BarChart not displayed under certain conditions

[engdan77]

Question

I am still quite unexperienced with this package so hopefully I am not missing anything too obvious.
There is this things that trips me and wondering if someone possibly could shed some light on to better understand..?

It is while use the BarChart (inside a container) widget placed within a Column with another Row like:
page.add(ft.Column([ft.Row([ft.Container(chart)])]))

... interestingly, replacing the chart with a Text instead does work like:
page.add(ft.Column([ft.Row([ft.Text('Foo Bar')])]))

I've tried a few different samples (in the code sample) and been unable to find a good answer to this.
.. or should this be considered a bug?

Code sample

import flet as ft


def main(page: ft.Page):
    chart = ft.BarChart(
        bar_groups=[
            ft.BarChartGroup(
                x=0,
                bar_rods=[
                    ft.BarChartRod(
                        from_y=0,
                        to_y=40,
                        width=40,
                        color=ft.Colors.GREEN,
                        # tooltip="Apple",
                        border_radius=0,
                    ),
                ],
            ),
            ft.BarChartGroup(
                x=1,
                bar_rods=[
                    ft.BarChartRod(
                        from_y=0,
                        to_y=100,
                        width=40,
                        color=ft.Colors.BLUE,
                        # tooltip="Blueberry",
                        border_radius=0,
                    ),
                ],
            ),
            ft.BarChartGroup(
                x=2,
                bar_rods=[
                    ft.BarChartRod(
                        from_y=0,
                        to_y=30,
                        width=40,
                        color=ft.Colors.RED,
                        # tooltip="Cherry",
                        border_radius=0,
                    ),
                ],
            ),
            ft.BarChartGroup(
                x=3,
                bar_rods=[
                    ft.BarChartRod(
                        from_y=0,
                        to_y=60,
                        width=40,
                        color=ft.Colors.ORANGE,
                        # tooltip="Orange",
                        border_radius=0,
                    ),
                ],
            ),
        ],
        border=ft.border.all(1, ft.Colors.GREY_400),
        left_axis=ft.ChartAxis(
            labels_size=40, title=ft.Text("Fruit supply"), title_size=40
        ),
        bottom_axis=ft.ChartAxis(
            labels=[
                ft.ChartAxisLabel(
                    value=0, label=ft.Container(ft.Text("Apple"), padding=10)
                ),
                ft.ChartAxisLabel(
                    value=1, label=ft.Container(ft.Text("Blueberry"), padding=10)
                ),
                ft.ChartAxisLabel(
                    value=2, label=ft.Container(ft.Text("Cherry"), padding=10)
                ),
                ft.ChartAxisLabel(
                    value=3, label=ft.Container(ft.Text("Orange"), padding=10)
                ),
            ],
            labels_size=40,
        ),
        horizontal_grid_lines=ft.ChartGridLines(
            color=ft.Colors.GREY_300, width=1, dash_pattern=[3, 3]
        ),
        tooltip_bgcolor=ft.Colors.with_opacity(0.5, ft.Colors.GREY_300),
        max_y=110,
        interactive=True,
        expand=True,
    )

    # Working - COLUMN with another COLUMN, and container inside
    # page.add(ft.Column([ft.Column([ft.Container(chart)])]))

    # Working - COLUMN with a ROW, and container inside, but we use expand=True
    # page.add(ft.Column([ft.Row([ft.Container(content=chart, expand=True)])]))

    # Working - COLUMN with a ROW, and chart inside but not within a container
    # page.add(ft.Column([ft.Row([chart])]))

    # Working - COLUMN with a ROW, and text inside but not within a container
    # page.add(ft.Column([ft.Row([ft.Text('Foo Bar')])]))

    # Not working - COLUMN with a ROW, and container inside
    page.add(ft.Column([ft.Row([ft.Container(chart)])]))


if __name__ == "__main__":
    ft.app(main)

Error message

No widget seen within the window

------------------------------------------------------

• I have searched for answers to my question both in the issues and in previous discussions.

[ndonkoHenri]

May I please know which Flet version you are using?

[engdan77]

I've now tested both using Flet 0.27.6 -> and Flet 0.28.3 and it seems to me the same behaviour there.