Setting msg.enabled without msg.payload results in a TypeError

[JaronrH]

Sending a component, such as the slider, a msg of just {enabled: false} results in a TypeError of "cannot read property 'toString' of undefined". This is due to the uiSlider trying to update the value via ui.js's toNumber() routine by accessing the non-existent property payload (line 48 at time of writing).

Ideally, I would think that you would want to look for msg.payload and only try to process it when it exists (if (msg.hasOwnProperty("payload")). That way, users could update the enabled/disabled state and/or the payload as they see fit as opposed to always having to pass in the current payload.

If it helps, my particular use case is that I have a slider that I want to make read-only by disabling it. I don't want to change the value though (in my case, a temperature) when I disable it.

[dceejay]

co-incidentally this is actually similar to #211 - so the proposed fix of ignoring msg without any payload (but still handling msg.enabled) would fix both

[dceejay]

So - reviewing this change - the fix has broken a lot of other things (dropping msgs without payload was bad... as the text and template nodes could also render things other that payload...)

So thought now is to catch the undefined .toString() error - and b) return undefined if it really is undefined. If set incorrectly it will return the .min value as per the info.
This will mean that setting enabled/disabled only will grey out the control correctly - but not move the slider value for example.

[JaronrH]

This may be a little too kludgy but perhaps using a flag to trigger a content update vs state update would help? Ex: If updateStateOnly is present and True, only update the other display-based properties (color, enabled/disabled, etc.) and do not update the content (or pass on the message).

[dceejay]

better fix now pushed to master as part of 2.3.10-beta

[dceejay]

re closed by fed10a5