Cascading ComboBoxes with BatchEditing and Master/Detail Hierarchy

Description

Implement Cascading ComboBoxes with BatchEditing (EditMode="Batch") and Master/Detail Hierarchy using the Grid and BatchEditing Client-Side APIs.

Scenarios

• Change the ComboBox selection in the Parent Item to cascade the changes down to the Child Items
• Change the ComboBox selection in the Child Item to cascade the changes up to the Parent Item as well as to the sibling Child Items

DEMO

Solution

To implement the cascading functionalities, write a JavaScript logic using the combination of RadGrid and BatchEditing client-side APIs within the OnBatchEditCellValueChanged client-side event.

JavaScript code for the Cascading functionality

JavaScript

<script type="text/javascript">
    function OnBatchEditCellValueChanged(sender, args) {
        // Use timeout only to execute logic in an order
        // Note: it is required to ensure the cascading changes do not happen before the BatchEditing finishes the action selected by user
        setTimeout(function () {
            var grid = sender;
            // Get reference to BatchEditing Manager
            var batchManager = grid.get_batchEditingManager();
            // Get the new value from the Editor Control (in this case, the ComboBox)
            var newValue = args.get_editorValue();
            // Get reference to the TableView of the row that is being Changed
            var currentTableView = args.get_tableView();
            // Get the TableView's name
            var tableViewName = currentTableView.get_name();
            // Get reference to the row element (TR)
            var currentRowElement = args.get_row();

            // Call the TableView's get_dataItem() function to instantiate its Telerik.Web.UI.GridDataItems.
            // Note: this is required to be able to cast a row element (<tr>) to Telerik.Web.UI.GridDataItem Object.
            currentTableView.get_dataItems();

            // Check if the row element exists and it has a property called "control"
            if (currentRowElement && currentRowElement.control) {
                // Cast the row element (TR) to Telerik.Web.UI.GridDataItem Object
                var dataItem = currentRowElement.control;

                // Condition to check which TableView's row is being changed
                if (tableViewName == "Orders") { // if changes are made to the MasterTable (Orders)

                    // Get the DetailTables collection
                    var detailTables = dataItem.get_nestedViews();

                    // Iterate through the DetailTables
                    for (var detailTableIndex = 0; detailTableIndex < detailTables.length; detailTableIndex++) {
                        // Reference the Current DetailTable by index
                        var detailTable = detailTables[detailTableIndex];
                        // Get reference to the DetailTable's items
                        var childItems = detailTable.get_dataItems();
                        // Iterate through the DetailTable's Items
                        for (var childItemIndex = 0; childItemIndex < childItems.length; childItemIndex++) {
                            var childItem = childItems[childItemIndex];
                            // Get reference to the Child Item's Country Cell
                            var childItemCountryCell = childItem.get_cell("ShipCountry");
                            // Change the Cell's Value to the value coming from the Paren item's ComboBox
                            batchManager.changeCellValue(childItemCountryCell, newValue)
                        }
                    }
                } else if (tableViewName == "OrderDetails") { // if changes are made to the DetailTable (OrderDetailss)
                    var masterTableView = currentTableView.get_parent();
                    // Call the Master TableView's get_dataItem() function to instantiate its Telerik.Web.UI.GridDataItems.
                    // Note: this is required to be able to cast a row element (<tr>) to Telerik.Web.UI.GridDataItem Object.
                    masterTableView.get_dataItems();

                    // Access the Parent row element (TR)
                    var parentRowElement = currentTableView.get_parentRow();

                    // Check if the row element exists and it has a property called "control"
                    if (parentRowElement && parentRowElement.control) {
                        // Cast the row element (TR) to Telerik.Web.UI.GridDataItem Object
                        var parentDataItem = parentRowElement.control;
                        // Get reference to the Parent Item's Country Cell
                        var parentCountryCell = parentDataItem.get_cell("ShipCountry");
                        // Change the Cell's Value to the value coming from the Child item's ComboBox
                        batchManager.changeCellValue(parentCountryCell, newValue)
                    }
                }
            }
        }, 15)
    }
</script>

The JavaScript code from above was designed for the following Grid structure. You may need to adjust the code according to the structure in your app.

