Raising client event for rows once in hierarchical grid

By default the client event bubbling mechanism of Telerik RadGrid will raise all row events once for the respective row in the grid hierarchy and once for each NestedView which wraps the inner grid row. To prevent that from happening (if necessary), you can perform the following conditional check in the corresponding client event handler:

if (eventArgs.get_tableView().get_name() == "DetailTable") {
  alert("Event executed only once for each double-clicked row in the hierarchy");
  //execute some custom logic here
}

In the next section you can find the code of a simple example which propagates the logic mentioned above hooking the OnRowDblClick event of Telerik RadGrid (keep in mind that for performance reasons, the RadGridTable.Rows collection is available only when you enable specific client features/events for the rows in the grid (such AllowRowResize, AllowRowSelect, OnRowClick, etc.)):

<script type="text/javascript">    
function RowDblClick(sender, eventArgs) {
    if (eventArgs.get_tableView().get_name() == "DetailTable") {
      alert("Event executed only once for each double-clicked row in the hierarchy");
      //execute some custom logic here     
    }
  }
</script>
<telerik:RadGrid RenderMode="Lightweight" ID="RadGrid1" runat="server" AutoGenerateColumns="False" PageSize="3"
  AllowSorting="True" AllowPaging="True">
  <PagerStyle Mode="NumericPages"></PagerStyle>
  <MasterTableView DataKeyNames="CustomerID" AllowMultiColumnSorting="True" Width="100%">
    <DetailTables>
      <telerik:GridTableView DataKeyNames="OrderID" DataMember="Orders" Width="100%" GridLines="Horizontal">
        <ParentTableRelation>
          <telerik:GridRelationFields DetailKeyField="CustomerID" MasterKeyField="CustomerID" />
        </ParentTableRelation>
        <DetailTables>
          <telerik:GridTableView DataKeyNames="OrderID" DataMember="OrderDetails" Width="100%"
            GridLines="Horizontal">
            <ParentTableRelation>
              <telerik:GridRelationFields DetailKeyField="OrderID" MasterKeyField="OrderID" />
            </ParentTableRelation>
            <Columns>
              <telerik:GridBoundColumn SortExpression="UnitPrice" HeaderText="Unit Price" HeaderButtonType="TextButton"
                DataField="UnitPrice">
              </telerik:GridBoundColumn>
              <telerik:GridBoundColumn SortExpression="Quantity" HeaderText="Quantity" HeaderButtonType="TextButton"
                DataField="Quantity">
              </telerik:GridBoundColumn>
              <telerik:GridBoundColumn SortExpression="Discount" HeaderText="Discount" HeaderButtonType="TextButton"
                DataField="Discount">
              </telerik:GridBoundColumn>
            </Columns>
          </telerik:GridTableView>
        </DetailTables>
        <Columns>
          <telerik:GridBoundColumn SortExpression="OrderID" HeaderText="OrderID" HeaderButtonType="TextButton"
            DataField="OrderID">
          </telerik:GridBoundColumn>
          <telerik:GridBoundColumn SortExpression="OrderDate" HeaderText="Date Ordered" HeaderButtonType="TextButton"
            DataField="OrderDate">
          </telerik:GridBoundColumn>
          <telerik:GridBoundColumn SortExpression="EmployeeID" HeaderText="EmployeeID" HeaderButtonType="TextButton"
            DataField="EmployeeID">
          </telerik:GridBoundColumn>
        </Columns>
      </telerik:GridTableView>
    </DetailTables>
    <Columns>
      <telerik:GridBoundColumn SortExpression="CustomerID" HeaderText="CustomerID" HeaderButtonType="TextButton"
        DataField="CustomerID">
      </telerik:GridBoundColumn>
      <telerik:GridBoundColumn SortExpression="ContactName" HeaderText="Contact Name" HeaderButtonType="TextButton"
        DataField="ContactName">
      </telerik:GridBoundColumn>
      <telerik:GridBoundColumn SortExpression="CompanyName" HeaderText="Company" HeaderButtonType="TextButton"
        DataField="CompanyName">
      </telerik:GridBoundColumn>
    </Columns>
  </MasterTableView>
  <ClientSettings>
    <Selecting AllowRowSelect="true" />
    <ClientEvents OnRowDblClick="RowDblClick" />
  </ClientSettings>
</telerik:RadGrid>