Callback to cell not fired second time selected cells

[matthijsramlab]

I have a callback function of the selected cells properties. When the user clicks ones of the cells the callback is fired. However the second time the user clicks the same cell, the callback is not fired. Is this correct behavior or a bug?

@app.callback( Output('test', 'children'), [ Input('table', 'selected_cells'), ]) def test(selected_cells): return 'test_done'

[Marc-Andre-Rivet]

@matthijsramlab This is intended behavior. The selected_cells value does not change if the same cell is clicked repeatedly. As implemented, we are interested in the value change, not the user's individual interactions / clicks. Can you describe how this is affecting your usage scenario? Thanks.

[matthijsramlab]

Hi Marc,

Thanks for the quick reply, I use the selected cell to show the user some more information. Would be nice if the where option to set, so this would work.

[Marc-Andre-Rivet]

Ah! I see. There's no way of doing this right now. Not sure what the best approach would be as any arbitrary user interaction might be hooked up. Will reclassify as a feature request.

[alexcjohnson]

I feel like we need a distinction between a selection and a click. Selection is state, and selecting the same thing multiple times doesn't change anything, but also selection can apply to multiple cells. A click on the other hand is an action on a single cell and it's meaningful to repeat it. We have well-established ways of handling this with buttons for example - using n_clicks and dash.callback_context.triggered (which takes over from the old n_clicks_timestamp). Here it seems like we'd need two props, perhaps n_clicks (to be used as an Input) and clicked_cell (to be used as a State)

[adm78]

Our use case is basically the same as @Marc-Andre-Rivet. We have callback attached to active_cell which opens a dialog (which can be closed by the user). In order to re-open the dialog for a given cell, the user has to click another cell, then click the old cell again. Adding an n_clicks and n_clicks_timestamp attribute would be very helpful!

[matthijsramlab]

Would be great if this would be integrated 👍

[vivekvs1]

I had a similar issue. I wrote callbacks to clear the active_cell and selected_cells of the table for my code.

You might want to hook this to the modal component.

[matthijsramlab]

@vivekvs1 did not think of that, thanks!