I'm currently implementing a web map application (OpenLayers 5.3, Tomcat 8/GeoServer 2.14.0, Apache)
There is a rising number of vector layers coming from different external WFS services. Using WMS service is not enough, application is supposed to do more than just showing the data.
For almost every vector layer, I make as many "sublayers" as the number of values an attribute (1 in general, sometimes 2...) can have.
The idea is to limit as much loading time as possible but allowing availability of a lot of data (and "subdata").
=> instead of displaying a map with a legend, you can imagine a legend (it already uses a LayerSwitcher) in which there would be a checkbox for each item (or even subitems) in the legend (if you follow my thoughts) because it needs features that can be used for all kinds of topographic processing, not just images.
So, my question is :