How to change the grand total value from UI?

Hello, Ravi,
 
Thank you for writing to us.
 
1-2. About providing a custom Grand Total value or changing the formula for calculating the Grand Total:
We would like to kindly explain that using a different aggregation for calculating the Grand Total is not supported at the moment.
We have added this request to our customer's wishlist and we will inform you in case of any changes. 

However, it is possible to provide a custom Grand Total value via the custom data source API approach released in the new major release version 2.8 of Flexmonster.
This approach greatly improves the performance and provides full control over how the data is processed. This means that now it is possible to implement your own server-side connector to the database or any data source and feed the data into Flexmonster already in the aggregated form.
 
Please see the following guides for more information:

• What the Custom Data Source API has to offer.
• Introduction to the Custom Data Source API.
• A sample implementation of the Custom Data Source API approach with Node.js.
• A sample implementation of the Custom Data Source API approach with .Net Core.
• How to implement your own implementation of the Custom Data Source API approach.

 
3. About hiding the Grand Total value for a specific field:
Hiding specific Grand Total cell values is possible by using the customizeCell() API call.
Please see the following JSFiddle example we have prepared for you.
In the provided JSFiddle, the Grand Total for "Discount" is hidden.

Please let us know if this helps and if you have further questions that we can help with.
Looking forward to your reply.
 
Kind regards,
Vera