Changing table layout in a self referencing Hierarchy

[Jonathan]

Hi

I have an expanding grid with a self referencing hierarchy that can go to a variable depth so I can't use nested detail tables, so after some experimenting I started using the self referencing hierarchy and came up with the following code.

<telerik:RadGrid ID="RadGrid1" runat="server" AutoGenerateColumns="False"
    OnDetailTableDataBind="RadGrid1_DetailTableDataBind" GridLines="None"
    onitemdatabound="RadGrid1_ItemDataBound" >
    <MasterTableView DataKeyNames="ParentID, LearningObjectID, IsCriteria, ShowOverview, ShowNotes, ShowSchematic, LearningObject_Overview, LearningObject_Notes, SchematicFilename, OriginalSchematicFilename" AllowSorting="true" Width="100%" HierarchyLoadMode="ServerOnDemand" CommandItemDisplay="Top">
        <CommandItemTemplate>
            <asp:Table ID="tblInfo" runat="server">
                <asp:TableRow ID="rowOverview">
                    <asp:TableCell>
                        <asp:Label ID="ttlOverview" Font-Bold="true" Font-Size="Small" ForeColor="Black" runat="server" Text="Overview:"></asp:Label>
                    </asp:TableCell>
                    <asp:TableCell>
                        <asp:Label ID="txtOverview" Font-Size="Small" ForeColor="Black" runat="server"></asp:Label>
                    </asp:TableCell>
                </asp:TableRow>
                <asp:TableRow ID="rowNotes">
                    <asp:TableCell>
                        <asp:Label ID="ttlNotes" Font-Bold="true" Font-Size="Small" ForeColor="Black" runat="server" Text="Notes:"></asp:Label>
                    </asp:TableCell>
                    <asp:TableCell>
                        <asp:Label ID="txtNotes" Font-Size="Small" ForeColor="Black" runat="server"></asp:Label>
                    </asp:TableCell>
                </asp:TableRow>
                <asp:TableRow ID="rowSchematic">
                    <asp:TableCell>
                        <asp:Label ID="ttlSchematic" Font-Bold="true" Font-Size="Small" ForeColor="Black" runat="server" Text="Schematic:"></asp:Label>
                    </asp:TableCell>
                    <asp:TableCell>
                        <asp:HyperLink ID="lnkSchematic" Font-Size="Small" ForeColor="Black" runat="server" Text="Click Here To View" Target="_blank" />
                        <asp:Label ID="txtSchematic" Font-Size="Small" ForeColor="Black" runat="server" Text="There is no schematic for this entry"></asp:Label>
                    </asp:TableCell></asp:TableRow></asp:Table></CommandItemTemplate><CommandItemSettings ExportToPdfText="Export to Pdf">
        </CommandItemSettings>
        <SelfHierarchySettings ParentKeyName="ParentID" KeyName="LearningObjectID" />
        <RowIndicatorColumn>
            <HeaderStyle Width="20px"></HeaderStyle>
        </RowIndicatorColumn>
        <ExpandCollapseColumn>
            <HeaderStyle Width="20px"></HeaderStyle>
        </ExpandCollapseColumn>

        <Columns>
            <telerik:GridImageColumn HeaderStyle-Width="20px" DataImageUrlFields="IconURL"></telerik:GridImageColumn>
            <telerik:GridBoundColumn DataField="Code" HeaderText="<%$ Resources:Code %>"
                SortExpression="Code" UniqueName="Code" HeaderStyle-Width="100px" ItemStyle-Width="100px">
            </telerik:GridBoundColumn>
            <telerik:GridBoundColumn DataField="LearningObjective"
                HeaderText="<%$ Resources:LearningObjective %>" SortExpression="LearningObjective"
                UniqueName="LearningObjective">
            </telerik:GridBoundColumn>
            <telerik:GridBoundColumn DataField="CriticalPercentage"
                DataType="System.Double" HeaderStyle-Width="75px" ItemStyle-Width="75px" HeaderText="<%$ Resources:CriticalPercentage %>" ReadOnly="True"
                SortExpression="CriticalPercentage" UniqueName="CriticalPercentage" DataFormatString="{0}%">
            </telerik:GridBoundColumn>
            <telerik:GridBoundColumn DataField="NonCriticalPercentage"
                DataType="System.Double" HeaderStyle-Width="75px" ItemStyle-Width="75px" HeaderText="<%$ Resources:NonCriticalPercentage %>" ReadOnly="True"
                SortExpression="NonCriticalPercentage" UniqueName="NonCriticalPercentage" DataFormatString="{0}%">
            </telerik:GridBoundColumn>
        </Columns>
    </MasterTableView>

