Add legend to layers with GetLegendGraphic if possible

[umbe1987]

It would be very nice if a WMS has the GetLegendGraphic capability to add the legend to the layer.

DOCUMENTATION

• http://mapserver.org/ogc/wms_server.html#getlegendgraphic-request
• https://enterprise.arcgis.com/en/server/latest/publish-services/windows/wms-services.htm
• http://docs.geoserver.org/stable/en/user/services/wms/get_legend_graphic/index.html

EXAMPLE

• https://servizigis.regione.emilia-romagna.it/wms/dbtr?service=wms&request=GetLegendGraphic&version=1.3.0&layer=LAB_Localita_abitata_poligonale&FORMAT=image/png&WIDTH=20&HEIGHT=20