Grouped WMS Layer

[yobiSource]

Is there an example of grouped WMS as in v1.1?
http://api.geoext.org/1.1/examples/tree.html

This greatly reduces the traffic with many layers.

[chrismayer]

As far as I can tell grouped tree layer nodes are not implemented in GeoExt 2.0.x. So there is no example showing this.

[yobiSource]

Is it easy to implement?
This is the only reason why I can not use geoext2.

[chrismayer]

To implement this as application code should be doable. You can orientate yourself at the GeoExt 1.1 code doing this: https://github.com/geoext/geoext/blob/master/lib/GeoExt/widgets/tree/LayerParamNode.js

A possible way would be to implement your own LayerContainer as a subclass of https://github.com/geoext/geoext2/blob/master/src/GeoExt/tree/LayerContainer.js with a custom LayerLoader, which detects your child layers of your group layer.