form.js

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 * $('#myForm').ajaxSubmit(options);
 * @desc Bind form's submit event so that server response is alerted after the form is submitted.
 *
 *
 * @example
 * var options = {
 *     beforeSubmit: function(formArray, jqForm) {
 *         if (formArray.length == 0) {
 *             alert('Please enter data.');
 *             return false;
 *         }
 *     }
 * };
 * $('#myForm').ajaxSubmit(options);
 * @desc Bind form's submit event so that pre-submit callback is invoked before the form
 *       is submitted.
 *
 *
 * @name   ajaxForm
 * @param  options  object literal containing options which control the form submission process
 * @return jQuery
 * @cat    Plugins/Form
 * @type   jQuery
 * @see    ajaxSubmit
 * @author jQuery Community
 */
jQuery.fn.ajaxForm = function(options) {
    return this.each(function() {
        jQuery("input:submit,input:image,button:submit", this).click(function(ev) {
            var $form = this.form;
            $form.clk = this;
            if (this.type == 'image') {
                if (ev.offsetX != undefined) {
                    $form.clk_x = ev.offsetX;
                    $form.clk_y = ev.offsetY;
                } else if (typeof jQuery.fn.offset == 'function') { // try to use dimensions plugin
                    var offset = jQuery(this).offset();
                    $form.clk_x = ev.pageX - offset.left;
                    $form.clk_y = ev.pageY - offset.top;
                } else {
                    $form.clk_x = ev.pageX - this.offsetLeft;
                    $form.clk_y = ev.pageY - this.offsetTop;
                }
            }
            // clear form vars
            setTimeout(function() {
                $form.clk = $form.clk_x = $form.clk_y = null;
                }, 10);
        })
    }).submit(function(e) {
        jQuery(this).ajaxSubmit(options);
        return false;
    });
};


/**
 * 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.
 *
 * The semantic argument can be used to force form serialization in semantic order.
 * This is normally true anyway, unless the form contains input elements of type='image'.
 * If your form must be submitted with name/value pairs in semantic order and your form
 * contains an input of type='image" then pass true for this arg, otherwise pass false
 * (or nothing) to avoid the overhead for this logic.
 *
 * @example var data = $("#myForm").formToArray();
 * $.post( "myscript.cgi", data );
 * @desc Collect all the data from a form and submit it to the server.
 *
 * @name formToArray
 * @param semantic true if serialization must maintain strict semantic ordering of elements (slower)
 * @type Array<Object>
 * @cat Plugins/Form
 * @see ajaxForm
 * @see ajaxSubmit
 * @author jQuery Community
 */
jQuery.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;
    for(var i=0, max=els.length; i < max; i++) {
        var el = els[i];
        var 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+'.x', value: form.clk_x}, {name: n+'.y', value: form.clk_y});
            continue;
        }
        var v = jQuery.fieldValue(el, true);
        if (v === null) continue;
        if (v.constructor == Array) {
            for(var j=0, jmax=v.length; j < jmax; j++)
                a.push({name: n, value: v[j]});
        }
        else
            a.push({name: n, value: v});
    }

