Reporting Services 2005 doesn’t allow you to selectively disable export formats for your reports. You can disable export formats for the whole server, but this is a bit useless in a shared environment. For my current client, we wanted to disable XML, Tiff and “web archive” export on all of our reports, but not affect any other reporting applications deployed on the server.

Our reports consist of custom parameter pages followed by a report view page onto which we’ve dropped a ReportViewer control. When the page loads, we programatically set the ReportViewer’s server URL, report path, and parameters. We’re doing this to ensure users are requesting reports for data that they’re allowed to see and not tricking us into revealing other users’ data.

Whilst there’s no official way to disable export formats on an individual report, a little bit of exploration using Reflector reveals that the ReportViewer contains a ServerReport that acts as a proxy between the control and the Reporting Services web service. The ServerReport allows you to list rendering extensions—these guys do the hard work of actually exporting in each format—but it doesn’t allow you to set the visibility of an extension. Reflection to the rescue!

The following code sample turns off XML, Tiff, and “web archive” export for a particular ReportViewer or ServerReport:

using System.Reflection;
using Microsoft.Reporting.WebForms;
using Microsoft.SqlServer.ReportingServices2005.Execution;

namespace MyProject
{
    public class ServerReportDecorator
    {
        private readonly ServerReport serverReport;

        public ServerReportDecorator(ReportViewer reportViewer)
        {
            this.serverReport = reportViewer.ServerReport;
        }

        public ServerReportDecorator(ServerReport serverReport)
        {
            this.serverReport = serverReport;
        }

        public void DisableUnwantedExportFormats()
        {
            foreach(RenderingExtension extension in serverReport.ListRenderingExtensions())
            {
                if(extension.Name == "XML" || extension.Name == "IMAGE"
		                           || extension.Name == "MHTML")
                    ReflectivelySetVisibilityFalse(extension);
            }
        }

        private void ReflectivelySetVisibilityFalse(RenderingExtension extension)
        {
            FieldInfo info = extension.GetType().GetField("m_serverExtension",
                                                          BindingFlags.NonPublic
							| BindingFlags.Instance);
            if (info != null)
            {
                Extension rsExtension = info.GetValue(extension) as Extension;
                if(rsExtension != null)
                {
                    rsExtension.Visible = false;
                }
            }
        }
    }
}

I really hope Microsoft includes this functionality in the next release of Reporting Services. It would be really quite simple to include it in the graphical report designer and avoid this nasty reflection hack entirely. At the very least, the sealed RenderingExtension class could have a mutable “Visible” property, rather than the read-only property it has now.