Support multiple layers in a map visualization

Problem

As we add more visualization types, it will be useful to pull in multiple visualization layers into the same visualization. To do this, we’ll need an API to addLayer to an existing visualization.

For example, users may want to create a heatmap visualization at low zoom levels, and a graduatedCircle visualization at high zoom levels.

A user may also want to add two or more layers to a map from different data sources.

Implementation

• Add minZoom and maxZoom properties to each viz type
• Create addLayer function to add a layer to an existing viz object

[nahidpervez]

@ryanbaumann Any idea when this feature will be released?

[akacarlyann]

@bchowTWC and @carsnwd I’ve been experimenting with this too though I don’t have image or raster layers worked in yet. It’s kind of wrapped up in generating layer styles in Python, so still needs some adjustments. I can clean up what I have and share if you’re interested 😃

@carsnwd thanks for opening this issue with your outline, btw!! It really got me thinking 😃