1. Home
  2. Forum
  3. Blazor
  4. Excel Export throws NRE when both Virtualization & Grouping are enabled

Excel Export throws NRE when both Virtualization & Grouping are enabled


Hello,

Since we are experimenting a lot with virtualization in Datagrids, we encountered another issue that we cannot seem to find a solution.
This issue is also similar/extends this one

Assume that the Grid is bound to a local list
  • Virtualization Enabled
  • Excel export behaviour ==> Even if we override DataSource in ExcelExportProperties, only the current page size will be exported
  • This means that Grid's DataOperations apply. (.Take(pagesize) from virtualization) (Already reported to link above)
  • Grouping by a column and exporting to excel throws NRE (new issue)
Assume now that the Grid is bound to a datasource through a Custom Adaptor (again, a list for the sake of simplicity) 
  • Virtualization works great, grouping, filtering, sorting all works great.
  • Excel export behaviour ==> Overriding DataSource in ExcelExportProperties, now exports the whole datasource, not only the pagesize.
  • This means that Grid's DataOperations DO NOT apply. (Extends reported issue from link above)
  • Grouping by a column and exporting to excel throws NRE (new issue)

The NullReferenceException stacktrace

   at Syncfusion.Blazor.Grids.Internal.ExportHelper`1.<DataProcess>d__0.MoveNext()


If we disable virtualization (and enable paging) in both cases, excel export works with grouped data.

I read somewhere in these forums (for a different platoform though) that when exporting, it compares internally the columns and if they are not found in the datasource it returns null. This makes sense because when grouping, the column structure changes.

I am attaching a sample with two pages (Index, Index2) demonstrating the described behaviour in both cases.

Best Regards,
Chris





Attachment: Serversample_ExcelExport_19d89024.7z

1 Reply
RS Renjith Singh Rajendran Syncfusion Team October 30, 2020 01:06 PM UTC

Hi Christos, 

Greetings from Syncfusion support. 

Query 1 : Even if we override DataSource in ExcelExportProperties, only the current page size will be exported 
We have considered it as a bug and logged the defect report “Unable to export all the records when virtualization is enabled” for the same. Thank you for taking the time to report this issue and helping us improve our product. At Syncfusion, we are committed to fixing all validated defects (subject to technological feasibility and Product Development Life Cycle ) and including the defect fix in our upcoming patch release which is expected to be rolled out by the end of November 2020. 
    
You can now track the current status of your request, review the proposed resolution timeline, and contact us for any further inquiries through this link.    

Query 2 : Grouping by a column and exporting to excel throws NRE (new issue) 
Currently we don’t have support to export Grid to excel when enabling Grouping with Virtualization in Grid. But we have considered this as a feature improvement and logged a task “Provide ExcelExport support for Grid with Virtaulization and Grouping” for the same. This will be implemented in any of our upcoming releases. 

You can now track the current status of your request, review the proposed resolution timeline, and contact us for any further inquiries through this link.    

Please follow up on the corresponding feedbacks for further updates on this and get back to us if you need further assistance. 

Regards, 
Renjith Singh Rajendran 


Loader.
Up arrow icon