From b2a7f5430ace197e5eadb81e6b42ea133d4113a6 Mon Sep 17 00:00:00 2001
From: Jean-Patrick Guerrero <jeanpatrick.guerrero@gmail.com>
Date: Thu, 13 Dec 2018 17:39:47 +0100
Subject: [PATCH 1/8] Add a /craft command to show recipe of pointed node

---
 .luacheckrc |   1 +
 init.lua    | 118 +++++++++++++++++++++++++++++++++++++---------------
 2 files changed, 85 insertions(+), 34 deletions(-)

diff --git a/.luacheckrc b/.luacheckrc
index dc9f4aa..6ade552 100644
--- a/.luacheckrc
+++ b/.luacheckrc
@@ -6,4 +6,5 @@ read_globals = {
 	"default",
 	"sfinv",
 	"sfinv_buttons",
+	"vector",
 }
diff --git a/init.lua b/init.lua
index 934441d..bc46b25 100644
--- a/init.lua
+++ b/init.lua
@@ -16,6 +16,7 @@ craftguide.intllib = S
 -- Lua 5.3 removed `table.maxn`, use this alternative in case of breakage:
 -- https://github.com/kilbith/xdecor/blob/master/handlers/helpers.lua#L1
 local remove, maxn, sort = table.remove, table.maxn, table.sort
+local vector_add, vector_mul = vector.add, vector.multiply
 local min, max, floor, ceil = math.min, math.max, math.floor, math.ceil
 
 local DEFAULT_SIZE = 10
@@ -380,6 +381,10 @@ function craftguide:get_init_items()
 	datas.init_items = items_list
 end
 
+minetest.register_on_mods_loaded(function()
+	craftguide:get_init_items()
+end)
+
 function craftguide:get_filter_items(data, player)
 	local filter = data.filter
 	if datas.searches[filter] then
@@ -454,6 +459,16 @@ function craftguide:get_item_usages(item)
 	return usages
 end
 
+local show_fs = function(player, player_name, is_fuel)
+	if sfinv_only then
+		local context = sfinv.get_or_create_context(player)
+		context.fuel = is_fuel
+		sfinv.set_player_inventory_formspec(player, context)
+	else
+		craftguide:get_formspec(player_name, is_fuel)
+	end
+end
+
 local function get_fields(player, ...)
 	local args, formname, fields = {...}
 	if sfinv_only then
@@ -466,16 +481,6 @@ local function get_fields(player, ...)
 	local player_name = player:get_player_name()
 	local data = datas[player_name]
 
-	local show_fs = function(is_fuel)
-		if sfinv_only then
-			local context = sfinv.get_or_create_context(player)
-			context.fuel = is_fuel
-			sfinv.set_player_inventory_formspec(player, context)
-		else
-			craftguide:get_formspec(player_name, is_fuel)
-		end
-	end
-
 	if fields.clear then
 		data.show_usage = nil
 		data.filter     = ""
@@ -484,7 +489,7 @@ local function get_fields(player, ...)
 		data.rnum       = 1
 
 		data.items = progressive_mode and data.init_filter_items or datas.init_items
-		show_fs()
+		show_fs(player, player_name)
 
 	elseif fields.alternate then
 		local num
@@ -495,14 +500,16 @@ local function get_fields(player, ...)
 		end
 
 		data.rnum = num and data.rnum + 1 or 1
-		show_fs()
+
+		show_fs(player, player_name)
 
 	elseif (fields.key_enter_field == "filter" or fields.search) and
 			fields.filter ~= "" then
 		data.filter = fields.filter:lower()
 		data.pagenum = 1
 		craftguide:get_filter_items(data, player)
-		show_fs()
+
+		show_fs(player, player_name)
 
 	elseif fields.prev or fields.next then
 		data.pagenum = data.pagenum - (fields.prev and 1 or -1)
@@ -513,13 +520,14 @@ local function get_fields(player, ...)
 			data.pagenum = data.pagemax
 		end
 
-		show_fs()
+		show_fs(player, player_name)
 
 	elseif (fields.size_inc and data.iX < MAX_LIMIT) or
 			(fields.size_dec and data.iX > MIN_LIMIT) then
 		data.pagenum = 1
 		data.iX = data.iX - (fields.size_dec and 1 or -1)
-		show_fs()
+
+		show_fs(player, player_name)
 
 	else for item in pairs(fields) do
 		if item:find(":") then
@@ -540,7 +548,7 @@ local function get_fields(player, ...)
 					data.rnum = 1
 				end
 
