Legend widget by extent

Discussion created by hc_gis on Mar 18, 2013
Latest reply on Mar 20, 2013 by hc_gis
The current legend widget works in function of the map scale by showing the layers visible in every scale
But the frequent question posed by many of our customers is when there is no layer showed in the current extent , why showing these layers in the legend?
The first idea is in every  onExtentChange event we do a spatial query of visible layers in the current extent and push their symbols to the legend widget But i think this will affect the map performance.
Is there a plan to implement a legend widget by extent?
Best Regards