Possible to change bounds of map based on what is selected by LayerControl

[galewis2]

In short, is it possible to have Folium generate a map whereby the map is zoomed and/or bounding box changed when the user changes the layer?

I'm currently using FeatureGroups added to the map, overlay off (so one layer can be viewed at a time). I would like to automatically have the map zoom to the featuregroup extent when selected.

Thanks!

[Conengmo]

Hi @galewis2 , I don't think this is currently implemented in folium. It sounds like a nice feature. If someone wants to whip up a PR for this I'd gladly review it.

Some thoughts:

• For starters we could apply this to the FeatureGroup class.
• I suppose this doesn't apply to tile layers because they cover the whole map.
• Does this apply to other classes as well? I'd rather not make it too complicated.
• The Leaflet FeatureGroup class has a get_bounds method we could use.
• The map has a method to fit to bounds. Haven't tried this approach though.

[galewis2]

Duly noted, I had a look at the code and it's not too bad. I have some experience with Jinja2 and way back used Leaflet quite a bit.

As a first attempt, I'm considering doing this as a boolean on LayerControl and drop in a map.on action when BaseLayer change as a first step. Unfortunately that only covers overlays, may need a bit more work to cover featuregroups.

That way if a FeatureGroup is specifically excluded from LayerControl, it won't have those properties as they're irrelevant to zoom to function

[galewis2]

@Conengmo I assume this would be best placed in a plugin as it's not core Leaflet functionality?

[Conengmo]

You don't have to move it to a plugin, because it uses only Leaflet native stuff. Plugins are for things that use other external resources, such as Leaflet plugins.

Let's take the rest of the discussion to the PR.