Various overlay operations have been added to the expression engine. This covers the functionality of the refFunctions plugin.
The following new expression functions are implemented :
overlay_intersects(layer[,expression][,filter][,limit][,cache])
overlay_contains(layer[,expression][,filter][,limit][,cache])
overlay_crosses(layer[,expression][,filter][,limit][,cache])
overlay_equals(layer[,expression][,filter][,limit][,cache])
overlay_touches(layer[,expression][,filter][,limit][,cache])
overlay_disjoint(layer[,expression][,filter][,limit][,cache])
overlay_within(layer[,expression][,filter][,limit][,cache])
overlay_nearest(layer[,expression][,filter][,limit][,max_distance][,cache])
in all instances, the spatial operator is evaluated against the other layer. If an expression is provided, it returns an array of results. If no expression is provided, it returns a boolean indicating whether or not there is a match for at least one feature. Features can optionally be filtered by an expression, and optionally be limited to a certain count.
The overlay_nearest
function has an additional max_distance filter.
This feature was developed by Olivier Dalang, OPENGIS.ch