Refactor Canning Machine

api/fluid.lua

@@ -45,6 +45,36 @@ function industrialtest.api.itemHasFluidStorage(itemstack)
 	return true
 end
 
+-- \brief Check if fluid storage in meta is full
+-- \param meta MetaDataRef
+-- \returns bool
+function industrialtest.api.isFluidStorageFull(meta)
+	return meta:get_int("industrialtest.fluidAmount")>=meta:get_int("industrialtest.fluidCapacity")
+end
+
+-- \brief Check if item fluid storage is full
+-- \param itemstack ItemStack
+-- \returns bool
+function industrialtest.api.isItemFluidStorageFull(itemstack)
+	local meta=itemstack:get_meta()
+	return industrialtest.api.isFluidStorageFull(meta)
+end
+
+-- \brief Check if fluid storage in meta is empty
+-- \param meta MetaDataRef
+-- \returns bool
+function industrialtest.api.isFluidStorageEmpty(meta)
+	return meta:get_int("industrialtest.fluidAmount")==0
+end
+
+-- \brief Check if item fluid storage is empty
+-- \param itemstack ItemStack
+-- \returns bool
+function industrialtest.api.isItemFluidStorageEmpty(itemstack)
+	local meta=itemstack:get_meta()
+	return industrialtest.api.isFluidStorageEmpty(meta)
+end
+
 -- \brief Updates itemstack description and wear depending on contained fluid
 -- \param itemstack ItemStack
 -- \returns nil

api/network.lua

@@ -76,17 +76,16 @@ function industrialtest.api.powerFlow(pos,sides,flowOverride)
 					transferred=true
 				end
 				local def=minetest.registered_nodes[minetest.get_node(endpoint.position).name]
-				if def then
-					local updateFormspec=def._industrialtest_updateFormspec
-					if updateFormspec then
-						updateFormspec(endpoint.position)
-					end
-					local onPowerFlow=def._industrialtest_onPowerFlow
-					if onPowerFlow and transferredPower>0 then
-						onPowerFlow(endpoint.position,industrialtest.api.getOppositeSide(endpoint.side),transferredPower)
+				if def and def._industrialtest_self then
+					def._industrialtest_self:updateFormspec(endpoint.position)
+					if def._industrialtest_self.onPowerFlow and transferredPower>0 then
+						def._industrialtest_self:onPowerFlow(endpoint.position,industrialtest.api.getOppositeSide(endpoint.side),transferredPower)
 					end
+					def._industrialtest_self:triggerIfNeeded(endpoint.position)
+				else
+					-- Support for bare definitions that don't use industrialtest pseudo-OOP
+					minetest.get_node_timer(endpoint.position):start(industrialtest.updateDelay)
 				end
-				minetest.get_node_timer(endpoint.position):start(industrialtest.updateDelay)
 				if not industrialtest.api.isFullyCharged(endpointMeta) then
 					roomAvailable=true
 				end

machines/activated_electric_machine.lua

@@ -22,6 +22,8 @@ function industrialtest.ActivatedElectricMachine.onTimer(self,pos,elapsed)
 	return result or result2
 end
 
+industrialtest.ActivatedElectricMachine.canUpdate=industrialtest.ActivatedMachine.canUpdate
+
 industrialtest.ActivatedElectricMachine.register=industrialtest.ActivatedMachine.register
 
 industrialtest.ActivatedElectricMachine.createDefinitionTable=industrialtest.ActivatedMachine.createDefinitionTable

machines/activated_machine.lua

@@ -16,6 +16,10 @@
 
 industrialtest.ActivatedMachine=table.copy(industrialtest.Machine)
 
+function industrialtest.ActivatedMachine.canUpdate(self,pos)
+	return self:shouldActivate(pos)
+end
+
 function industrialtest.ActivatedMachine.onTimer(self,pos,elapsed)
 	local result=industrialtest.Machine.onTimer(self,pos,elapsed)
 
@@ -81,14 +85,6 @@ function industrialtest.ActivatedMachine.activeOnTimer(self,pos,elapsed)
 	local shouldRerunTimer=false
 	local shouldUpdateFormspec=false
 
-	if self.activeUpdate then
-		shouldRerunTimer,shouldUpdateFormspec=self:activeUpdate(pos,elapsed,meta,inv)
-	end
-
-	if shouldUpdateFormspec then
-		self:updateFormspec(pos)
-	end
-
 	if self:shouldDeactivate(pos) then
 		minetest.swap_node(pos,{
 			name=self.name,
@@ -99,5 +95,13 @@ function industrialtest.ActivatedMachine.activeOnTimer(self,pos,elapsed)
 		return false
 	end
 
