Batch property updates fail

Python version: 3.8 ipyleaflet version: 0.13.1 used in a vanilla Jupyter notebook

A question, not a bug: I have a layer group of ~3000 polylines, which I need to re-style in response to user input. I’m only learning ipyleaflet, so I do it naïvely in a loop:

for obj_id, obj_data in data:  # len(data) > 3000
    line: ipyleaflet.Polyline = self._obj_lines[obj_id]

    if obj_data["x"] > user_input:
    	line.color = 'red'
    	line.weight = 10
    else:
    	line.color = 'black'
    	line.weight = 1

Sometimes (not always) these updates get stuck half-way (see the GIF; no line is supposed to stay blue) and nothing short of recreating the whole map object helps, certainly not re-executing the update code.

My guess is that this approach generates too many individual update messages between the kernel and the front-end which leads to some communication breakdown or state discrepancy. If that is correct, what are the better options from the Python side?

• is it possible to manually trigger “state synchronization” to ensure update completion?
• can/should I manually batch updates?
• should I switch to a GeoJSON layer? (GeoData doesn’t seem to support dynamic styling, if I’m correct)

[martinRenou]

This looks like a different issue. Would you mind opening another issue and provide some code to reproduce?

[martinRenou]

This piece of code should work indeed. The following PR should fix it: #658. I tried locally and could see it working but if you have time to try it out too that would be greatly appreciated 😃