dash_table.DataTable - Determining which rows have changed

Dash Python
1

When we make table editable, is there a way we can know which rows have changed?

tried using data & data_previous to compare and find out which rows have changed, but there is an issue with that, so if i am editing multiple rows assuming 3 rows, row number 1, 10 & 15 in the same sequence.

data and data previous have difference only in the last edited row. so data_previous will have row 1 and row 10 with the updated number, and data will have all 3 rows updated 1,10 & 15. which is why i am not able to get the exact differences.

2

Hm, this should work and I’ve used this in the previous projects as the way to determine which rows have changed.

3

Something like this uses to work in dash table experiments. But this isnt.

4

@chriddyp - thanks for taking a look, let me know if you find something on this? have tried it a lot unable to get this work.

5

The answer took a little too long, however, it’s never too late.

This is the best way I found

@app.callback(
    Output('div-result', 'children'),
    [Input('my-table', 'data'),
     Input('my-table', 'columns')],
     [State('my-table', 'active_cell')], prevent_initial_call=True
)
def update_tol_db(rows, columns, cell):
    if(rows == None or columns == None or cell == None):
        raise PreventUpdate
    print(rows[cell['row']])
    raise PreventUpdate

I’m using the updated row to update my database, so this is why I’m not really updating the div.

6

Seems like it works well with a single row. What is about multiple rows?

I tried to use selected_cells and data for extracting changed data, but selected_cells returns only one row on the paste event as if it would be only active cell.

7

I ended up with detecting the changed rows by comparing data attribute and data queried from a database, instead of previous_data attribute or workaround with selected_cells.

It’s puts some overhead on performance but works as expected, no unsolvable Datatable bugs.