+	if self.activeUpdate then
+		shouldRerunTimer,shouldUpdateFormspec=self:activeUpdate(pos,elapsed,meta,inv)
+	end
+
+	if shouldUpdateFormspec then
+		self:updateFormspec(pos)
+	end
+
 	return shouldRerunTimer
 end

machines/canning_machine.lua

@@ -15,15 +15,66 @@
 -- along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 local S=minetest.get_translator("industrialtest")
-local canningMachine={}
+industrialtest.CanningMachine=table.copy(industrialtest.ActivatedElectricMachine)
+industrialtest.internal.unpackTableInto(industrialtest.CanningMachine,{
+	name="industrialtest:canning_machine",
+	description=S("Canning Machine"),
+	tiles={
+		"industrialtest_machine_block.png",
+		"industrialtest_machine_block.png",
+		"industrialtest_machine_block.png",
+		"industrialtest_machine_block.png",
+		"industrialtest_machine_block.png",
+		"industrialtest_machine_block.png^industrialtest_canning_machine_front.png",
+		"industrialtest_machine_block.png"
+	},
+	sounds="metal",
+	facedir=true,
+	storageLists={
+		"src",
+		"dst",
+		"leftover",
+		"upgrades",
+		"powerStorage"
+	},
+	powerLists={"powerStorage"},
+	active={
+		tiles={
+			"industrialtest_machine_block.png",
+			"industrialtest_machine_block.png",
+			"industrialtest_machine_block.png",
+			"industrialtest_machine_block.png",
+			"industrialtest_machine_block.png",
+			"industrialtest_machine_block.png^industrialtest_canning_machine_front_active.png",
+			"industrialtest_machine_block.png"
+		}
+	},
+	capacity=industrialtest.api.lvPowerFlow*2,
+	flow=industrialtest.api.lvPowerFlow,
+	ioConfig="iiiiii",
+	requiresWrench=true,
+	hasPowerInput=true,
+	_opPower=200,
+	_canningTime=5
+})
 
-canningMachine.opPower=200
-canningMachine.canningTime=5
+function industrialtest.CanningMachine.onConstruct(self,pos)
+	local meta=minetest.get_meta(pos)
+	local inv=meta:get_inventory()
+	inv:set_size("src",1)
+	inv:set_size("dst",1)
+	inv:set_size("leftover",1)
+	inv:set_size("powerStorage",1)
+	inv:set_size("upgrades",4)
+	meta:set_float("srcTime",0)
+	industrialtest.ActivatedElectricMachine.onConstruct(self,pos)
+end
 
-canningMachine.getFormspec=function(pos)
+function industrialtest.CanningMachine.getFormspec(self,pos)
+	local parentFormspec=industrialtest.ActivatedElectricMachine.getFormspec(self,pos)
 	local meta=minetest.get_meta(pos)
 	local powerPercent=meta:get_int("industrialtest.powerAmount")/meta:get_int("industrialtest.powerCapacity")*100
-	local srcPercent=meta:get_float("srcTime")/canningMachine.canningTime*100
+	local srcPercent=meta:get_float("srcTime")/self._canningTime*100
 	local formspec={
 		"list[context;src;3.4,1.8;1,1]",
 		industrialtest.internal.getItemSlotBg(3.4,1.8,1,1),
@@ -42,44 +93,10 @@ canningMachine.getFormspec=function(pos)
 		"listring[context;src]",
 		"listring[context;dst]"
 	}
-	return table.concat(formspec,"")
+	return parentFormspec..table.concat(formspec,"")
 end
 
