Handsontable: how to prevent the table from refreshing when a value changes

Question

first post to StackOverflow, though I've been finding great tips for a few years here. Hope to resolve a vexing problem with handsontable.

I have an application that presents a handsontable instance with several columns whose content/format is dependent upon the value in a cell in another column. I determine the content and format of the dependent cells by way of a database query and server-side processing, the results of which are sent back to handsontable for processing in the afterChange function.

My problem is that whenever the user updates one cell in the table, ALL cells blink while the code laboriously reconsiders the formatting for ALL cells in the table. The preferred behavior would be to ONLY update the cells for which the formatting has changed, i.e., that small set which is dependent on the value that changed in the first cell. It's only these dependent cells whose contents are being changed anyway. Why redraw the WHOLE table??

I have searched and search here and elsewhere, and the closest to an answer I could find is that this is the intended behavior for the table. I don't agree...when the table is anything larger than 10 rows, the updating process is painfully slow and distracting to the user.

Any suggestions? I'm open to directly editing the handsontable js code, but would prefer to flip some flag I'm unaware of if possible.

Thanks all!

Answer 1

afterChange fire only one time for the cell you just updated (documentation example).
Your problem might come from an afterChange "chain reaction". The first afterChange modifies one or more related cells, triggering others afterChange and so on. If that's the problem, you can put a filter on the source parameter.

Another solution could be to work on a copy of the data to do your updates (see data binding), and once everything is fine, inject it back on the table with loadData, and ignore the loadData source in the afterChange callback.

Finally, if you still have some performance issues, you can check the performance tips, and remove any option that might slow your table (example with columnSorting)

(sorry I can't use comments to identify precisely from where your issue come...)