Show loading indicator while export file is generating

[Nikolay]

Hi

When user clicks "Export" button it takes about 10 minutes before download starts for grid with 300 000 records. Is there a way to display a loading indicator at least while export file is generating?

 

[Martin Bechev]

Hello Nikolay,

Implementing a Loading indicator would be ideal in this case, but notifying the user when the export operation is complete is troublesome, as we don't get enough feedback from the browser.

There are three distinct operations that make up the export:

1. Collecting and processing the data. The excelExport is fired at the end of this task.
   
2. Generating the MS Excel Document and encoding it as Base64 string. No event is fired at this stage.
   
3. Saving the exported document directly in the browser or by using a server proxy. No event is fired at this stage.
   

The end of step 3 is ideally when we want to notify the user. However, there's no browser event that we can hook to.

Saving the file is an asynchronous operation that does not report back to the main thread. Maybe the server-side proxy can be extended to provide a status end-point that blocks while the request for a particular user completes. I am afraid that we don't have any specific examples to share.

Regards,
Martin
Progress Telerik