-canningMachine.onConstruct=function(pos,meta,inv)
-	inv:set_size("src",1)
-	inv:set_size("dst",1)
-	inv:set_size("leftover",1)
-	inv:set_size("powerStorage",1)
-	inv:set_size("upgrades",4)
-	meta:set_float("srcTime",0)
-end
-
-canningMachine.onTimer=function(pos,elapsed,meta,inv)
-	local shouldRerunTimer=false
-	local shouldUpdateFormspec=false
-	local fuelSlot=inv:get_stack("src",1)
-	local targetSlot=inv:get_stack("dst",1)
-	local leftoverSlot=inv:get_stack("leftover",1)
-	local powerStorageSlot=inv:get_stack("powerStorage",1)
-	local targetMeta=targetSlot:get_meta()
-
-	shouldRerunTimer,shouldUpdateFormspec=industrialtest.internal.chargeFromPowerStorageItem(meta,inv)
-
-	local def=fuelSlot:get_definition()
-	if not fuelSlot:is_empty() and not targetSlot:is_empty() and meta:get_int("industrialtest.powerAmount")>=canningMachine.opPower and (not def._industrialtest_emptyVariant or leftoverSlot:item_fits(ItemStack(def._industrialtest_emptyVariant))) and
-		(not industrialtest.api.itemHasFluidStorage(fuelSlot) or fuelSlot:get_meta():get_int("industrialtest.fluidAmount")>0) and targetMeta:get_int("industrialtest.fluidAmount")<targetMeta:get_int("industrialtest.fluidCapacity") then
-		minetest.swap_node(pos,{
-			name="industrialtest:canning_machine_active",
-			param2=minetest.get_node(pos).param2
-		})
-		minetest.get_node_timer(pos):start(industrialtest.updateDelay)
-		return false,shouldUpdateFormspec
-	end
-	
-	return shouldRerunTimer,true
-end
-
-canningMachine.allowMetadataInventoryMove=function(pos,fromList,fromIndex,toList,count)
+function industrialtest.CanningMachine.allowMetadataInventoryMove(self,pos,fromList,fromIndex,toList,count)
 	if toList=="src" then
 		local inv=minetest.get_meta(pos):get_inventory()
 		local itemstack=inv:get_stack(fromList,fromIndex)
@@ -92,10 +109,10 @@ canningMachine.allowMetadataInventoryMove=function(pos,fromList,fromIndex,toList
 		local def=itemstack:get_definition()
 		return (def.groups and def.groups._industrialtest_fueled) and count or 0
 	end
-	return count
+	return math.min(count,industrialtest.ActivatedElectricMachine.allowMetadataInventoryMove(self,pos,fromList,fromIndex,toList,count))
 end
 
-canningMachine.allowMetadataInventoryPut=function(pos,listname,index,stack)
+function industrialtest.CanningMachine.allowMetadataInventoryPut(self,pos,listname,index,stack)
 	if listname=="src" then
 		local def=stack:get_definition()
 		return (def.groups and def.groups._industrialtest_fuel) and stack:get_count() or 0
@@ -104,10 +121,10 @@ canningMachine.allowMetadataInventoryPut=function(pos,listname,index,stack)
 		local def=stack:get_definition()
 		return (def.groups and def.groups._industrialtest_fueled) and stack:get_count() or 0
 	end
-	return stack:get_count()
+	return math.min(stack:get_count(),industrialtest.ActivatedElectricMachine.allowMetadataInventoryPut(self,pos,listname,index,stack))
 end
 
-canningMachine.allowMetadataInventoryTake=function(pos,listname,index,stack)
+function industrialtest.CanningMachine.allowMetadataInventoryTake(self,pos,listname,index,stack)
 	local meta=minetest.get_meta(pos)
 	local inv=meta:get_inventory()
 	local fuelSlot=inv:get_stack("src",1)
@@ -116,14 +133,11 @@ canningMachine.allowMetadataInventoryTake=function(pos,listname,index,stack)
 		meta:set_float("srcTime",0)
 		minetest.get_node_timer(pos):start(industrialtest.updateDelay)
 	end
-	return stack:get_count()
+	return industrialtest.ActivatedElectricMachine.allowMetadataInventoryTake(self,pos,listname,index,stack)
 end
 
-canningMachine.onMetadataInventoryPut=function(pos)
-	minetest.get_node_timer(pos):start(industrialtest.updateDelay)
-end
-
-canningMachine.onMetadataInventoryMove=function(pos,fromList,fromIndex,toList,toIndex,count)
+function industrialtest.CanningMachine.onMetadataInventoryMove(self,pos,fromList,fromIndex,toList,toIndex,count)
+	industrialtest.ActivatedElectricMachine.onMetadataInventoryMove(self,pos,fromList,fromIndex,toList,toIndex,count)
 	local meta=minetest.get_meta(pos)
 	local inv=meta:get_inventory()
 	local fuelSlot=inv:get_stack("src",1)
@@ -134,41 +148,62 @@ canningMachine.onMetadataInventoryMove=function(pos,fromList,fromIndex,toList,to
 	end
 end
 
