Add simple item fluid storage API

api.lua

@@ -151,6 +151,79 @@ industrialtest.api.afterToolUse=function(itemstack)
 	meta:set_int("industrialtest.uses",uses)
 	itemstack:set_wear(65535-uses/def.tool_capabilities.uses*65535)
 end
+
+-- \brief Check if itemstack contains fluid storage
+-- \param itemstack ItemStack
+-- \returns bool
+industrialtest.api.itemHasFluidStorage=function(itemstack)
+	local values={"industrialtest.fluidAmount","industrialtest.fluidCapacity"}
+	local meta=itemstack:get_meta()
+	for _,value in ipairs(values) do
+		if not meta:contains(value) then
+			return false
+		end
+	end
+	return true
+end
+
+-- \brief Updates itemstack description and wear depending on contained fluid
+-- \param itemstack ItemStack
+-- \returns nil
+industrialtest.api.updateItemFluidText=function(itemstack)
+	local meta=itemstack:get_meta()
+	local def=itemstack:get_definition()
+	meta:set_string("description",S("@1\n@2 / @3",def.description,meta:get_int("industrialtest.fluidAmount"),meta:get_int("industrialtest.fluidCapacity")))
+	itemstack:set_wear(65535-meta:get_int("industrialtest.fluidAmount")/meta:get_int("industrialtest.fluidCapacity")*65534)
+end
+
+-- \brief Prepares itemstack containing fluid storage
+-- \param itemstack ItemStack
+-- \returns bool
+industrialtest.api.prepareFluidStorageItem=function(itemstack)
+	local meta=itemstack:get_meta()
+	local def=itemstack:get_definition()
+	if industrialtest.api.itemHasFluidStorage(itemstack) or not def.groups or not def.groups._industrialtest_fluidStorage or not def._industrialtest_fluidCapacity then
+		return false
+	end
+	meta:set_int("industrialtest.fluidAmount",100)
+	meta:set_int("industrialtest.fluidCapacity",def._industrialtest_fluidCapacity)
+	industrialtest.api.updateItemFluidText(itemstack)
+	return true
+end
+
+-- \brief Adds fluid amount to item fluid storage
+-- \param itemstack ItemStack
+-- \param amount number
+-- \returns number
+industrialtest.api.addFluidToItem=function(itemstack,amount)
+	local meta=itemstack:get_meta()
+	if not industrialtest.api.itemHasFluidStorage(itemstack) then
+		return 0
+	end
+	local fluidAmount=meta:get_int("industrialtest.fluidAmount")
+	local fluidCapacity=meta:get_int("industrialtest.fluidCapacity")
+	local prevFluidAmount=fluidAmount
+	fluidAmount=industrialtest.internal.clamp(fluidAmount+amount,0,fluidCapacity)
+	meta:set_int("industrialtest.fluidAmount",fluidAmount)
+	industrialtest.api.updateItemFluidText(itemstack)
+	return fluidAmount-prevFluidAmount
+end
+
+-- \brief Adds fluid to destination itemstack while subtracting it from source metadata
+-- \param srcMeta MetaDataRef
+-- \param itemstack ItemStack
+-- \param amount number
+-- \returns number
+industrialtest.api.transferFluidToItem=function(srcMeta,itemstack,amount)
+	local flow=math.min(srcMeta:get_int("industrialtest.fluidAmount"),amount)
+	if flow==0 then
+		return 0
+	end
+	local actualFlow=industrialtest.api.addFluidToItem(itemstack,flow)
+	srcMeta:set_int("industrialtest.fluidAmount",srcMeta:get_int("industrialtest.fluidAmount")-actualFlow)
+	return actualFlow
+end
+
 -- \brief Checks if power storage is fully charged
 -- \param meta MetaDataRef which should be checked
 -- \returns true if power storage is fully charged, false otherwise
@@ -198,6 +271,7 @@ end
 -- \brief Adds power to destination itemstack while subtracting it from source metadata
 -- \param srcMeta MetaDataRef from which take power
 -- \param itemstack ItemStack to which add power
+-- \param amount number
 -- \returns How much of power was actually transferred
 industrialtest.api.transferPowerToItem=function(srcMeta,itemstack,amount)
 	local currentFlow=math.min(srcMeta:get_int("industrialtest.powerAmount"),amount)