-				show_fs()
+				show_fs(player, player_name)
 			else
 				if progressive_mode then
 					local inv = player:get_inventory()
@@ -555,13 +563,20 @@ local function get_fields(player, ...)
 				data.rnum         = 1
 				data.show_usage   = nil
 
-				show_fs(is_fuel)
+				show_fs(player, player_name, is_fuel)
 			end
 		end
 	     end
 	end
 end
 
+local function init_datas(user, name)
+	datas[name] = {filter = "", pagenum = 1, iX = sfinv_only and 8 or DEFAULT_SIZE}
+	if progressive_mode then
+		craftguide:get_filter_items(datas[name], user)
+	end
+end
+
 if sfinv_only then
 	sfinv.register_page("craftguide:craftguide", {
 		title = "Craft Guide",
@@ -574,18 +589,11 @@ if sfinv_only then
 			)
 		end,
 		on_enter = function(self, player, context)
-			if not datas.init_items then
-				craftguide:get_init_items()
-			end
-
 			local player_name = player:get_player_name()
 			local data = datas[player_name]
 
 			if progressive_mode or not data then
-				datas[player_name] = {filter = "", pagenum = 1, iX = 8}
-				if progressive_mode then
-					craftguide:get_filter_items(datas[player_name], player)
-				end
+				init_datas(player, player_name)
 			end
 		end,
 		on_player_receive_fields = function(self, player, context, fields)
@@ -596,19 +604,11 @@ else
 	mt.register_on_player_receive_fields(get_fields)
 
 	function craftguide:on_use(itemstack, user)
-		if not datas.init_items then
-			self:get_init_items()
-		end
-
 		local player_name = user:get_player_name()
 		local data = datas[player_name]
 
 		if progressive_mode or not data then
-			datas[player_name] = {filter = "", pagenum = 1, iX = DEFAULT_SIZE}
-			if progressive_mode then
-				self:get_filter_items(datas[player_name], user)
-			end
-
+			init_datas(user, player_name)
 			self:get_formspec(player_name)
 		else
 			show_formspec(player_name, "craftguide", data.formspec)
@@ -687,6 +687,56 @@ if rawget(_G, "sfinv_buttons") then
 	})
 end
 
+if not progressive_mode then
+	minetest.register_chatcommand("craft", {
+		description = S("Show recipe(s) of the pointed node"),
+		func = function(name)
+			local player = minetest.get_player_by_name(name)
+			local ppos   = player:get_pos()
+			local dir    = player:get_look_dir()
+			local eye_h  = {x = ppos.x, y = ppos.y + 1.625, z = ppos.z}
+			local node_name
+
+			for i = 1, 10 do
+				local look_at = vector_add(eye_h, vector_mul(dir, i))
+				local node = minetest.get_node(look_at)
+
+				if node.name ~= "air" then
+					node_name = node.name
+					break
+				end
+			end
+
+			if not node_name then
+				return false, colorize("[craftguide] ") .. S("No node pointed")
+			elseif not datas[name] then
+				init_datas(player, name)
+			end
+
+			local data    = datas[name]
+			local is_fuel = get_fueltime(node_name) > 0
+			local recipes = get_recipes(node_name)
+
+			if not recipes and not is_fuel then
+				return false, colorize("[craftguide] ") ..
+					S("No recipe for this node:") .. " " ..
+					colorize(node_name)
+			end
+
+			data.show_usage   = nil
+			data.filter       = ""
+			data.item         = node_name
+			data.pagenum      = 1
+			data.rnum         = 1
+			data.recipes_item = recipes
+			data.items        = progressive_mode and data.init_filter_items or
+					    datas.init_items
+
+			return true, show_fs(player, name, is_fuel)
+		end,
+	})
+end
+
 --[[ Custom recipes (>3x3) test code
 
 mt.register_craftitem("craftguide:custom_recipe_test", {

From 53833af635434bf5ae307a951ad20bdf3eba5cbc Mon Sep 17 00:00:00 2001
From: Jean-Patrick Guerrero <jeanpatrick.guerrero@gmail.com>
Date: Sun, 16 Dec 2018 23:20:54 +0100
Subject: [PATCH 2/8] Add an API for custom recipes

---
 README.md |  29 +++++-
 init.lua  | 281 ++++++++++++++++++++++++++++++++++--------------------
 2 files changed, 205 insertions(+), 105 deletions(-)

diff --git a/README.md b/README.md
index 2896ced..0eb6c64 100644
--- a/README.md
+++ b/README.md
@@ -3,13 +3,36 @@
 #### `craftguide` is the most comprehensive crafting guide on Minetest. ####
 #### Consult the [Minetest Wiki](http://wiki.minetest.net/Crafting_guide) for more details. ####
 
-#### This crafting guide is usable with a blue book named *"Crafting Guide"* ####
+This crafting guide is a blue book named *"Crafting Guide"* or a wooden sign.
 