-canningMachine.activeOnTimer=function(pos,elapsed,meta,inv)
+function industrialtest.CanningMachine.onMetadataInventoryPut(self,pos)
+	minetest.get_node_timer(pos):start(industrialtest.updateDelay)
+	industrialtest.ActivatedElectricMachine.onMetadataInventoryPut(self,pos,listname,index,stack)
+end
+
+function industrialtest.CanningMachine.shouldActivate(self,pos)
+	local meta=minetest.get_meta(pos)
+	local inv=meta:get_inventory()
+	local fuelSlot=inv:get_stack("src",1)
+	local targetSlot=inv:get_stack("dst",1)
+	local leftoverSlot=inv:get_stack("leftover",1)
+	local powerStorageSlot=inv:get_stack("powerStorage",1)
+	local targetMeta=targetSlot:get_meta()
+	local def=fuelSlot:get_definition()
+
+	return not fuelSlot:is_empty() and not targetSlot:is_empty() and meta:get_int("industrialtest.powerAmount")>=self._opPower and (not def._industrialtest_emptyVariant or leftoverSlot:item_fits(ItemStack(def._industrialtest_emptyVariant))) and
+		(not industrialtest.api.itemHasFluidStorage(fuelSlot) or fuelSlot:get_meta():get_int("industrialtest.fluidAmount")>0) and targetMeta:get_int("industrialtest.fluidAmount")<targetMeta:get_int("industrialtest.fluidCapacity")
+end
+
+function industrialtest.CanningMachine.shouldDeactivate(self,pos)
+	local meta=minetest.get_meta(pos)
+	local inv=meta:get_inventory()
+	local fuelSlot=inv:get_stack("src",1)
+	local fuelDef=fuelSlot:get_definition()
+	local targetSlot=inv:get_stack("dst",1)
+	local targetMeta=targetSlot:get_meta()
+	local leftoverSlot=inv:get_stack("leftover",1)
+
+	return fuelSlot:is_empty() or targetSlot:is_empty() or meta:get_int("industrialtest.powerAmount")<self._opPower or
+		(industrialtest.api.itemHasFluidStorage(fuelSlot) and industrialtest.api.isItemFluidStorageEmpty(fuelSlot)) or
+		industrialtest.api.isItemFluidStorageFull(targetSlot) or
+		targetMeta:get_int("industrialtest.fluidCapacity")-targetMeta:get_int("industrialtest.fluidAmount")<fuelDef._industrialtest_fuelAmount or
+		(fuelDef._industrialtest_emptyVariant and not leftoverSlot:item_fits(ItemStack(fuelDef._industrialtest_emptyVariant)))
+end
+
+function industrialtest.CanningMachine.afterDeactivation(self,pos)
+	minetest.debug("deactivated")
+	local meta=minetest.get_meta(pos)
+	local inv=meta:get_inventory()
+	local targetSlot=inv:get_stack("dst",1)
+	if meta:get_int("industrialtest.powerAmount")>=self._opPower or industrialtest.api.isItemFluidStorageFull(targetSlot) then
+		meta:set_float("srcTime",0)
+	end
+	self:updateFormspec(pos)
+end
+
+function industrialtest.CanningMachine.activeUpdate(self,pos,elapsed,meta,inv)
 	local shouldUpdateFormspec=false
 	local fuelSlot=inv:get_stack("src",1)
 	local targetSlot=inv:get_stack("dst",1)
 	local powerStorageSlot=inv:get_stack("powerStorage",1)
 
