="checkbox" value="B1" />
+ *       <input name="B" type="checkbox" value="B2"/>
+ *       <input name="C" type="radio" value="C1" />
+ *       <input name="C" type="radio" value="C2" />
+ *  </fieldset></form>
+ *
+ *  var v = $(':text').fieldValue();
+ *  // if no values are entered into the text inputs
+ *  v == ['','']
+ *  // if values entered into the text inputs are 'foo' and 'bar'
+ *  v == ['foo','bar']
+ *
+ *  var v = $(':checkbox').fieldValue();
+ *  // if neither checkbox is checked
+ *  v === undefined
+ *  // if both checkboxes are checked
+ *  v == ['B1', 'B2']
+ *
+ *  var v = $(':radio').fieldValue();
+ *  // if neither radio is checked
+ *  v === undefined
+ *  // if first radio is checked
+ *  v == ['C1']
+ *
+ * The successful argument controls whether or not the field element must be 'successful'
+ * (per http://www.w3.org/TR/html4/interact/forms.html#successful-controls).
+ * The default value of the successful argument is true.  If this value is false the value(s)
+ * for each element is returned.
+ *
+ * Note: This method *always* returns an array.  If no valid value can be determined the
+ *        array will be empty, otherwise it will contain one or more values.
+ */
+$.fn.fieldValue = function(successful) {
+       for (var val=[], i=0, max=this.length; i < max; i++) {
+               var el = this[i];
+               var v = $.fieldValue(el, successful);
+               if (v === null || typeof v == 'undefined' || (v.constructor == Array && !v.length)) {
+                       continue;
+               }
+               v.constructor == Array ? $.merge(val, v) : val.push(v);
+       }
+       return val;
+};
+
+/**
+ * Returns the value of the field element.
+ */
+$.fieldValue = function(el, successful) {
+       var n = el.name, t = el.type, tag = el.tagName.toLowerCase();
+       if (successful === undefined) {
+               successful = true;
+       }
+
+       if (successful && (!n || el.disabled || t == 'reset' || t == 'button' ||
+               (t == 'checkbox' || t == 'radio') && !el.checked ||
+               (t == 'submit' || t == 'image') && el.form && el.form.clk != el ||
+               tag == 'select' && el.selectedIndex == -1)) {
+                       return null;
+       }
+
+       if (tag == 'select') {
+               var index = el.selectedIndex;
+               if (index < 0) {
+                       return null;
+               }
+               var a = [], ops = el.options;
+               var one = (t == 'select-one');
+               var max = (one ? index+1 : ops.length);
+               for(var i=(one ? index : 0); i < max; i++) {
+                       var op = ops[i];
+                       if (op.selected) {
+                               var v = op.value;
+                               if (!v) { // extra pain for IE...
+                                       v = (op.attributes && op.attributes['value'] && !(op.attributes['value'].specified)) ? op.text : op.value;
+                               }
+                               if (one) {
+                                       return v;
+                               }
+                               a.push(v);
+                       }
+               }
+               return a;
+       }
+       return $(el).val();
+};
+
+/**
+ * Clears the form data.  Takes the following actions on the form's input fields:
+ *  - input text fields will have their 'value' property set to the empty string
+ *  - select elements will have their 'selectedIndex' property set to -1
+ *  - checkbox and radio inputs will have their 'checked' property set to false
+ *  - inputs of type submit, button, reset, and hidden will *not* be effected
+ *  - button elements will *not* be effected
+ */
+$.fn.clearForm = function() {
+       return this.each(function() {
+               $('input,select,textarea', this).clearFields();
+       });
+};
+
+/**
+ * Clears the selected form elements.
+ */
+$.fn.clearFields = $.fn.clearInputs = function() {
+       return this.each(function() {
+               var t = this.type, tag = this.tagName.toLowerCase();
+               if (t == 'text' || t == 'password' || tag == 'textarea') {
+                       this.value = '';
+               }
+               else if (t == 'checkbox' || t == 'radio') {
+                       this.checked = false;
+               }
+               else if (tag == 'select') {
+                       this.selectedIndex = -1;
+               }
+       });
+};
+
+/**
+ * Resets the form data.  Causes all form elements to be reset to their original value.
+ */
+$.fn.resetForm = function() {
+       return this.each(function() {
+               // guard against an input with the name of 'reset'
+               // note that IE reports the reset function as an 'object'
+               if (typeof this.reset == 'function' || (typeof this.reset == 'object' && !this.reset.nodeType)) {
+                       this.reset();
+               }
+       });
+};
+
+/**
+ * Enables or disables any matching elements.
+ */
+$.fn.enable = function(b) {
+       if (b === undefined) {
+               b = true;
+       }
+       return this.each(function() {
+               this.disabled = !b;
+       });
+};
+
+/**
+ * Checks/unchecks any matching checkboxes or radio buttons and
+ * selects/deselects and matching option elements.
+ */
+$.fn.selected = function(select) {
+       if (select === undefined) {
+               select = true;
+       }
+       return this.each(function() {
+               var t = this.type;
+               if (t == 'checkbox' || t == 'radio') {
+                       this.checked = select;
+               }
+               else if (this.tagName.toLowerCase() == 'option') {
+                       var $sel = $(this).parent('select');
+                       if (select && $sel[0] && $sel[0].type == 'select-one') {
+                               // deselect all other options
+                               $sel.find('option').selected(false);
+                       }
+                       this.selected = select;
+               }
+       });
+};
+
+// helper fn for console logging
+// set $.fn.ajaxSubmit.debug to true to enable debug logging
+function log() {
+       if ($.fn.ajaxSubmit.debug) {
+               var msg = '[jquery.form] ' + Array.prototype.join.call(arguments,'');
+               if (window.console && window.console.log) {
+                       window.console.log(msg);
+               }
+               else if (window.opera && window.opera.postError) {
+                       window.opera.postError(msg);
+               }
+       }
+};
+
+})(jQuery);