    if (!semantic && form.clk) {
        // input type=='image' are not found in elements array! handle them here
        var inputs = form.getElementsByTagName("input");
        for(var i=0, max=inputs.length; i < max; i++) {
            var input = inputs[i];
            var n = input.name;
            if(n && !input.disabled && input.type == "image" && form.clk == input)
                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
 *
 * The semantic argument can be used to force form serialization in semantic order.
 * If your form must be submitted with name/value pairs in semantic order then pass
 * true for this arg, otherwise pass false (or nothing) to avoid the overhead for
 * this logic (which can be significant for very large forms).
 *
 * @example var data = $("#myForm").formSerialize();
 * $.ajax('POST', "myscript.cgi", data);
 * @desc Collect all the data from a form into a single string
 *
 * @name formSerialize
 * @param semantic true if serialization must maintain strict semantic ordering of elements (slower)
 * @type String
 * @cat Plugins/Form
 * @see formToArray
 * @author jQuery Community
 */
jQuery.fn.formSerialize = function(semantic) {
    //hand off to jQuery.param for proper encoding
    return jQuery.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
 *
 * The successful argument controls whether or not serialization is limited to
 * 'successful' controls (per http://www.w3.org/TR/html4/interact/forms.html#successful-controls).
 * The default value of the successful argument is true.
 *
 * @example var data = $("input").formSerialize();
 * @desc Collect the data from all successful input elements into a query string
 *
 * @example var data = $(":radio").formSerialize();
 * @desc Collect the data from all successful radio input elements into a query string
 *
 * @example var data = $("#myForm :checkbox").formSerialize();
 * @desc Collect the data from all successful checkbox input elements in myForm into a query string
 *
 * @example var data = $("#myForm :checkbox").formSerialize(false);
 * @desc Collect the data from all checkbox elements in myForm (even the unchecked ones) into a query string
 *
 * @example var data = $(":input").formSerialize();
 * @desc Collect the data from all successful input, select, textarea and button elements into a query string
 *
 * @name fieldSerialize
 * @param successful true if only successful controls should be serialized (default is true)
 * @type String
 * @cat Plugins/Form
 */
jQuery.fn.fieldSerialize = function(successful) {
    var a = [];
    this.each(function() {
        var n = this.name;
        if (!n) return;
        var v = jQuery.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 jQuery.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.
 *
 * @example var data = $("#myPasswordElement").fieldValue();
 * alert(data[0]);
 * @desc Alerts the current value of the myPasswordElement element
 *
 * @example var data = $("#myForm :input").fieldValue();
 * @desc Get the value(s) of the form elements in myForm
 *
 * @example var data = $("#myForm :checkbox").fieldValue();
 * @desc Get the value(s) for the successful checkbox element(s) in the jQuery object.
 *
 * @example var data = $("#mySingleSelect").fieldValue();
 * @desc Get the value(s) of the select control
 *
 * @example var data = $(':text').fieldValue();
 * @desc Get the value(s) of the text input or textarea elements
 *
 * @example var data = $("#myMultiSelect").fieldValue();
 * @desc Get the values for the select-multiple control
 *
 * @name fieldValue
 * @param Boolean successful true if only the values for successful controls should be returned (default is true)
 * @type Array<String>
 * @cat Plugins/Form
 */
jQuery.fn.fieldValue = function(successful) {
    for (var val=[], i=0, max=this.length; i < max; i++) {
        var el = this[i];
        var v = jQuery.fieldValue(el, successful);
        if (v === null || typeof v == 'undefined' || (v.constructor == Array && !v.length))
            continue;
        v.constructor == Array ? jQuery.merge(val, v) : val.push(v);
    }
    return val;
};

/**
 * Returns the value of the field element.
 *
 * 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 the given element is not
 * successful and the successful arg is not false then the returned value will be null.
 *
 * Note: If the successful flag is true (default) but the element is not successful, the return will be null
 * Note: The value returned for a successful select-multiple element will always be an array.
 * Note: If the element has no value the return value will be undefined.
 *
 * @example var data = jQuery.fieldValue($("#myPasswordElement")[0]);
 * @desc Gets the current value of the myPasswordElement element
 *
 * @name fieldValue
 * @param Element el The DOM element for which the value will be returned
 * @param Boolean successful true if value returned must be for a successful controls (default is true)
 * @type String or Array<String> or null or undefined
 * @cat Plugins/Form
 */
jQuery.fieldValue = function(el, successful) {
    var n = el.name, t = el.type, tag = el.tagName.toLowerCase();
    if (typeof 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) {
                // extra pain for IE...
                var v = jQuery.browser.msie && !(op.attributes['value'].specified) ? op.text : op.value;
                if (one) return v;
                a.push(v);
            }
        }
        return a;
    }
    return el.value;
};


/**
 * 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
 *
 * @example $('form').clearForm();
 * @desc Clears all forms on the page.
 *
 * @name clearForm
 * @type jQuery
 * @cat Plugins/Form
 * @see resetForm
 */
jQuery.fn.clearForm = function() {
    return this.each(function() {
        jQuery('input,select,textarea', this).clearFields();
    });
};

/**
 * Clears the selected form elements.  Takes the following actions on the matched elements:
 *  - 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
 *
 * @example $('.myInputs').clearFields();
 * @desc Clears all inputs with class myInputs
 *
 * @name clearFields
 * @type jQuery
 * @cat Plugins/Form
 * @see clearForm
 */
jQuery.fn.clearFields = jQuery.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.
 *
 * @example $('form').resetForm();
 * @desc Resets all forms on the page.
 *
 * @name resetForm
 * @type jQuery
 * @cat Plugins/Form
 * @see clearForm
 */
jQuery.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();
    });
};