plotly legends are not interactive in arviz.

[isofer]

one of the feature that plotly supports is to be able to interact with the legend. You can isolate traces by double-clicking them or turn a trace on/off by clicking on them in the legend. For some reason this ability was lost in arviz.
To see it you can simply check the docs. you can see that clicking on the legend doesn't affect the plots, compared to clicking on native plotly legends (for instance, on this page).

[OriolAbril]

This is related to #68. I agree it would be very nice to add, but I think relying on the default behaviour would be more annoying than actually helpful. Most ArviZ plots are more complex than the ones shown in the plotly docs so having one entry per trace/visual wouldn't be really useful. If you look at the videos in #68, I generated an interactive legend for the model, which also gets the color mapped to it. If we went with the default approach shown in plotly's docs we'd end up with a huge legend with at least one entry per visual and model (kde line, ci line, point estimate dot and point estimate text times the two models), maybe even duplicating this times the number of subplots.

We can use the fact that plotcollection allows for arbitrary arguments as aesthetics to add legendgroup property by default, but always making sure it can be modified by the users to add the interactivity using a different grouping strategy (for example by variable instead of model or by visual element to hide ci and point estimates and leave only the kdes). I can imagine uses for all 3 of these example groupings yet I can't imagine a scenario where I'd want to generate the "full" legend with no grouping.

Is there any specific use case you have in mind? It will probably be easier to discuss potential default behaviours from an initial idea than interactive legends as an abstract concept.

[isofer]

Sorry, I think my suggestion was not clear. I wasn't suggesting that every trace should appear in the legend. I was suggesting that if something appear in the legend it would be interactive by default.