Custom Provider

The following article demonstrates how to implement a custom provider for the RadSpreadsheet.

Implementing the Provider

In order to implement a custom provider for the RadSpreadsheet you would need to create a class that inherits the SpreadsheetProviderBase class. The custom class should implement the SaveWorkbook and GetSheets methods, which provide the end points for reading and writing data to the Spreadsheet. The following steps will help you to easily create and implement a custom provider for the RadSpreadsheet.

1. Create a class that inherits the SpreadsheetProviderBase class:

   C#

   using Telerik.Web.UI;
   using Telerik.Web.Spreadsheet;
   
   public class SpreadsheetDataBaseProvider : SpreadsheetProviderBase
   {
   
   }
   

   VB

   Imports Telerik.Web.UI
   Imports Telerik.Web.Spreadsheet
   
   Public Class SpreadsheetDataBaseProvider
       Inherits SpreadsheetProviderBase
   
   End Class
   

2. In the custom class you should implement the SaveWorkbook and GetSheets methods:

   C#

   public override void SaveWorkbook(Workbook workbook)
   {
       ...
   }
   
   public override List<Worksheet> GetSheets()
   {
       var result = new List<Worksheet>();
       ....
       return result;
   }
   

   VB

   Public Overrides Sub SaveWorkbook(workbook As Workbook)
       ...
   End Function
   
   Public Overrides Function GetSheets() As List(Of Worksheet)
   
       Dim result = New List(Of Worksheet)()
       ....
       Return result
   
   End Function
   

JavaScript keeps the dates as interegers and in the save method, the dates would would be received as integers, not DateTime objects. To convert the integer to a date on the server, the following approach can be used:

**C#**

    public override void SaveWorkbook(Workbook workbook)
    {
        ...
            var date = new DateTime(1900, 1, 1);
                // dateValue is the Cell's string value parsed as an integer
                var dateFromDateValue = date.AddDays(dateValue - 2);
        ...
    }

**VB**

    Public Overrides Sub SaveWorkbook(workbook As Workbook)
        ...
            Dim date = New DateTime(1900, 1, 1)
        ' dateValue is the Cell's string value parsed as an integer
        Dim dateFromDateValue = date.AddDays(dateValue - 2)
        ...
    End Function

1. Provide the RadSpreadsheet control with the newly created custom provider at the Page_Load in the following manner:

   C#

   protected void Page_Load(object sender, EventArgs e)
   {
       SpreadsheetDataBaseProvider provider = new SpreadsheetDataBaseProvider();
       RadSpreadsheet1.Provider = provider;
   }
   

   VB

    Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load
           Dim provider As SpreadsheetDataBaseProvider = New SpreadsheetDataBaseProvider()
           RadSpreadsheet1.Provider = provider
       End Sub
   

You can investigate the entire setup and test the behavior of the RadSpreadsheet with Custom Database Provider in this Code Library: Custom Database Provider for RadSpreadsheet Code Library.

See Also

• How to iterate all cells and rows in Spreadsheet properly on the server-side