gistfile1.js

var sortingEngine = (function() {
       function dynamicSort(property) {
            var sortOrder = 1;
            if(property[0] === "-") {
                sortOrder = -1;
                property = property.substr(1);
            }
            return function (a,b) {
                var result = (a[property] < b[property]) ? -1 : (a[property] > b[property]) ? 1 : 0;
                return result * sortOrder;
            }
        }
 
        function dynamicSortMultiple(multiplySort) {
            /*
             * save the arguments object as it will be overwritten
             * note that arguments object is an array-like object
             * consisting of the names of the properties to sort by
             */
            var props = multiplySort;
            return function (obj1, obj2) {
                var i = 0, result = 0, numberOfProperties = props.length;
                /* try getting a different result from 0 (equal)
                 * as long as we have extra properties to compare
                 */
                while(result === 0 && i < numberOfProperties) {
                    result = dynamicSort(props[i])(obj1, obj2);
                    i++;
                }
                return result;
            }
        }
 
        return {
            dynamicSort: dynamicSort,
            dynamicSortMultiple: dynamicSortMultiple
        }
})();

sortingEngine.dynamicSort(smth);