</telerik:RadGrid>

and the codebehind is

protected void RadGrid1_DetailTableDataBind(object source, GridDetailTableDataBindEventArgs e)
{
    //Get the info on the parent item
    GridDataItem parentItem = e.DetailTableView.ParentItem as GridDataItem;
    int LearningObjectID = (int)parentItem.GetDataKeyValue("LearningObjectID");

    //Get the info on the table that is to be opened.
    CMASDALTableAdapters.AssessUsersPositionSuitabilityTableAdapter assessment = new CMASDALTableAdapters.AssessUsersPositionSuitabilityTableAdapter();
    CMASDAL.AssessUsersPositionSuitabilityDataTable dt = assessment.GetAssessUsersPositionSuitability(int.Parse(Session["ClientID"].ToString()), EmployeeSelector1.SelectedPositionID, LearningObjectID, EmployeeSelector1.SelectedEmployeeID);

    //Check it has children
    if (dt.Count > 0)
    {
        //Find out if the children are criteria and therefore the bottom level and need the alternate table layout.
        if (dt[0].IsCriteria)
        {
            //Get the data for the new table layout
            CMASDALTableAdapters.AssessUsersPositionSuitabilityCriteriaTableAdapter assessment2 = new CMASDALTableAdapters.AssessUsersPositionSuitabilityCriteriaTableAdapter();
            e.DetailTableView.DataSource = assessment2.GetAssessUsersPositionSuitabilityCriteria(int.Parse(Session["ClientID"].ToString()), EmployeeSelector1.SelectedPositionID, LearningObjectID, EmployeeSelector1.SelectedEmployeeID);
            //Add the additional columns that I need to my collection.
            //Important: first Add column to the collection
            GridBoundColumn nameColumn = new GridBoundColumn();
            e.DetailTableView.Columns.Add(nameColumn);
            //Then set properties
            nameColumn.DataField = "AssessorName";
            nameColumn.HeaderText = "Assessor";
            nameColumn.HeaderStyle.Width = 150;

            //Important: first Add column to the collection
            GridBoundColumn dateColumn = new GridBoundColumn();
            e.DetailTableView.Columns.Add(dateColumn);
            //Then set properties
            dateColumn.DataField = "AssessmentDate";
            dateColumn.HeaderText = "Assessment Date";
            dateColumn.HeaderStyle.Width = 75;
            dateColumn.DataFormatString = "{0:d}";

            //Important: first Add column to the collection
            GridBoundColumn statusColumn = new GridBoundColumn();
            e.DetailTableView.Columns.Add(statusColumn);
            //Then set properties
            statusColumn.DataField = "AssessmentStatus";
            statusColumn.HeaderText = "Assessment Status";
            statusColumn.HeaderStyle.Width = 75;
            //Important: first Add column to the collection
            GridBoundColumn method1Column = new GridBoundColumn();
            e.DetailTableView.Columns.Add(method1Column);
            //Then set properties
            method1Column.DataField = "AssessmentMethod1";
            method1Column.HeaderText = "Assessment Method 1";
            method1Column.HeaderStyle.Width = 75;
            //Important: first Add column to the collection
            GridBoundColumn method2Column = new GridBoundColumn();
            e.DetailTableView.Columns.Add(method2Column);
            //Then set properties
            method2Column.DataField = "AssessmentMethod2";
            method2Column.HeaderText = "Assessment Method 2";
            method2Column.HeaderStyle.Width = 75;
            //Get rid of the columns I don't need.
            GridColumn critPercentageCol = e.DetailTableView.Columns[3];
            GridColumn nonCritPercentageCol = e.DetailTableView.Columns[4];
            e.DetailTableView.Columns.Remove(critPercentageCol);
            e.DetailTableView.Columns.Remove(nonCritPercentageCol);
            //GridColumn newCol = new GridColumn();