-#### This crafting guide features two modes : Standard and Progressive. ####
-The Progressive mode is a Terraria-like system that only shows recipes you can craft from items in inventory.
+This crafting guide features a **progressive mode**.
+The progressive mode is a Terraria-like system that only shows recipes you can craft from items in inventory.
 The progressive mode can be enabled with `craftguide_progressive_mode = true` in `minetest.conf`.
 
 `craftguide` is also integrated in `sfinv` (Minetest Game inventory) when you enable it with
 `craftguide_sfinv_only = true` in `minetest.conf`.
 
+Use the command `/craft` to show the recipe(s) of the pointed node.
+
+---
+
+`craftguide` has an API to register **custom recipes**. Demos:
+#### Registering a custom crafting type ####
+```Lua
+craftguide.register_craft_type("digging", {
+	description = S("Digging"),
+	icon  = "default_tool_steelpick.png",
+	width = 1,
+})
+```
+
+#### Registering a custom crafting recipe ####
+```Lua
+craftguide.register_craft({
+	type   = "digging",
+	output = "default:cobble",
+	items  = {"default:stone"},
+})
+```
+
 ![Preview2](https://i.imgur.com/bToFH38.png)
diff --git a/init.lua b/init.lua
index bc46b25..7c2b70b 100644
--- a/init.lua
+++ b/init.lua
@@ -1,4 +1,10 @@
-local craftguide, datas, mt = {}, {searches = {}}, minetest
+local craftguide = {
+	custom_crafts = {},
+	craft_types = {},
+}
+
+local mt = minetest
+local datas = {searches = {}}
 
 local progressive_mode = mt.settings:get_bool("craftguide_progressive_mode")
 local sfinv_only       = mt.settings:get_bool("craftguide_sfinv_only")
@@ -7,7 +13,7 @@ local get_recipe, get_recipes = mt.get_craft_recipe, mt.get_all_craft_recipes
 local get_result, show_formspec = mt.get_craft_result, mt.show_formspec
 local reg_items = mt.registered_items
 
-craftguide.path = minetest.get_modpath("craftguide")
+craftguide.path = mt.get_modpath("craftguide")
 
 -- Intllib
 local S = dofile(craftguide.path .. "/intllib.lua")
@@ -36,6 +42,106 @@ local group_stereotypes = {
 	mesecon_conductor_craftable = "mesecons:wire_00000000_off",
 }
 
+local function extract_groups(str)
+	if str:sub(1,6) ~= "group:" then return end
+	return str:sub(7):split(",")
+end
+
+function craftguide.register_craft_type(name, def)
+	if not craftguide.craft_types[name] then
+		craftguide.craft_types[name] = def
+	end
+end
+
+craftguide.register_craft_type("digging", {
+	description = S("Digging"),
+	icon  = "default_tool_steelpick.png",
+	width = 1,
+})
+
+function craftguide.register_craft(def)
+	craftguide.custom_crafts[#craftguide.custom_crafts + 1] = def
+end
+
+craftguide.register_craft({
+	type   = "digging",
+	output = "default:cobble",
+	items  = {"default:stone"},
+})
+
+local function colorize(str)
+	return mt.colorize("#FFFF00", str)
+end
+
+local function get_fueltime(item)
+	return get_result({method = "fuel", width = 1, items = {item}}).time
+end
+
+local function reset_datas(data)
+	data.show_usage = nil
+	data.filter     = ""
+	data.item       = nil
+	data.pagenum    = 1
+	data.rnum       = 1
+	data.fuel       = nil
+end
+
+local function in_table(T)
+	for i = 1, #T do
+		if T[i] then
+			return true
+		end
+	end
+end
+
+local function group_to_items(group)
+	local items_with_group, counter = {}, 0
+	for name, def in pairs(reg_items) do
+		if def.groups[group:sub(7)] then
+			counter = counter + 1
+			items_with_group[counter] = name
+		end
+	end
+
+	return items_with_group
+end
+
+local function item_in_inv(inv, item)
+	return inv:contains_item("main", item)
+end
+
+local show_fs = function(player, player_name)
+	if sfinv_only then
+		local context = sfinv.get_or_create_context(player)
+		sfinv.set_player_inventory_formspec(player, context)
+	else
+		craftguide:get_formspec(player_name)
+	end
+end
+
+local function init_datas(user, name)
+	datas[name] = {filter = "", pagenum = 1, iX = sfinv_only and 8 or DEFAULT_SIZE}
+	if progressive_mode then
+		craftguide:get_filter_items(datas[name], user)
+	end
+end
+
+local function add_custom_recipes(item, recipes)
+	for j = 1, #craftguide.custom_crafts do
+		local craft = craftguide.custom_crafts[j]
+		if craft.output:match("%S*") == item then
+			recipes[#recipes + 1] = {
+				width  = craftguide.craft_types[craft.type].width,
+				type   = craft.type,
+				items  = craft.items,
+				output = craft.output,
+			}
+		end
+	end
+
+	return recipes
+end
+
 function craftguide:group_to_item(item)
 	if item:sub(1,6) == "group:" then
 		local itemsub = item:sub(7)
@@ -55,19 +161,6 @@ function craftguide:group_to_item(item)
 	return item:sub(1,6) == "group:" and "" or item
 end
 