RadGrid structure

ASP.NET

<telerik:RadGrid ID="RadGrid1" runat="server" AllowPaging="True" Width="800px"
    OnNeedDataSource="RadGrid1_NeedDataSource"
    OnDetailTableDataBind="RadGrid1_DetailTableDataBind" OnPreRender="RadGrid1_PreRender">
    <MasterTableView Name="Orders" AutoGenerateColumns="False" DataKeyNames="OrderID" EditMode="Batch" HierarchyDefaultExpanded="true" Caption="Orders Table">
        <BatchEditingSettings EditType="Cell" />
        <Columns>
            <telerik:GridNumericColumn DataField="OrderID" DataType="System.Int32"
                FilterControlAltText="Filter OrderID column" HeaderText="OrderID"
                ReadOnly="True" SortExpression="OrderID" UniqueName="OrderID">
            </telerik:GridNumericColumn>
            <telerik:GridDateTimeColumn DataField="OrderDate" DataType="System.DateTime"
                FilterControlAltText="Filter OrderDate column" HeaderText="OrderDate"
                SortExpression="OrderDate" UniqueName="OrderDate">
            </telerik:GridDateTimeColumn>
            <telerik:GridNumericColumn DataField="Freight" DataType="System.Decimal"
                FilterControlAltText="Filter Freight column" HeaderText="Freight"
                SortExpression="Freight" UniqueName="Freight">
            </telerik:GridNumericColumn>
            <telerik:GridBoundColumn DataField="ShipName"
                FilterControlAltText="Filter ShipName column" HeaderText="ShipName"
                SortExpression="ShipName" UniqueName="ShipName">
            </telerik:GridBoundColumn>
            <telerik:GridTemplateColumn DataField="ShipCountry"
                FilterControlAltText="Filter ShipCountry column" HeaderText="ShipCountry"
                SortExpression="ShipCountry" UniqueName="ShipCountry">
                <ItemTemplate>
                    <%# Eval("ShipCountry") %>
                </ItemTemplate>
                <EditItemTemplate>
                    <telerik:RadComboBox ID="MasterComboBox" runat="server" RenderMode="Lightweight" DataTextField="ShipCountry" DataValueField="ShipCountry">
                    </telerik:RadComboBox>
                </EditItemTemplate>
            </telerik:GridTemplateColumn>
        </Columns>
        <DetailTables>
            <telerik:GridTableView Name="OrderDetails" AutoGenerateColumns="false" EditMode="Batch" Caption="OrderDetails Table">
                <BatchEditingSettings EditType="Cell" />
                <Columns>
                    <telerik:GridNumericColumn DataField="OrderID" DataType="System.Int32"
                        FilterControlAltText="Filter OrderID column" HeaderText="OrderID"
                        ReadOnly="True" SortExpression="OrderID" UniqueName="OrderID">
                    </telerik:GridNumericColumn>
                    <telerik:GridNumericColumn DataField="UnitPrice" DataType="System.Decimal"
                        FilterControlAltText="Filter UnitPrice column" HeaderText="UnitPrice"
                        SortExpression="UnitPrice" UniqueName="UnitPrice">
                    </telerik:GridNumericColumn>
                    <telerik:GridNumericColumn DataField="Quantity" DataType="System.Int32"
                        FilterControlAltText="Filter Quantity column" HeaderText="Quantity"
                        SortExpression="Quantity" UniqueName="Quantity">
                    </telerik:GridNumericColumn>
                    <telerik:GridNumericColumn DataField="Discount" DataType="System.Decimal"
                        FilterControlAltText="Filter Discount column" HeaderText="Discount"
                        SortExpression="Discount" UniqueName="Discount">
                    </telerik:GridNumericColumn>
                    <telerik:GridTemplateColumn DataField="ShipCountry"
                        FilterControlAltText="Filter ShipCountry column" HeaderText="ShipCountry"
                        SortExpression="ShipCountry" UniqueName="ShipCountry">
                        <ItemTemplate>
                            <%# Eval("ShipCountry") %>
                        </ItemTemplate>
                        <EditItemTemplate>
                            <telerik:RadComboBox ID="ChildComboBox" runat="server" RenderMode="Lightweight" DataTextField="ShipCountry" DataValueField="ShipCountry">
                            </telerik:RadComboBox>
                        </EditItemTemplate>
                    </telerik:GridTemplateColumn>
                </Columns>
            </telerik:GridTableView>
        </DetailTables>
    </MasterTableView>
    <ClientSettings>
        <ClientEvents OnBatchEditCellValueChanged="OnBatchEditCellValueChanged" />
    </ClientSettings>
</telerik:RadGrid>

CodeBehind (backend) code for data binding.