            //e.DetailTableView.Columns.Add();
        }
        else
            e.DetailTableView.DataSource = dt;
    }
    else
        e.DetailTableView.DataSource = dt;
}
protected void RadGrid1_ItemDataBound(object sender, GridItemEventArgs e)
{
    //If its the command area prepare to show overview/notes etc.
    if (e.Item is GridCommandItem)
    {
        GridDataItem parentItem = e.Item.OwnerTableView.ParentItem as GridDataItem;
        if (parentItem != null)
        {
            //Get the information about the parent item
            bool showOverview = (bool)parentItem.GetDataKeyValue("ShowOverview");
            bool showNotes = (bool)parentItem.GetDataKeyValue("ShowNotes");
            bool showSchematic = (bool)parentItem.GetDataKeyValue("ShowSchematic");
            string strOverview = (string)parentItem.GetDataKeyValue("LearningObject_Overview");
            string strNotes = (string)parentItem.GetDataKeyValue("LearningObject_Notes");
            string lnkSchematicFilename = (string)parentItem.GetDataKeyValue("SchematicFilename");
            GridCommandItem commandItem = (GridCommandItem)e.Item;
            //Show and hide appropriate fields.
            if (showOverview)
            {
                Label txtOverview = (Label)commandItem.FindControl("txtOverview");
                txtOverview.Text = strOverview;
            }
            else
            {
                TableRow rowOverview = (TableRow)commandItem.FindControl("rowOverview");
                rowOverview.Visible = false;
            }
            if (showNotes)
            {
                Label txtNotes = (Label)commandItem.FindControl("txtNotes");
                txtNotes.Text = strNotes;
            }
            else
            {
                TableRow rowNotes = (TableRow)commandItem.FindControl("rowNotes");
                rowNotes.Visible = false;
            }
            if (showSchematic)
            {
                Label txtSchematic = (Label)commandItem.FindControl("txtSchematic");
                HyperLink lnkSchematic = (HyperLink)commandItem.FindControl("lnkSchematic");
                if (lnkSchematicFilename.Length == 0)
                    lnkSchematic.Visible = false;
                else
                {
                    lnkSchematic.NavigateUrl = lnkSchematicFilename;
                    txtSchematic.Visible = false;
                }
            }
            else
            {
                TableRow rowSchematic = (TableRow)commandItem.FindControl("rowSchematic");
                rowSchematic.Visible = false;
            }
        }
        else
            e.Item.Visible = false;
    }
    //if it's a criteria then hide the expand control
    if (e.Item is GridDataItem)// to access a row
    {
        GridDataItem item = (GridDataItem)e.Item;
        RadGrid parentGrid = (RadGrid)sender;
        if ((bool)item.GetDataKeyValue("IsCriteria") == true)
        {
            item.Cells[0].Controls[0].Visible = false;
        }
    }
}

At first this approach seemed to work
Screenshot
but if I then expanded another row it would cut out my addidtional columns in my modified detail table.
Screenshot 2

Is it possible to modify a detail table view so that the changes persist on another row expanding?
Is there an easier/better way to do what I am attempting to do i.e. a self referencing grid with a different detail view at the lowest level?

Any help/advice will be gratefully received.

Jon

[Iana Tsolova]

Hello Jonathan,

I reviewed your code and here are my finding:

    - In order to bind the self-referencing grid, you need to handle the NeedDataSource and there assign DataSource for the grid. 
    - Adding columns after Page_Init, Page_Load is not suggested. Furthermore mixing declarative and dynamic columns is not supported for the grid. I suggest that you add the problematic columns in the grid declaration along with the other columns. Then on grid PreRender, you can set their Visible property to false for the particular table view.

Check it out and let me know if this works for you.

Sincerely yours,
Iana
the Telerik team