-local function extract_groups(str)
-	if str:sub(1,6) ~= "group:" then return end
-	return str:sub(7):split(",")
-end
-
-local function colorize(str)
-	return mt.colorize("#FFFF00", str)
-end
-
-local function get_fueltime(item)
-	return get_result({method = "fuel", width = 1, items = {item}}).time
-end
-
 function craftguide:get_tooltip(item, recipe_type, cooktime, groups)
 	local tooltip, item_desc = "tooltip[" .. item .. ";", ""
 	local fueltime = get_fueltime(item)
@@ -129,7 +222,7 @@ function craftguide:get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 	local rows = ceil(maxn(items) / width)
 	local rightest, s_btn_size = 0
 
-	if recipe_type == "normal" and (width > GRID_LIMIT or rows > GRID_LIMIT) then
+	if recipe_type ~= "fuel" and (width > GRID_LIMIT or rows > GRID_LIMIT) then
 		formspec = formspec ..
 			"label[" .. ((iX / 2) - 2) .. "," .. (iY + 2.2) .. ";" ..
 				S("Recipe is too big to be displayed (@1x@2)", width, rows) .. "]"
@@ -140,7 +233,7 @@ function craftguide:get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 				 (sfinv_only and 0 or 0.2)
 			local Y = ceil(i / width + (iY + 2) - min(2, rows))
 
-			if recipe_type == "normal" and (width > 3 or rows > 3) then
+			if recipe_type ~= "fuel" and (width > 3 or rows > 3) then
 				BUTTON_SIZE = width > 3 and 3 / width or 3 / rows
 				s_btn_size = BUTTON_SIZE
 				X = BUTTON_SIZE * (i % width) + xoffset - 2.65
@@ -166,15 +259,25 @@ function craftguide:get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 		BUTTON_SIZE = 1.1
 	end
 
-	if recipe_type == "cooking" or (recipe_type == "normal" and width == 0) then
-		local icon = recipe_type == "cooking" and "furnace" or "shapeless"
+	local custom_recipe = self.craft_types[recipe_type]
+	if recipe_type == "cooking" or (recipe_type == "normal" and width == 0) or
+			custom_recipe then
+		local icon   = recipe_type == "cooking" and "furnace" or "shapeless"
+		local coords = (rightest + 1.2) .. "," ..
+			       (iY + (sfinv_only and 2.2 or 1.7)) ..
+			       ";0.5,0.5;"
+
 		formspec = formspec ..
-			"image[" .. (rightest + 1.2) .. "," ..
-				(iY + (sfinv_only and 2.2 or 1.7)) ..
-				";0.5,0.5;craftguide_" .. icon .. ".png]"
+			"image[" .. coords ..
+				(custom_recipe and custom_recipe.icon or
+				 "craftguide_" .. icon .. ".png^[resize:16x16") .. "]" ..
+			"tooltip[" .. coords ..
+				(custom_recipe and custom_recipe.description or
+					recipe_type:gsub("^%l", string.upper)) .. "]"
 	end
 
-	local output = recipes[recipe_num].output:match("%S+")
+	local output   = recipes[recipe_num].output
+	local output_s = output:match("%S+")
 	local output_is_fuel = get_fueltime(output) > 0
 
 	local arrow_X  = rightest + (s_btn_size or BUTTON_SIZE)
@@ -188,9 +291,9 @@ function craftguide:get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 		"item_image_button[" .. output_X .. "," ..
 				(iY + (sfinv_only and 2.7 or 2.2)) .. ";" ..
 				BUTTON_SIZE .. "," .. BUTTON_SIZE .. ";" ..
-				output .. ";" .. output .. ";]" ..
+				output .. ";" .. output_s .. ";]" ..
 
