Kendo树形表在插入操作之前进行检查

Question

I'm trying Kendo MVC treelist with popup editing using template.

Before inserting a record I'm doing some business rule checks at server-side. I return these errors from controller with "ModelState.ToDataSourceResult()".
If record does not meet requirements, I want to prevent insert operation.

But I could not be able to find event or property which handles this situation.

Grid has onReqestEnd event to catch results from controller but TreeList does -not.-

Answer 1

I found a solution for this requirement ,

Here is sample controller code :

    public ActionResult _Create([DataSourceRequest] DataSourceRequest request, Product product)
    {
        //Manually add an model error in order to simulate validation error
        ModelState.AddModelError("Name", "My server error");

        //TODO: implement create functionality

        return Json(ModelState.ToDataSourceResult());
    }

Telerik TreeListDataSource does not expose onRequestEnd event but it can be bound at document.ready :

 $(document).ready(function () {

        ds = $('#myTreeList').data('kendoTreeList').dataSource;
        ds.bind("requestEnd", onTreeListRequestEnd);

    });

I check operation type for ajax request end and call error handler function:

function onTreeListRequestEnd(e) {

    if (e.type == "create" || e.type == "destroy") {
        onTreeListError(e.response);
    }

}

Defined error message template :

<script type="text/kendo-template" id="message">
<div class="k-widget k-tooltip k-tooltip-validation k-invalid-msg field-validation-error" style="margin: 0.5em; display: block; " data-for="#=field#" data-valmsg-for="#=field#" id="#=field#_validationMessage">
    <span class="k-icon k-warning"> </span>#=message#<div class="k-callout k-callout-n"></div>
</div>
</script>

Displayed error message :

<script type="text/javascript">
var validationMessageTmpl = kendo.template($("#message").html());

function onTreeListError(args) {
    if (args.Errors) {
        var treeList = $("#myTreeList").data("kendoTreeList");
        treeList.one("dataBinding", function (e) {
            e.preventDefault();   // cancel treeList rebind if error occurs

            for (var error in args.Errors) {
                showMessage(treeList.editor.editable.element, error, args.Errors[error].errors);
            }
        });
    }
}

function showMessage(container, name, errors) {
    //add the validation message to the form
    //if multiple messages exists at ModelState concat them
    errMessage = "";
    for (var i = 0; i < errors.length; i++){
        errMessage = errMessage.concat("\r");
        errMessage = errMessage.concat(errors[i]);
    }
    container.find("[data-valmsg-for=" + name + "],[data-val-msg-for=" + name + "]")
                    .replaceWith(validationMessageTmpl({ field: name, message: errMessage }))
}
</script>

I got help from Telerik MVC Grid question : http://www.telerik.com/forums/kendo-grid-edit-mode-popup---error-handling

and this sample project : Handling server-side validation errors during pop-up editing

Hope this helps someone..

Answer 2

Thanks T10 for sharing your solution,
With your solution I can use it in Kendo TreeList MVC while creating a Kendo TreeList.

@(Html.Kendo().TreeList<YourModel>()
    .Name("TreeList")
    .DataSource(d=> d.Events(e => e.RequestEnd("onTreeListRequestEnd"))
)

Hope this can help someone.