C#

protected void RadGrid1_NeedDataSource(object sender, GridNeedDataSourceEventArgs e)
{
    (sender as RadGrid).DataSource = OrdersTable();
}

protected void RadGrid1_DetailTableDataBind(object sender, GridDetailTableDataBindEventArgs e)
{
    if (e.DetailTableView.Name == "OrderDetails")
    {
        GridDataItem parentItem = e.DetailTableView.ParentItem;

        int orderId = (int)parentItem.GetDataKeyValue("OrderID");

        e.DetailTableView.DataSource = OrderDetailsTable().Select(string.Format("OrderID = '{0}'", orderId));
    }
}

private DataTable OrdersTable()
{
    DataTable dt = new DataTable();

    dt.Columns.Add(new DataColumn("OrderID", typeof(int)));
    dt.Columns.Add(new DataColumn("OrderDate", typeof(DateTime)));
    dt.Columns.Add(new DataColumn("Freight", typeof(double)));
    dt.Columns.Add(new DataColumn("ShipName", typeof(string)));
    dt.Columns.Add(new DataColumn("ShipCountry", typeof(string)));

    dt.PrimaryKey = new DataColumn[] { dt.Columns["OrderID"] };

    for (int i = 0; i < 3; i++)
    {
        int index = i + 1;

        DataRow row = dt.NewRow();

        row["OrderID"] = index;
        row["OrderDate"] = DateTime.Now.Date.AddDays(index);
        row["Freight"] = index * 0.01;
        row["ShipName"] = "Name " + index;
        row["ShipCountry"] = "Country " + index;

        dt.Rows.Add(row);
    }

    return dt;
}
private DataTable OrderDetailsTable()
{
    DataTable dt = new DataTable();

    dt.Columns.Add(new DataColumn("OrderID", typeof(int)));
    dt.Columns.Add(new DataColumn("UnitPrice", typeof(decimal)));
    dt.Columns.Add(new DataColumn("Quantity", typeof(int)));
    dt.Columns.Add(new DataColumn("Discount", typeof(decimal)));
    dt.Columns.Add(new DataColumn("ShipCountry", typeof(string)));

    var orders = OrdersTable();

    int itemsPerOrder = 3;

    for (int rowIndex = 0; rowIndex < orders.Rows.Count; rowIndex++)
    {
        DataRow currentOrder = orders.Rows[rowIndex];

        for (int j = 0; j < itemsPerOrder; j++)
        {
            int index = j + 1;

            DataRow row = dt.NewRow();

            row["OrderID"] = currentOrder["OrderID"];

            row["UnitPrice"] = index;
            row["Quantity"] = index;
            row["Discount"] = index * 0.01;
            row["ShipCountry"] = "Country " + index;

            dt.Rows.Add(row);
        }
    }
    return dt;
}


protected void RadGrid1_PreRender(object sender, EventArgs e)
{
    RadGrid grid = (RadGrid)sender;
    GridTableView masterTable = grid.MasterTableView;

    RadComboBox combo = masterTable.GetBatchEditorContainer("ShipCountry").FindControl("MasterComboBox") as RadComboBox;
    combo.DataSource = OrdersTable();
    combo.DataBind();

    foreach (GridDataItem masterItem in masterTable.Items)
    {
        if (masterItem.HasChildItems)
        {
            GridNestedViewItem nestedItem = masterItem.ChildItem;

            foreach (GridTableView childTableView in nestedItem.NestedTableViews)
            {
                Panel batchEditorContainer = childTableView.GetBatchEditorContainer("ShipCountry");

                if(batchEditorContainer != null)
                {
                    RadComboBox childCombo = batchEditorContainer.FindControl("ChildComboBox") as RadComboBox;
                    childCombo.DataSource = OrdersTable();
                    childCombo.DataBind();
                }
            }
        }
    }
}

