jquery.form.js

文件是《精通Javascript+jQuery》的书中实例

};


/**
 * Serializes all field elements in the jQuery object into a query string.
 * This method will return a string in the format: name1=value1&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").fieldSerialize();
 * @desc Collect the data from all successful input elements into a query string
 *
 * @example var data = $(":radio").fieldSerialize();
 * @desc Collect the data from all successful radio input elements into a query string
 *
 * @example var data = $("#myForm :checkbox").fieldSerialize();
 * @desc Collect the data from all successful checkbox input elements in myForm into a query string
 *
 * @example var data = $("#myForm :checkbox").fieldSerialize(false);
 * @desc Collect the data from all checkbox elements in myForm (even the unchecked ones) into a query string
 *
 * @example var data = $(":input").fieldSerialize();
 * @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
 */
$.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.
 *
 * @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
 */
$.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.
 *
 * 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
 */
$.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 = $.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
 */
$.fn.clearForm = function() {
    return this.each(function() {
        $('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
 */
$.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.
 *
 * @example $('form').resetForm();
 * @desc Resets all forms on the page.
 *
 * @name resetForm
 * @type jQuery
 * @cat Plugins/Form
 */
$.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.
 *
 * @example $(':radio').enabled(false);
 * @desc Disables all radio buttons
 *
 * @name select
 * @type jQuery
 * @cat Plugins/Form
 */
$.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.
 *
 * @example $(':checkbox').select();
 * @desc Checks all checkboxes
 *
 * @name select
 * @type jQuery
 * @cat Plugins/Form
 */
$.fn.select = 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').select(false);
            }
            this.selected = select;
        }
    });
};

})(jQuery);