geoserver/geoserver — pull request #102 by mbarto (2013-01-14 14:48:17+00:00)
Title: Backported WMS GetLegendGraphic support for LayerGroups

Backport of GEOS-5524 on 2.2.x

LayerGroups are supported in the following manner:
- just use a layergroup name, instead of a layer name, in the LAYER parameter to get a legend for the group
- if STYLE is not specified, the default style is used for all the layers of the group
- if STYLE is specified it should be a comma separated list to specify styles for any single layer of the group (empty values can be given to use default style for one or more layers)
- the RULE parameter is used similarly to STYLE to specify rules for some or all the styles
- the layer Title (or Name if title is missing) is drawn as a label on top of each layer
- forceTitles legend option can be used to force layer titles off or on