Knocout-Kendo custom binding for data bars

kendoDataBar.js

ko.bindingHandlers.kendoDataBar = {  
    init: function (element, valueAccessor, 
                    allBindingsAccessor, viewModel, bindingContext) {
        var data = ko.computed(function() {
            var field = ko.utils.unwrapObservable(valueAccessor().field),
                comparisons = ko.utils.unwrapObservable(valueAccessor().comparisons),
                numerator = 0,
                max = 0,
                sum = 0,
                values = [],
                result = { percentage: 0, value: 0 };

            if (field) { 
                numerator = parseFloat(ko.utils.unwrapObservable(valueAccessor().value[field]), 10);
                
                ko.utils.arrayForEach(comparisons, function(comparison) {
                    values.push(parseFloat(ko.utils.unwrapObservable(comparison[field]), 10));
                });
            } else {
                numerator = parseFloat(ko.utils.unwrapObservable(valueAccessor().value), 10); 
                
                ko.utils.arrayForEach(comparisons, function(comparison) {
                    values.push(parseFloat(ko.utils.unwrapObservable(comparison), 10));
                });
            }
            
            ko.utils.arrayForEach(values, function(value) {
                sum += value;
            });
    
            max = Math.max.apply(Math, values);

            if (max) {
                result.value = numerator/max;
            }
            
            if (sum) {
                result.percentage = numerator/sum;
            }
            
            return result;
        }),
            color = ko.utils.unwrapObservable(valueAccessor().color) || ko.bindingHandlers.kendoDataBar.defaultColor,
            template = ko.utils.unwrapObservable(valueAccessor().template) || ko.bindingHandlers.kendoDataBar.defaultTemplate,
            dataBar = ko.observable({ 
                data: [data],
                type: 'bar',
                valueAxis: { min: 0, max: 1 },
                series: [{ field: 'value', gap: 0, color: color }],
                tooltip: { template: template }
            });

        ko.bindingHandlers.kendoSparkline.init(element, dataBar, 
            allBindingsAccessor, viewModel, bindingContext);
    },
    defaultColor: 0,
    defaultTemplate: '#= kendo.format("{0:P}", dataItem.percentage) #'
};