Kendo Grid model with an IEnumerable property not updating correctly after Create/Update when using AJAX binding

Question

I'm having a problem where a property of my model is not being correctly updated when sending it to my controller for an Update or Create call from a Kendo Grid. The model looks like this:

public class ReleaseNotesModel
{
    public int NoteID { get; set; }
    public int ReleaseID { get; set; }
    public List<TranslationModel> ReleaseNoteTranslations { get; set; }
    public ReleaseNoteType ItemType { get; set; }
}
public class TranslationModel
{
    public int TranslationID { get; set; }
    public string Translation { get; set; }
    public int LanguageID { get; set; }
    public int ItemID { get; set; }
}

Here is the grid in my view:

@(Html.Kendo().Grid<ReleaseNotesModel>()
    .Name("Grid")
    .Columns(columns =>
    {
        columns.Bound(m => m.ItemType).Width(140);
        columns.Bound(m => m.Description);
        columns.Command(command =>
            {
                command.Edit();
                command.Destroy();
            }).Width(170);
    })
    .ToolBar(toolbar => toolbar.Create())
    .Editable(editable => editable
        .Mode(GridEditMode.PopUp)
        .TemplateName("ReleaseNoteTemplate")
        .Window(w => w.Width(620))
        .DisplayDeleteConfirmation(true)
    )
    .Pageable()
    .Sortable()
    .Scrollable()
    .Filterable()
    .DataSource(dataSource => dataSource
        .Ajax()
        .ServerOperation(false)
        //.Server()
        .Events(e => e.Error("grid_error"))
        .Model(model =>
        {
            model.Id(m => m.NoteID);
            model.Field(m => m.ReleaseID).DefaultValue(Model.ReleaseID);
            model.Field(m => m.ItemType).DefaultValue(ReleaseNoteType.NewFeature);
            //defaultTranslationsList is a List<TranslationModel> with two empty objects in it
            model.Field(m => m.ReleaseNoteTranslations).DefaultValue(defaultTranslationsList);
        })
        .PageSize(5)
        .Read(read => read.Action("GetNotes", "ReleaseNotes", new { releaseID = Model.ReleaseID }))
        .Create(create => create.Action("AddNote", "ReleaseNotes"))
        .Update(update => update.Action("EditNote", "ReleaseNotes"))
        .Destroy(destroy => destroy.Action("DeleteNote", "ReleaseNotes"))
    )
)

So more specifically, the problem I am having is that in my controller action:

public async Task<ActionResult> EditNote(ReleaseNotesModel model)

model.ReleaseNoteTranslations always contains two empty objects (properties are null or 0), i.e. the default value which I set for this property. If I set no default value, then I won't have any fields to edit for this property in the popup editor. All the other properties are updated as expected.

What bugs me is that if I use server binding instead of AJAX, then all the data is correctly received. So I decided to check out the data in the request headers being sent in both cases:

// Using server binding
ReleaseID:300
NoteID:886
ItemType:1
ReleaseNoteTranslations[0].ItemID:886
ReleaseNoteTranslations[0].LanguageID:1
ReleaseNoteTranslations[0].TranslationID:869
ReleaseNoteTranslations[0].Translation:The module is now released!
ReleaseNoteTranslations[1].ItemID:886
ReleaseNoteTranslations[1].LanguageID:2
ReleaseNoteTranslations[1].TranslationID:870
ReleaseNoteTranslations[1].Translation:Le module est maintenant disponible!
NoteID:886

// Using AJAX binding
sort:
group:
filter:
NoteID:886
ReleaseID:300
ReleaseNoteTranslations[0][TranslationID]:869
ReleaseNoteTranslations[0][Translation]:The module is now released!
ReleaseNoteTranslations[0][LanguageID]:1
ReleaseNoteTranslations[0][ItemID]:886
ReleaseNoteTranslations[1][TranslationID]:870
ReleaseNoteTranslations[1][Translation]:Le module est maintenant disponible!
ReleaseNoteTranslations[1][LanguageID]:2
ReleaseNoteTranslations[1][ItemID]:886
ItemType:1

Now what I notice first here is the syntax of objectName[index].PropertyName vs objectName[index][PropertyName]

I wonder if this could be the cause of my problem, and if so, is there a way for me to go and directly manipulate the data being sent to fix it? Could this be a bug in the way Kendo Grid sends data through Ajax binding?

Either way, any help would be much appreciated!

Solution

So In case anyone stumbles on this in the future, I contacted Telerik support, who explained to me that:

The dataSource supports only value types and will not serialize the arrays in the format that is expected by the model binder.

They also provided me with a workaround using the request Data function to call a JavaScript function which converts the data into the correct format.

In the view, modify the request functions by specifying the name of the JavaScript function to call:

.Create(create => create.Action("AddNote", "ReleaseNotes").Data("serialize"))

And then add in the functions which will do the conversion:

function serialize(data) {
    for (var property in data) {
        if ($.isArray(data[property])) {
            serializeArray(property, data[property], data);
        }
    }
}
function serializeArray(prefix, array, result) {
    for (var i = 0; i < array.length; i++) {
        for (var property in array[i]) {
            result[prefix + "[" + i + "]." + property] = array[i][property];
        }
    }
}