Hello Michael,

Thank you for getting back to us and pointing this out. You are correct—directly modifying dataSource.transport.data is not documented and is not the recommended or supported way to update a Kendo UI DataSource. This approach may also break in future releases or cause issues with TypeScript integration.

Recommended Way to Update DataSource Data

• To resolve the issue, you can directly use the .setDataSource() method of the Grid. I have prepared a working sample for your convenience:
  https://dojo.telerik.com/bIRIrEAK/5 

• If you are using a custom transport (for example, with AJAX), make sure your transport.read function always returns the latest data. The .read() method should then fetch new data from your source, not restore any old data.

• Avoid using .refresh() or .read() with a local DataSource unless you have set up a custom read transport that returns the current data. Otherwise, these methods may revert the DataSource to its initial state.

You can find more details in the official documentation:

- https://www.telerik.com/kendo-jquery-ui/documentation/api/javascript/ui/grid/methods/refresh 
- https://www.telerik.com/kendo-jquery-ui/documentation/api/javascript/ui/grid/methods/setdatasource 
- https://www.telerik.com/kendo-jquery-ui/documentation/api/javascript/data/datasource/configuration/data 
https://www.telerik.com/kendo-jquery-ui/documentation/api/javascript/data/datasource/configuration/transport.read 
- https://www.telerik.com/kendo-jquery-ui/documentation/api/javascript/data/datasource/configuration/transport.read#transportreaddata 
- https://www.telerik.com/kendo-jquery-ui/documentation/api/javascript/data/datasource/configuration/transport.read#transportreadcache 

I hope this will prove helpful.

Regards,
Eyup
Progress Telerik

Hello Michael,

To ensure the locally bound data source does not restore the original data, you can set the transport.data to an empty array:

• https://dojo.telerik.com/@pmilchev/UVEPaxID 

•   // clear the data
    dataSource.data([])
    dataSource.transport.data = [];

Regards,
Peter Milchev
Progress Telerik