-		self:get_tooltip(output)
+		self:get_tooltip(output_s)
 
 	if output_is_fuel then
 		formspec = formspec ..
@@ -206,7 +309,7 @@ function craftguide:get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 	return formspec
 end
 
-function craftguide:get_formspec(player_name, is_fuel)
+function craftguide:get_formspec(player_name)
 	local data = datas[player_name]
 	local iY = sfinv_only and 4 or data.iX - 5
 	local ipp = data.iX * iY
@@ -270,7 +373,7 @@ function craftguide:get_formspec(player_name, is_fuel)
 	end
 
 	if data.item and reg_items[data.item] then
-		if not data.recipes_item or (is_fuel and not get_recipe(data.item).items) then
+		if not data.recipes_item or (data.fuel and not get_recipe(data.item).items) then
 			local X = floor(xoffset) - (sfinv_only and 0 or 0.2)
 			formspec = formspec ..
 				"item_image_button[" .. X .. "," ..
@@ -308,30 +411,6 @@ function craftguide:get_formspec(player_name, is_fuel)
 	end
 end
 
-local function player_has_item(T)
-	for i = 1, #T do
-		if T[i] then
-			return true
-		end
-	end
-end
-
-local function group_to_items(group)
-	local items_with_group, counter = {}, 0
-	for name, def in pairs(reg_items) do
-		if def.groups[group:sub(7)] then
-			counter = counter + 1
-			items_with_group[counter] = name
-		end
-	end
-
-	return items_with_group
-end
-
-local function item_in_inv(inv, item)
-	return inv:contains_item("main", item)
-end
-
 function craftguide:recipe_in_inv(inv, item_name, recipes_f)
 	local recipes = recipes_f or get_recipes(item_name) or {}
 	local show_item_recipes = {}
@@ -360,20 +439,41 @@ function craftguide:recipe_in_inv(inv, item_name, recipes_f)
 		end
 	end
 
-	return recipes, player_has_item(show_item_recipes)
+	return recipes, in_table(show_item_recipes)
 end
 
 function craftguide:get_init_items()
-	local items_list, counter = {}, 0
+	local items_list, c = {}, 0
+	local function list(name)
+		c = c + 1
+		items_list[c] = name
+	end
+
 	for name, def in pairs(reg_items) do
 		local is_fuel = get_fueltime(name) > 0
 		if (not (def.groups.not_in_craft_guide == 1 or
 			 def.groups.not_in_creative_inventory == 1)) and
 		        (get_recipe(name).items or is_fuel) and
 			 def.description and def.description ~= "" then
+				list(name)
+		end
+	end
 
-			counter = counter + 1
-			items_list[counter] = name
+	for i = 1, #self.custom_crafts do
+		local craft  = self.custom_crafts[i]
+		local output = craft.output:match("%S*")
+		local listed
+
+		for j = 1, #items_list do
+			local listed_item = items_list[j]
+			if output == listed_item then
+				listed = true
+				break
+			end
+		end
+
+		if not listed then
+			list(output)
 		end
 	end
 
@@ -381,7 +481,7 @@ function craftguide:get_init_items()
 	datas.init_items = items_list
 end
 
-minetest.register_on_mods_loaded(function()
+mt.register_on_mods_loaded(function()
 	craftguide:get_init_items()
 end)
 
@@ -459,16 +559,6 @@ function craftguide:get_item_usages(item)
 	return usages
 end
 
-local show_fs = function(player, player_name, is_fuel)
-	if sfinv_only then
-		local context = sfinv.get_or_create_context(player)
-		context.fuel = is_fuel
-		sfinv.set_player_inventory_formspec(player, context)
-	else
-		craftguide:get_formspec(player_name, is_fuel)
-	end
-end
-
 local function get_fields(player, ...)
 	local args, formname, fields = {...}
 	if sfinv_only then
@@ -482,12 +572,7 @@ local function get_fields(player, ...)
 	local data = datas[player_name]
 
 	if fields.clear then
-		data.show_usage = nil
-		data.filter     = ""
-		data.item       = nil
-		data.pagenum    = 1
-		data.rnum       = 1
-
+		reset_datas(data)
 		data.items = progressive_mode and data.init_filter_items or datas.init_items
 		show_fs(player, player_name)
 
