Mix of Scatter and Scattergl - Scattergl is always on top

[wdobbels]

A typical use case for me is to have a bunch of scatterpoints (need Scattergl), and then fit a line through them (ideally with normal Scatter). However, no matter the order of the traces, Scattergl always seems to end on top (and hence the line disappears below the scatter points). Ideally, the order of the traces should be retained (no matter if it's a Scatter or Scattergl). Even better would be a zorder parameter (as in matplotlib), where we don't need to worry about the order in which we add the traces to the data.

Here's some code to reproduce the bug:

import plotly.offline as py
import plotly.graph_objs as go

trace_scatter = go.Scattergl(x=[1, 2, 3, 4], y=[1, 2, 3, 4], mode='markers')
trace_line = go.Scatter(x=[1, 4], y=[1, 4], mode='lines')
# line trace is placed last, so should end up top - but it doesn't
data = [trace_scatter, trace_line]
py.iplot(data)

If Scattergl is replaced by Scatter, the line is correctly drawn up top. I tested this in offline mode but assume the same is true in online mode. I'm new to plotly so I don't know enough about its inner workings to do a pull request right now (if really needed, with some pointings in the right direction, I could take a look).

[jonmmease]

Hi @wouterdobbels, thanks for the suggestion.

See plotly/plotly.js#3748 for a recent discussion of this in the plotly.js project. Feel free to chime in there if you have API suggestions.

[gvwilson]

Hi - we are currently trying to tidy up Plotly's public repositories to help us focus our efforts on things that will help users most. Since this issue has been sitting for several years, I'm going to close it. If it's still a concern, we'd be grateful if you could open a new issue (with a short reproducible example if appropriate) so that we can add it to our backlog. Thanks for your help - @gvwilson