[BUG]: FigureWidget: layout.shapes not updated after drawing a path in JupyterLab

[eugenekwaNeuromics]

Description

When attempting to enable draw closed paths on a plotly.graph_objects.FigureWidget, I noticed that there was an issue when attempting to delete the existing drawn paths. It seems that while fig.layout.to_plotly_json().get("shapes") is able to detect the path drawn, this information is not relayed to fig.layout.shapes. This can be fixed by manually editing fig.layout.to_plotly_json().get("shapes"), plugging it into fig.layout.shapes, and then deleting. The manual edits are to remove the <object object at 0x000001BFE6411440> that is assigned to both "name" and "legendwidth".

Steps to reproduce

import plotly.graph_objects as go
import ipywidgets as widgets
from IPython.display import display

fig = go.FigureWidget(
    go.Heatmap(
        z=[[1, 2], [3, 4]],
        showscale=False,
    )
)

fig.update_layout(
    dragmode="drawclosedpath",
    newshape=dict(
        line=dict(color="red", width=2)
    )
)

fail_clear_button = widgets.Button(description="Clear ROI (Fails)")
working_clear_button = widgets.Button(description="Clear ROI (Works)")
out = widgets.Output() 

def clear_roi(_):
    with out:
        print("layout.shapes:", fig.layout.shapes)
        print("JSON shapes:", fig.layout.to_plotly_json().get("shapes"))
        with fig.batch_update():         
            fig.layout.shapes = []
        print("After update_layout")
        print("layout.shapes:", fig.layout.shapes)
        print("JSON shapes:", fig.layout.to_plotly_json().get("shapes"))

def clear_roi_alt(_):
    with out:
        print("layout.shapes:", fig.layout.shapes)
        print("JSON shapes:", fig.layout.to_plotly_json().get("shapes"))
        json_shapes = fig.layout.to_plotly_json().get("shapes", [])
        for s in json_shapes:
            s['legendwidth'] = 0
            s['name'] =  ''
        fig.layout.shapes = json_shapes
        print("After pulling from JSON")
        print("layout.shapes:", fig.layout.shapes)
        print("JSON shapes:", fig.layout.to_plotly_json().get("shapes"))
        fig.layout.shapes = []
        print("After clearing")
        print("layout.shapes:", fig.layout.shapes)
        print("JSON shapes:", fig.layout.to_plotly_json().get("shapes"))

fail_clear_button.on_click(clear_roi)
working_clear_button.on_click(clear_roi_alt)

display(widgets.VBox([fail_clear_button, working_clear_button, fig, out]))

Notes

Python: 3.12.13
Plotly: 6.9.0
JupyterLab: 4.5.6
ipywidgets: 8.1.8
OS: Windows-11-10.0.26100-SP0

[robertclaus]

@eugenekwaNeuromics thank you for reporting!

[emilykl]

Thank you for the report @eugenekwaNeuromics! I agree this isn't expected; if the added shapes are available via fig.layout.to_plotly_json() I think it's reasonable to expect them to be available via fig.layout.shapes as well.

That said, there's a surprising amount of complexity around the various methods of accessing figure attributes in plotly.py, and even more so when FigureWidget is involved, so it's not totally surprising to me that there's a bug here.

We likely won't have the bandwidth to address this in the near future but would be happy to review a PR.

[seshan18]

I like to work on this issue

[emilykl]

Need to look closer to confirm, but I think this is a duplicate of #5309