仅用于用户更改的kendo视图模型更改事件

Question

我有一个Kendo视图模型，我正在尝试检测页面上的用户更改，以便我可以警告他们，如果他们即将离开而不保存（使用onbeforeunload事件处理程序）。我绑定到视图模型更改事件以将“已更改”布尔值设置为true。但是，在document.ready完成之后，许多视图模型字段从其数据源异步加载，触发我无法区分用户更改的更改事件。有没有办法检测所有字段何时完成检索数据，以便我不会将其绑定更新误认为用户更改？

<script>
    var myViewModel = kendo.observable({
        someField: "testing",
        //...Other fields with data sources that get filled in asynchronously
        //Problem is that these are bound to fields in html and trigger change event
        changed: false,
        loading: false,
        fetch: function () {
            this.set("loading", true);
            //...
            this.set("loading", false);
        }
    });
</script>

<div id="myView">
    <input type="text" data-bind="value: someField" class="k-textbox" />
    <!--Other fields bound to fields in myViewModel-->
</div>

<script>
    $(document).ready(function () {
        myViewModel.fetch().then(function () {
            kendo.bind($("#myView"), myViewModel);
        }, function (error) {
        });
    });

    myViewModel.bind("change", function (e) {
        if (myViewModel.loading === false) {
            myViewModel.changed = true;
        }
    });

    window.onbeforeunload = function () {
        if (myViewModel.changed) {
            return "You haven't saved your changes!";
        }
    }
</script>