How do you dynamically add the DataFieldY value for a RadHtmlChart?

Question

When makeing a PieSeries chart with telerik:RadHtmlChart

Would it be possible and if so how would you set the DataFieldY attribute to the name of the fist column in an Excel upload?

<telerik:RadHtmlChart runat="server" ID="RadHtmlChart1" Transitions="false" Width="450"
    Height="450" Skin="Silk">
    <Legend>
        <Appearance Visible="false"></Appearance>
    </Legend>
    <PlotArea>
        <Series>
            <telerik:PieSeries DataFieldY="Number" NameField="Fruit" ExplodeField="IsExploded">
            </telerik:PieSeries>
        </Series>
    </PlotArea>
</telerik:RadHtmlChart>

This would need to be done by client-side binding.

public string chartData = "[{'Fruit': 'Apple','Number': 8, 'Color': 'Blue'},{'Fruit': 'Orange','Number': 4, 'Color': 'Purple'},{'Fruit': 'Banana','Number': 3, 'Color': 'Red'},{'Fruit': 'Grapes','Number': 12, 'Color': 'Pink'},{'Fruit': 'Peace','Number': 2, 'Color': 'Orange'}]";

var jsonChartData = "<%=chartData%>";

                    var RadHtmlChart1 = $find('<%=RadHtmlChart1.ClientID %>');
                    RadHtmlChart1.set_dataSource(jsonChartData);
                    RadHtmlChart1.set_transitions(true);
                    RadHtmlChart1.repaint();

Answer 1

You can't do that directly. The control can work with several data sources:

• JavaScript arrays of JSON literals (as you have pasted)

• an IEnumerable collection (provided by a declarative data source control like SqlDataSource; or a List; or a DataTable, you get the idea)

Excel files are neither.

You would need to parse the excel file somehow to get the needed collection:

• perhaps the Microsoft Interop assemblies can help

• or the Telerik SpreadProcessing (e.g., ICellValue value = this.radSpreadsheet.ActiveWorksheet.Cells[0, 1].GetValue().Value;, taken from http://www.telerik.com/forums/basic-xslx-import-export-functionality-through-a-dataset)

• some other solution is certainly available