-	shouldRerunTimer,shouldUpdateFormspec=industrialtest.internal.chargeFromPowerStorageItem(meta,inv)
-
-	if fuelSlot:is_empty() or targetSlot:is_empty() or meta:get_int("industrialtest.powerAmount")<canningMachine.opPower then
-		if meta:get_int("industrialtest.powerAmount")>=canningMachine.opPower then
-			meta:set_float("srcTime",0)
-		end
-		minetest.swap_node(pos,{
-			name="industrialtest:canning_machine",
-			param2=minetest.get_node(pos).param2
-		})
-		minetest.get_node_timer(pos):start(industrialtest.updateDelay)
-		return false,true
-	end
-
 	local fuelMeta=fuelSlot:get_meta()
 	local targetMeta=targetSlot:get_meta()
-	if (industrialtest.api.itemHasFluidStorage(fuelSlot) and fuelMeta:get_int("industrialtest.fluidAmount")==0) or targetMeta:get_int("industrialtest.fluidAmount")==targetMeta:get_int("industrialtest.fluidCapacity") then
-		meta:set_float("srcTime",0)
-		minetest.swap_node(pos,{
-			name="industrialtest:canning_machine",
-			param2=minetest.get_node(pos).param2
-		})
-		minetest.get_node_timer(pos):start(industrialtest.updateDelay)
-		return false,true
-	end
-
-	local srcTime=meta:get_float("srcTime")
-	srcTime=srcTime+elapsed*industrialtest.api.getMachineSpeed(meta)
-	if srcTime>=canningMachine.canningTime then
+	local srcTime=meta:get_float("srcTime")+elapsed*industrialtest.api.getMachineSpeed(meta)
+	if srcTime>=self._canningTime then
 		if industrialtest.api.itemHasFluidStorage(fuelSlot) then
 			industrialtest.api.transferFluidToItem(fuelSlot,targetSlot,fuelMeta:get_int("industrialtest.fluidAmount"))
 			inv:set_stack("src",1,fuelSlot)
@@ -177,11 +212,6 @@ canningMachine.activeOnTimer=function(pos,elapsed,meta,inv)
 			local def=fuelSlot:get_definition()
 			local leftoverSlot=inv:get_stack("leftover",1)
 			if targetMeta:get_int("industrialtest.fluidCapacity")-targetMeta:get_int("industrialtest.fluidAmount")<def._industrialtest_fuelAmount or (def._industrialtest_emptyVariant and not leftoverSlot:item_fits(ItemStack(def._industrialtest_emptyVariant))) then
-				minetest.swap_node(pos,{
-					name="industrialtest:canning_machine",
-					param2=minetest.get_node(pos).param2
-				})
-				minetest.get_node_timer(pos):start(industrialtest.updateDelay)
 				return false,shouldUpdateFormspec
 			end
 			industrialtest.api.addFluidToItem(targetSlot,def._industrialtest_fuelAmount)
@@ -195,57 +225,13 @@ canningMachine.activeOnTimer=function(pos,elapsed,meta,inv)
 	else
 		meta:set_float("srcTime",srcTime)
 	end
-	industrialtest.api.addPower(meta,-canningMachine.opPower)
+	industrialtest.api.addPower(meta,-self._opPower)
 
 	return true,true
 end
 
-industrialtest.internal.registerMachine({
-	name="canning_machine",
-	displayName=S("Canning Machine"),
-	capacity=industrialtest.api.lvPowerFlow*2,
-	getFormspec=canningMachine.getFormspec,
-	flow=industrialtest.api.lvPowerFlow,
-	ioConfig="iiiiii",
-	requiresWrench=true,
-	registerActiveVariant=true,
-	sounds="metal",
-	powerSlots={"powerStorage"},
-	storageSlots={"src","dst","powerStorage","upgrades"},
-	groups={
-		_industrialtest_hasPowerInput=1
-	},
-	customKeys={
-		tiles={
-			"industrialtest_machine_block.png",
-			"industrialtest_machine_block.png",
-			"industrialtest_machine_block.png",
-			"industrialtest_machine_block.png",
-			"industrialtest_machine_block.png",
-			"industrialtest_machine_block.png^industrialtest_canning_machine_front.png"
-		},
-		paramtype2="facedir",
-		legacy_facedir_simple=true
-	},
-	activeCustomKeys={
-		tiles={
-			"industrialtest_machine_block.png",
-			"industrialtest_machine_block.png",
-			"industrialtest_machine_block.png",
-			"industrialtest_machine_block.png",
-			"industrialtest_machine_block.png",
-			"industrialtest_machine_block.png^industrialtest_canning_machine_front_active.png"
-		}
-	},
-	onConstruct=canningMachine.onConstruct,
-	onTimer=canningMachine.onTimer,
-	allowMetadataInventoryMove=canningMachine.allowMetadataInventoryMove,
-	allowMetadataInventoryPut=canningMachine.allowMetadataInventoryPut,
-	allowMetadataInventoryTake=canningMachine.allowMetadataInventoryTake,
-	onMetadataInventoryPut=canningMachine.onMetadataInventoryPut,
-	onMetadataInventoryMove=canningMachine.onMetadataInventoryMove,
-	activeOnTimer=canningMachine.activeOnTimer
-})
+industrialtest.CanningMachine:register()
+
 minetest.register_craft({
 	type="shaped",
 	output="industrialtest:canning_machine",

