Channel set does not clear list properly

[parente]

Using jupyter-declarativewidgets==0.4.2. Might be fixed on master?

To start slaIDs.items is an array in a channel with engagementChannel as its ID. Then, in the JS console we see:

// no event fires
$('#engagementChannel').get(0).set('slaIDs.items', [])
undefined

// and the reset to empty array doesn't take effect
$('#engagementChannel').get(0).get('slaIDs.items')
[0, 1]

// if we change the value in the array, it works
$('#engagementChannel').get(0).set('slaIDs.items', [3])
jupyter-widget-behavior.html:126 Urth.JupyterWidgetBehavior send - sending message Object {event: "change", data: Object}
urth-core-function.html:430 urth-core-function handling change to sla_ids
urth-core-function.html:346 urth-core-function _onParameterChange sla_ids [3]
undefined

// now if we set to empty array, it also works (huh?)
$('#engagementChannel').get(0).set('slaIDs.items', [])
jupyter-widget-behavior.html:126 Urth.JupyterWidgetBehavior send - sending message Object {event: "change", data: Object}
urth-core-function.html:430 urth-core-function handling change to sla_ids
urth-core-function.html:346 urth-core-function _onParameterChange sla_ids []

[purdrew]

How is slaIDs.items initialized or being set prior to this JS code?

[purdrew]

@parente Can you give me a little more information around the initial setup that makes this situation reproducible. I can see a possible explanation for the initial .set not clearing the array but have not reproduced in the notebook. I'm guessing there was some Python code that had initialized the Python side of the channel data for slaIDs.items to [0, 1] but when I try to do something similar I can't reproduce the issue.

[parente]

Sorry for not responding last time you asked. I'll try to create a small reproducible example notebook sometime this week.

[parente]

Appears to be fixed in 0.5.0dev0. Probably fixed by #249.