Replacing an Excel File DataSource

Sometimes dashboards are created using Excel files stored in the cloud as a data source for its visualizations.

When embedding the Reveal SDK in your application, you can replace these cloud-based files with files stored in a local directory at runtime.

Step 1 - Create a class that implements IRVDataSourceProvider. This class will perform the actual replacement of the Excel files.

public class MyDataSourceProvider : IRVDataSourceProvider
{
    public Task<RVDataSourceItem> ChangeVisualizationDataSourceItemAsync(RVDashboardFilter filter, RVDataSourceItem dataSourceItem)
    {
        throw new NotImplementedException();
    }

    public Task<RVDataSourceItem> ChangeDashboardFilterDataSourceItemAsync(RVDashboardFilter filter, RVDataSourceItem dataSourceItem)
    {
        throw new NotImplementedException();
    }
}

The ChangeVisualizationDataSourceItemAsync method of this class returns the RVDataSourceItem that the visualization will use to get its data. By modifying the RVDataSourceItem item that is provided as an argument in the ChangeVisualizationDataSourceItemAsync method, you can change which Excel file get your data from.

Step 2 - Set the RevealSdkSettings.DataSourceProvider to an instance of the class that implements IRVDataSourceProvider

RevealSdkSettings.DataSourceProvider = new MyDataSourceProvider();

Example: Replacing an Excel File Data Source

In this example, we are replacing a data source item that is using a cloud-based Excel file named "Sales Cloud Excel File" with a local Excel file named "SalesLocalExcelFile.xlsx".

First, we check the incoming RVDataSourceItem to see if it is a RVExcelDataSourceItem. If it is, then we get the existing RVDataSourceItem.ResourceItem and check its Title property. If the title is "Sales Cloud Excel File" then we will create a new RVLocalFileDataSourceItem and set the Uri to the location of the new local Excel file. After we set the title of the local Excel file data source item, we replace the RVExcelDataSourceItem.ResourceItem with our newly created RVLocalFileDataSourceItem.

public Task<RVDataSourceItem> ChangeVisualizationDataSourceItemAsync(RVVisualization visualization, RVDataSourceItem dataSourceItem)
{
    if (dataSourceItem is RVExcelDataSourceItem excelDataSourceItem)
    {
        var resourceItem = excelDataSourceItem.ResourceItem as RVDataSourceItem;
        if (resourceItem.Title == "Sales Cloud Excel File")
        {
            var localItem = new RVLocalFileDataSourceItem();
            localItem.Uri = "local:/SalesLocalExcelFile.xlsx";
            localItem.Title = resourceItem.Title;

            excelDataSourceItem.ResourceItem = localItem;
        }
    }

    return Task.FromResult(dataSourceItem);
}