machines/electric_machine.lua

@@ -41,9 +41,9 @@ function industrialtest.ElectricMachine.onConstruct(self,pos)
 				end
 			end
 		end
-		if self.hasPowerOutput then
-			meta:set_string("industrialtest.network",minetest.serialize(industrialtest.api.createNetworkMap(pos)))
-		end
+	end
+	if self.hasPowerOutput then
+		meta:set_string("industrialtest.network",minetest.serialize(industrialtest.api.createNetworkMap(pos)))
 	end
 
 	industrialtest.Machine.onConstruct(self,pos)
@@ -82,7 +82,7 @@ function industrialtest.ElectricMachine.onTimer(self,pos,elapsed)
 	return result or result2
 end
 
-function industrialtest.Machine.allowMetadataInventoryMove(self,pos,fromList,fromIndex,toList,toIndex,count)
+function industrialtest.ElectricMachine.allowMetadataInventoryMove(self,pos,fromList,fromIndex,toList,toIndex,count)
 	local found=false
 	if self.powerLists then
 		for _,value in ipairs(self.powerLists) do
@@ -99,7 +99,7 @@ function industrialtest.Machine.allowMetadataInventoryMove(self,pos,fromList,fro
 	return industrialtest.Machine.allowMetadataInventoryMove(self,pos,fromList,fromIndex,toList,toIndex,count)
 end
 
-function industrialtest.Machine.allowMetadataInventoryPut(self,pos,listname,index,stack,player)
+function industrialtest.ElectricMachine.allowMetadataInventoryPut(self,pos,listname,index,stack,player)
 	local found=false
 	if self.powerLists then
 		for _,value in ipairs(self.powerLists) do
@@ -116,6 +116,20 @@ function industrialtest.Machine.allowMetadataInventoryPut(self,pos,listname,inde
 	return industrialtest.Machine.allowMetadataInventoryPut(self,pos,listname,index,stack,player)
 end
 
+function industrialtest.ElectricMachine.requestPower(self,pos)
+	if not self.hasPowerOutput then
+		return
+	end
+	local meta=minetest.get_meta(pos)
+	if meta:get_int("industrialtest.powerAmount")<=0 then
+		return
+	end
+	local spaceAvailable,flowTransferred=industrialtest.api.powerFlow(pos)
+	if (spaceAvailable and meta:get_int("industrialtest.powerAmount")>0) or self:canUpdate(pos) then
+		minetest.get_node_timer(pos):start(industrialtest.updateDelay)
+	end
+end
+
 function industrialtest.ElectricMachine.powerExchange(self,pos)
 	local meta=minetest.get_meta(pos)
 	local shouldRerunTimer=false
@@ -124,7 +138,13 @@ function industrialtest.ElectricMachine.powerExchange(self,pos)
 		local networks=industrialtest.api.isAttachedToNetwork(meta)
 		if networks then
 			for _,network in ipairs(networks) do
-				minetest.get_node_timer(network):start(industrialtest.updateDelay)
+				local def=minetest.registered_nodes[minetest.get_node(network).name]
+				if def and def._industrialtest_self then
+					def._industrialtest_self:requestPower(network)
+				else
+					-- Support for bare definitions that don't use industrialtest pseudo-OOP
+					minetest.get_node_timer(network):start(industrialtest.updateDelay)
+				end
 			end
 		end
 		shouldRerunTimer=shouldRerunTimer or not industrialtest.api.isFullyCharged(meta)

machines/machine.lua

@@ -60,6 +60,18 @@ function industrialtest.Machine.updateFormspec(self,pos)
 	meta:set_string("formspec",self:getFormspec(pos))
 end
 
+function industrialtest.Machine.canUpdate(self,pos)
+	return false
+end
+
+function industrialtest.Machine.triggerIfNeeded(self,pos)
+	local timer=minetest.get_node_timer(pos)
+	if not timer:is_started() and self:canUpdate(pos) then
+		minetest.debug("updating "..minetest.serialize(pos))
+		timer:start(industrialtest.updateDelay)
+	end
+end
+
 function industrialtest.Machine.onTimer(self,pos,elapsed)
 	local meta=minetest.get_meta(pos)
 	local inv=meta:get_inventory()