Javascript: Prototype Pattern (xmlencode, convert to ISO date, json object length, create object from sharepoint responseXML)

Javascript: Prototype Pattern (xmlencode, convert to ISO date, json object length, create object from sharepoint responseXML)

/* sample for prototype pattern, xmlencode, convertToISODate, get the length of a json object, create json object from sharepoint responseXML */

var Utilities = function() {
    
};

Utilities.prototype = {

    xmlencode : function (string) {    
        //encode the special character to make sure the caml request works
        return string.replace(/\&/g,'&'+'amp;').replace(/</g,'&'+'lt;').replace(/>/g,'&'+'gt;').replace(/\'/g,'&'+'apos;').replace(/\"/g,'&'+'quot;'); 
    }, 

    convertToISODate : function( date ) {
       
        //sharepoint date field only accept ISODate format  date should be javascript date format: mm/dd/yyyy
        date = date || new Date();

        function pad( n ) {
            return n < 10 ? '0' + n : n;
        }

        return  date.getFullYear() + '-' +
                pad( date.getMonth() + 1 ) + '-' +
                pad( date.getDate() ) + 'T' +
                pad( date.getHours() ) + ':' +
                pad( date.getMinutes() )+ ':' +
                pad( date.getSeconds() )+ 'Z';
    },

    objLength : function(obj){    
        var key,len=0;
        for(key in obj){
            len += Number( obj.hasOwnProperty(key) );
        }
        return len;
    },

    createJsonObjects : function (responseXML, columnMapping)
    {
        var results = [];
        var jsonObject = {};
        responseXML.SPFilterNode("z:row").each(function (itemNum){
            var $th = $(this);

            jsonObject ={};
            for (var prop in columnMapping) {
                if (columnMapping.hasOwnProperty(prop) && $th.attr(columnMapping[prop]) !== undefined)  {

                    if (prop.indexOf("Date") > 0)
                    {
                        var auDateFormat = $th.attr(columnMapping[prop]).replace( /(\d{4})-(\d{2})-(\d{2})/, "$3/$2/$1");

                        jsonObject[prop] = auDateFormat.substring(0,auDateFormat.indexOf(" ")+ 1);
                    }
                    else
                    {
                        jsonObject[prop] = $th.attr(columnMapping[prop]).indexOf("#") > 0 ? $th.attr(columnMapping[prop]).substring($th.attr(columnMapping[prop]).indexOf("#") + 1): $th.attr(columnMapping[prop]).replace(/\.0000.*/g, "");                        
                    }
                }
            }
            results.push (jsonObject);
        });
        return results;
    }, // end function

    replaceHtmlControl : function(controlId, itemArray) {
        //Replace the OPTIONS of an existing SELECT control         
        if (itemArray.length > 0) {
            $("#" + controlId).find("option").remove();
        }

        $.each(itemArray, function(i, item){
             $("#" + controlId).append($('<option>', { 
                                "data-spID": item.ID,
                                value: encodeURIComponent(item.Title),
                                text : item.Title 
             }));
        });
    }
}