Question

I think I can easily bind a date data with jquery ui calendar and knockout.js thanks to this answer.

Now I need to bind a date data as well as its time. Of course, I can use timepicker. But I am not sure how I can bind its data with knockout.js. I expected it’d be similar to datepicker so I made following script

    ko.bindingHandlers.datetimepicker = {
        init: function (element, valueAccessor, allBindingsAccessor) {
            //initialize datepicker with some optional options
            var options = allBindingsAccessor().datetimepickerOptions || {};
            $(element).datetimepicker(options);

            //handle the field changing
            ko.utils.registerEventHandler(element, "change", function () {
                var observable = valueAccessor();
                observable($(element).datetimepicker("getDate"));//****
            });

            //handle disposal (if KO removes by the template binding)
            ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
                $(element).datetimepicker("destroy");
            });

        },
        update: function (element, valueAccessor) {
            var value = ko.utils.unwrapObservable(valueAccessor()),
                current = $(element).datetimepicker("getDate");

            if (value - current !== 0) {
                $(element).datetimepicker("setDate", value);
            }
        }
    };

But when I ran the script, I get an error in line of //**** in javascript

TypeError: observable is not a function

But I can’t find what I did wrong here.

Answer 1

I just found following code is working. As few open source code do, this addon is not very stable and will call change event with null observable sometimes. So I made the code to catch the exception and move on.

    ko.bindingHandlers.datetimepicker = {
        init: function (element, valueAccessor, allBindingsAccessor) {
            //initialize datepicker with some optional options
            var options = allBindingsAccessor().datetimepickerOptions || {};
            $(element).datetimepicker(options);

            //handle the field changing
            ko.utils.registerEventHandler(element, "change", function () {
                var observable = valueAccessor();
                try {
                    observable($(element).datetimepicker("getDate"));//****
                }
                catch(ex) {}
            });

            //handle disposal (if KO removes by the template binding)
            ko.utils.domNodeDisposal.addDisposeCallback(element, function () {
                $(element).datetimepicker("destroy");
            });

        },
        update: function (element, valueAccessor) {
            var value = ko.utils.unwrapObservable(valueAccessor()),
                current = $(element).datetimepicker("getDate");

            if (value - current !== 0) {
                $(element).datetimepicker("setDate", value);
            }
        }
    };