MVVM binding for cascading DropDownList

问题:

I have a web page with two kendoDropDownList using cascading. The first are States and the second Cities. When you choose a State then you are able the City to choose from the second DropDownList. This works perfectly well if I pick them using the mouse.

The problem is when I try to bind some data to these DropDownLists where the State is updated but not the City.

This is the HTML of my page:

<div id="container">
    <input id="state" name="state" data-bind="value: state"/>
    <input id="city" name="city" data-bind="value: city"/>
</div>

And this is the JavaScript:

var state = $("#state").kendoDropDownList({
    dataTextField: "state",
    dataValueField:"state",
    dataSource:    {
        serverFiltering:true,
        data:           states
    },
    change:        function () {
        console.log("state changed");
    }
}).data("kendoDropDownList");

var city = $("#city").kendoDropDownList({
    autoBind:      false,
    dataTextField: "city",
    dataValueField:"city",
    cascadeFrom:   "state",
    dataSource:    {
        serverFiltering:true,
        transport:      {
            read:function (operation) {
                var ds = cities [state.value()];
                if (ds) {
                    return operation.success(ds);
                } else {
                    return operation.success(["N/A"]);
                }
            }
        }
    }
}).data("kendoDropDownList");

If I use the following code for binding the data:

kendo.bind($("#container"), { state:"California", city: "Berkeley" });

Unless State DropDownList already contains the value California it will not set city to Berkeley.

Seems that using bind does not trigger a change event in States DropDownList and then City DropDownList is not reloaded with the Cities of the new State.

You can find this code in http://jsfiddle.net/OnaBai/QUhEX/3/

How should I use cascading with MVVM binding?

回答1:

I've prepared a demo showing how to use cascading dropdownlists with MVVM: http://jsbin.com/ujorer/1/edit