Click-drag zooming does not trigger a plotly_relayout event for 'scattergl'

[halfs13]

As shown in this JSfiddle, for type: 'scatter' using the click-drag zoom triggers the event; for type: 'scattergl' doing the same does not trigger the event.

[etpinard]

You're correct. Zooming in on a scattergl graph does not emit plotly_relayout.

@halfs13 Zooming in on gl and svg graphs work differently at the moment.

In svg, zooming modifies the xaxis and yaxis ranges to selection box and redraw the graph with the help of Plotly.relayout.

In gl, that operation would take much longer to perform; we try to shortcut most of the drawing logic. In other words, zooming does not call Plotly.relayout.

We could still emit a plotly_relayout event when zooming on a gl graph so that users could use hook in custom functionality, but wouldn't that be an abuse of language?

We could solve the problem by adding a plotly_zoom event to be emitted on both svg and gl zooms.

[halfs13]

plotly_zoom would be very helpful. And either the same event or something similar to trigger when panning using the pan tool.

[kevintc]

+1, I just stumbled on this issue, I'm trying to implement a callback when the user zooms on a scattergl graph and couldn't make it work. I understand why now :)

Is there any news regarding this implementation ? (either plotly_relayout or plotly_zoom would be nice). Is there any callback available when using scattergl ?

[etpinard]

done in #466