if darkage is also installed,

don't register large homedecor lattice lamp or the recipes to
create it or to split it into 8 small lamps. instead, add an
alias to darkage:lamp and a recipe to split that.

homedecor/crafts.lua

@@ -1207,6 +1207,14 @@ minetest.register_craft({
 
 -- wood-lattice lamps
 
+if minetest.get_modpath("darkage") then
+	minetest.register_craft( {
+		output = "homedecor:lattice_lantern_small 8",
+		recipe = {
+			{ "darkage:lamp" },
+		},
+	})
+else
 	minetest.register_craft( {
 			output = "homedecor:lattice_lantern_large 2",
 			recipe = {
@@ -1222,6 +1230,7 @@ minetest.register_craft( {
 			{ "homedecor:lattice_lantern_large" },
 		},
 	})
+end
 
 -- glowlights
 

homedecor/depends.txt

@@ -14,3 +14,4 @@ flowers?
 3d_armor?
 skinsdb?
 mesecons?
+darkage?

homedecor/lighting.lua

@@ -360,6 +360,9 @@ homedecor.register("ceiling_lantern", {
 	walkable = false
 })
 
+if minetest.get_modpath("darkage") then
+	minetest.register_alias("homedecor:lattice_lantern_large", "darkage:lamp")
+else
 	homedecor.register("lattice_lantern_large", {
 		description = S("Lattice lantern (large)"),
 		tiles = { 'homedecor_lattice_lantern_large.png' },
@@ -367,6 +370,7 @@ homedecor.register("lattice_lantern_large", {
 		light_source = default.LIGHT_MAX,
 		sounds = default.node_sound_glass_defaults(),
 	})
+end
 
 homedecor.register("lattice_lantern_small", {
 	description = S("Lattice lantern (small)"),