Grid DetailTemplate exception when Data is null?

[Rob]

I'm getting this error when bound data list for a detail template is null

I don't have a Parameter 'source' in any model so don't understand what this is in reference to?

 

<DetailTemplate>
    <div class="form-group form-inline right">
        @{
            var bookingEquip = context as BookingEquipmentModel;
            <TelerikGrid @ref="@bookingEquipmentCommodityGridRef" 
                         Data="bookingEquip.Commodities"
                         Pageable="true"
                         PageSize="4"
                         Resizable="true"
                         Size="@ThemeConstants.Grid.Size.Small"
                         Width="90rem"
                         EditMode="@GridEditMode.Incell"
                         OnDelete="@((GridCommandEventArgs args) => OnCommodityDelete(args, bookingEquip))"
                         OnCreate="@((GridCommandEventArgs args) => OnCommodityCreate(args, bookingEquip))"
                         OnUpdate="@((GridCommandEventArgs args) => OnCommodityUpdate(bookingEquip, args))">
                <GridToolBarTemplate>
                    <!-- can only add a single commodity if there are none associated with this equipment) -->
                    <GridCommandButton Command="Add" Class="btn-green" Icon="@FontIcon.Plus" Enabled="@(!bookingEquip.Commodities.Any())">Add Commodity</GridCommandButton>
                </GridToolBarTemplate>
                <GridColumns>
                    <!-- Commodity Types -->
                    <GridColumn Field=@nameof(BookingEquipmentCommodityModel.CommodityType) Editable="true" Title="Description" Width="6rem">
                        <EditorTemplate Context="cbecContext">
                            @{
                                _currentBookingEquipmentCommodityModel = cbecContext as BookingEquipmentCommodityModel;
                                if (_currentBookingEquipmentCommodityModel != null)
                                {
                                    <TelerikDropDownList Data="@_CommodityList"
                                                         Value="@_currentBookingEquipmentCommodityModel.CommodityTypeId"

for the Data reference, bookingEquip is NOT null but it's property bookingEquip.Commodities is indeed null (expected).

The grid displays correctly, but as soon as I click on the "+" expand it will crash with exception in the control.

I'm puzzled as to why this is happening?  When I populate other grids (not using a DetailTemplate) in my Blazor app, and the Data reference is a null, nothing is displayed/render in the grid and I just get a "No records available." ... which is good.  But the same behavior doesn't seem to happen when using DetailTemplate?

Any suggestions?

Rob.

 

 

 

[Rob]

SOLVED ... I needed to instantiate the commodities list even if no items in the list.