I'm building a layer tree and I would like it to be updated automatically when the page is loaded with layer that are in a specific workspace on GeoServer.
In my layer tree I have a group containing background layers such as Bing satellite and OSM, and another group that will contain the GeoServer layers.
How can I request the layers from the workspace and add them automatically?
You don't have that (yet) on GeoExt 3. Meanwhile, you might check another smaller project focused on managing layers, called extjs_ol3_layercontrol. It is also written in ExtJS.
Check the blog and the github.
If you add the Geoserver capabilities URL (something like http://localhost:8080/geoserver/wms?service=wms&version=1.3&request=GetCapabilities) to ol.control.LayerControl you can add your layers from it.