VB

Protected Sub RadGrid1_NeedDataSource(ByVal sender As Object, ByVal e As GridNeedDataSourceEventArgs)
    CType(sender, RadGrid).DataSource = OrdersTable()
End Sub

Protected Sub RadGrid1_DetailTableDataBind(ByVal sender As Object, ByVal e As GridDetailTableDataBindEventArgs)
    If e.DetailTableView.Name = "OrderDetails" Then
        Dim parentItem As GridDataItem = e.DetailTableView.ParentItem
        Dim orderId As Integer = CInt(parentItem.GetDataKeyValue("OrderID"))
        e.DetailTableView.DataSource = OrderDetailsTable().[Select](String.Format("OrderID = '{0}'", orderId))
    End If
End Sub

Private Function OrdersTable() As DataTable
    Dim dt As DataTable = New DataTable()
    dt.Columns.Add(New DataColumn("OrderID", GetType(Integer)))
    dt.Columns.Add(New DataColumn("OrderDate", GetType(DateTime)))
    dt.Columns.Add(New DataColumn("Freight", GetType(Double)))
    dt.Columns.Add(New DataColumn("ShipName", GetType(String)))
    dt.Columns.Add(New DataColumn("ShipCountry", GetType(String)))
    dt.PrimaryKey = New DataColumn() {dt.Columns("OrderID")}

    For i As Integer = 0 To 3 - 1
        Dim index As Integer = i + 1
        Dim row As DataRow = dt.NewRow()
        row("OrderID") = index
        row("OrderDate") = DateTime.Now.Date.AddDays(index)
        row("Freight") = index * 0.01
        row("ShipName") = "Name " & index
        row("ShipCountry") = "Country " & index
        dt.Rows.Add(row)
    Next

    Return dt
End Function

Private Function OrderDetailsTable() As DataTable
    Dim dt As DataTable = New DataTable()
    dt.Columns.Add(New DataColumn("OrderID", GetType(Integer)))
    dt.Columns.Add(New DataColumn("UnitPrice", GetType(Decimal)))
    dt.Columns.Add(New DataColumn("Quantity", GetType(Integer)))
    dt.Columns.Add(New DataColumn("Discount", GetType(Decimal)))
    dt.Columns.Add(New DataColumn("ShipCountry", GetType(String)))
    Dim orders = OrdersTable()
    Dim itemsPerOrder As Integer = 3

    For rowIndex As Integer = 0 To orders.Rows.Count - 1
        Dim currentOrder As DataRow = orders.Rows(rowIndex)

        For j As Integer = 0 To itemsPerOrder - 1
            Dim index As Integer = j + 1
            Dim row As DataRow = dt.NewRow()
            row("OrderID") = currentOrder("OrderID")
            row("UnitPrice") = index
            row("Quantity") = index
            row("Discount") = index * 0.01
            row("ShipCountry") = "Country " & index
            dt.Rows.Add(row)
        Next
    Next

    Return dt
End Function

Protected Sub RadGrid1_PreRender(ByVal sender As Object, ByVal e As EventArgs)
    Dim grid As RadGrid = CType(sender, RadGrid)
    Dim masterTable As GridTableView = grid.MasterTableView
    Dim combo As RadComboBox = TryCast(masterTable.GetBatchEditorContainer("ShipCountry").FindControl("MasterComboBox"), RadComboBox)
    combo.DataSource = OrdersTable()
    combo.DataBind()

    For Each masterItem As GridDataItem In masterTable.Items

        If masterItem.HasChildItems Then
            Dim nestedItem As GridNestedViewItem = masterItem.ChildItem

            For Each childTableView As GridTableView In nestedItem.NestedTableViews
                Dim batchEditorContainer As Panel = childTableView.GetBatchEditorContainer("ShipCountry")

                If batchEditorContainer IsNot Nothing Then
                    Dim childCombo As RadComboBox = TryCast(batchEditorContainer.FindControl("ChildComboBox"), RadComboBox)
                    childCombo.DataSource = OrdersTable()
                    childCombo.DataBind()
                End If
            Next
        End If
    Next
End Sub

This CodeBehind code is only for demonstration purposes. You may use this to test the current example.