A service enabling you to perform custom operations with a Document Viewer's currently opened document.
You can create a DocumentOperationService class descendant, and override its DocumentOperationService.CanPerformOperation method to define which operations are permitted and the DocumentOperationService.PerformOperation method to perform the required actions. To register your custom class, use the DefaultWebDocumentViewerContainer.Register<T, TImpl> method at the application startup.
On the client side, call the ASPxClientWebDocumentViewer.PerformCustomDocumentOperation method to send the request to perform the required document operation.
For a code sample, refer to Web Document Viewer - How to send a report via Email from the client side.