The size of a pie chart

OK "name": "series_name" is the gremlin.

This has to be the same as set in the chart config - mine is msg.topic, which exists but is empty.

So "name": "" works.

Note to self: Don't use msg.topic, use an empty string as the Series.

That is why refresh is clearing the chart, that is nothing to do with the recent mods. Switch it off.

Yes, you need to give the series a name. If you give it a name other than blank it appears in the popup tooltip on the chart. The pie chart can have multiple series in which case you have to name them of course.

So with the name and client data setting fixed is it all working as it should?

You should be able to feed in the ui_update first, or include it with the data inject (which is the same thing actually, it does the ui_update then the data).

Umm.

Yes, it is working now.

Of course I have reservations, for example to do with how the ui-chart canvas interacts with the dashboard resizing of widgets, but hard to imagine how it could behave better.

There are still some chartOptions settings that I can't get to work, work in progress.

I think there is a bug in the chart node. I am sure that doing a Restart Flows under the Deploy dropdown should clear the chart and any ui_update settings, just like a node red restart, but it doesn't. I will have to check other node types to see how they behave to see if it is a generic issue or chart node related.

[Edit] I have asked a question about what Restart Flows should do in a new post.

The options are complex, so it is possible that some won't work. Post if you get stuck so I can try to sort it out.
Also please post examples of how to do things that you think might be generally useful.