Column widths incorrectly calculated based on previous rowData when using autoSize in AgGrid

[petar-qb]

trafficstars

Description

I'm using AgGrid component with columnSize="autoSize" configuration. When the data filter value is changed, the grid column widths are calculated based on the previous instead on the latest rowData.

It seems like the DashAgGrid.updateColumnWidths() (and the inner gridApi.autoSizeAllColumns(skipHeader)) are called before the most recent rowData is set.

Expected behavior would be that the column widths are always aligned with the latest rowData.

---

How to Reproduce

Package version: dash-ag-grid==31.2.0

After running the code below, adjust the range slide filter as it's showed in the screen recoding (video below the code section):

import dash
from dash import dcc, html, Input, Output, callback
import dash_ag_grid as dag
import pandas as pd


# Initialize the Dash app
app = dash.Dash(__name__)


# Sample data
df = pd.DataFrame({
    'Column 1': [1, 2, 3, 4, 5, 6],
    'Column 2': ['A', 'B', 'C', 'VeryLongStringInputCell_VeryLongStringInputCell_VeryLongStringInputCell', 'D', 'E'],
    'Column 3': [10.5, 20.1, 30.2, 40.3, 50.4, 60.5],
})

# Layout
app.layout = html.Div([
    html.H1('Grid Page'),
    html.Div(id="outer_div_grid_id"),
    dcc.RangeSlider(id="filter_column_1_dropdown", min=1, max=6, step=1, value=[1, 6]),
])


@callback(
    Output("outer_div_grid_id", "children"),
    Input("filter_column_1_dropdown", "value"),
)
def update_outer_grid(dropdown_value):
    df_filtered = df[df["Column 1"].between(dropdown_value[0], dropdown_value[1], inclusive="both")]

    return [dag.AgGrid(
        id='grid_id',
        columnDefs=[{'field': col} for col in df.columns],
        columnSize="autoSize",
        rowData=df_filtered.to_dict('records'),
        defaultColDef={'resizable': True},
    )]


if __name__ == "__main__":
    app.run_server(debug=True, port=8051)

https://github.com/user-attachments/assets/ffa449c4-4219-42ef-bf0e-a152449b0c58

[BSd3v]

Hello @petar-qb,

This probably works in a previous version, however, in the AG Grid update between these two versions, the rowData started updating asynchronously. Due to this, it broke selectedRows and also this.

However, it is important to note that in dash, you are not removing the component and causing it to be fresh, you are essentially updating the component, which means the grid is already initialized, therefore triggering the columnSize when updated.

Here is a way to update it with adjusting the id and you get the expected behavior:

import dash
from dash import dcc, html, Input, Output, callback
import dash_ag_grid as dag
import pandas as pd


# Initialize the Dash app
app = dash.Dash(__name__)


# Sample data
df = pd.DataFrame({
    'Column 1': [1, 2, 3, 4, 5, 6],
    'Column 2': ['A', 'B', 'C', 'VeryLongStringInputCell_VeryLongStringInputCell_VeryLongStringInputCell', 'D', 'E'],
    'Column 3': [10.5, 20.1, 30.2, 40.3, 50.4, 60.5],
})

# Layout
app.layout = html.Div([
    html.H1('Grid Page'),
    html.Div(id="outer_div_grid_id"),
    dcc.RangeSlider(id="filter_column_1_dropdown", min=1, max=6, step=1, value=[1, 6]),
])


@callback(
    Output("outer_div_grid_id", "children"),
    Input("filter_column_1_dropdown", "value"),
)
def update_outer_grid(dropdown_value):
    df_filtered = df[df["Column 1"].between(dropdown_value[0], dropdown_value[1], inclusive="both")]

    return [dag.AgGrid(
        id=f'grid_id{dropdown_value}',
        columnDefs=[{'field': col} for col in df.columns],
        columnSize="autoSize",
        rowData=df_filtered.to_dict('records'),
        defaultColDef={'resizable': True},
    )]


if __name__ == "__main__":
    app.run_server(debug=True, port=8051)

or you can use a chained callback:

import dash
from dash import dcc, html, Input, Output, callback
import dash_ag_grid as dag
import pandas as pd


# Initialize the Dash app
app = dash.Dash(__name__)


# Sample data
df = pd.DataFrame({
    'Column 1': [1, 2, 3, 4, 5, 6],
    'Column 2': ['A', 'B', 'C', 'VeryLongStringInputCell_VeryLongStringInputCell_VeryLongStringInputCell', 'D', 'E'],
    'Column 3': [10.5, 20.1, 30.2, 40.3, 50.4, 60.5],
})

# Layout
app.layout = html.Div([
    html.H1('Grid Page'),
    html.Div(id="outer_div_grid_id", children=
             [dag.AgGrid(
        id=f'grid_id',
        columnDefs=[{'field': col} for col in df.columns],
        columnSize="autoSize",
        rowData=df.to_dict('records'),
        defaultColDef={'resizable': True},
    )]),
    dcc.RangeSlider(id="filter_column_1_dropdown", min=1, max=6, step=1, value=[1, 6]),
])


@callback(
    Output("grid_id", "rowData"),
    Input("filter_column_1_dropdown", "value"),
)
def update_outer_grid(dropdown_value):
    df_filtered = df[df["Column 1"].between(dropdown_value[0], dropdown_value[1], inclusive="both")]

    return df_filtered.to_dict('records')

@callback(
    Output("grid_id", "columnSize"),
    Input("grid_id", "rowData"),
)
def update_size(_):
    return 'autoSize'


if __name__ == "__main__":
    app.run_server(debug=True, port=8051)