@@ -500,7 +585,6 @@ local function get_fields(player, ...)
 		end
 
 		data.rnum = num and data.rnum + 1 or 1
-
 		show_fs(player, player_name)
 
 	elseif (fields.key_enter_field == "filter" or fields.search) and
@@ -508,7 +592,6 @@ local function get_fields(player, ...)
 		data.filter = fields.filter:lower()
 		data.pagenum = 1
 		craftguide:get_filter_items(data, player)
-
 		show_fs(player, player_name)
 
 	elseif fields.prev or fields.next then
@@ -526,7 +609,6 @@ local function get_fields(player, ...)
 			(fields.size_dec and data.iX > MIN_LIMIT) then
 		data.pagenum = 1
 		data.iX = data.iX - (fields.size_dec and 1 or -1)
-
 		show_fs(player, player_name)
 
 	else for item in pairs(fields) do
@@ -538,8 +620,9 @@ local function get_fields(player, ...)
 			end
 
 			local is_fuel = get_fueltime(item) > 0
-			local recipes = get_recipes(item)
-			if not recipes and not is_fuel then return end
+			local recipes = get_recipes(item) or {}
+			recipes = add_custom_recipes(item, recipes)
+			if not next(recipes) and not is_fuel then return end
 
 			if not data.show_usage and item == data.item and not progressive_mode then
 				data.usages = craftguide:get_item_usages(item)
@@ -552,31 +635,24 @@ local function get_fields(player, ...)
 			else
 				if progressive_mode then
 					local inv = player:get_inventory()
-					local _, has_item = craftguide:recipe_in_inv(inv, item)
-
+					local recipes, has_item =
+						craftguide:recipe_in_inv(inv, item, recipes)
 					if not has_item then return end
-					recipes = craftguide:recipe_in_inv(inv, item, recipes)
 				end
 
-				data.item         = item
-				data.recipes_item = recipes
-				data.rnum         = 1
-				data.show_usage   = nil
+				data.item          = item
+				data.recipes_item  = recipes
+				data.rnum          = 1
+				data.show_usage    = nil
+				data.fuel          = is_fuel
 
-				show_fs(player, player_name, is_fuel)
+				show_fs(player, player_name)
 			end
 		end
 	     end
 	end
 end
 
-local function init_datas(user, name)
-	datas[name] = {filter = "", pagenum = 1, iX = sfinv_only and 8 or DEFAULT_SIZE}
-	if progressive_mode then
-		craftguide:get_filter_items(datas[name], user)
-	end
-end
-
 if sfinv_only then
 	sfinv.register_page("craftguide:craftguide", {
 		title = "Craft Guide",
@@ -585,7 +661,7 @@ if sfinv_only then
 			return sfinv.make_formspec(
 				player,
 				context,
-				craftguide:get_formspec(player_name, context.fuel)
+				craftguide:get_formspec(player_name)
 			)
 		end,
 		on_enter = function(self, player, context)
@@ -643,7 +719,7 @@ else
 			wall_side   = {-0.5, -0.3125, -0.4375, -0.4375, 0.3125, 0.4375}
 		},
 		on_construct = function(pos)
-			local meta = minetest.get_meta(pos)
+			local meta = mt.get_meta(pos)
 			meta:set_string("infotext", S("Crafting Guide Sign"))
 		end,
 		on_rightclick = function(pos, node, user, itemstack)
@@ -688,10 +764,10 @@ if rawget(_G, "sfinv_buttons") then
 end
 
 if not progressive_mode then
-	minetest.register_chatcommand("craft", {
+	mt.register_chatcommand("craft", {
 		description = S("Show recipe(s) of the pointed node"),
 		func = function(name)
-			local player = minetest.get_player_by_name(name)
+			local player = mt.get_player_by_name(name)
 			local ppos   = player:get_pos()
 			local dir    = player:get_look_dir()
 			local eye_h  = {x = ppos.x, y = ppos.y + 1.625, z = ppos.z}
@@ -699,7 +775,7 @@ if not progressive_mode then
 
 			for i = 1, 10 do
 				local look_at = vector_add(eye_h, vector_mul(dir, i))
-				local node = minetest.get_node(look_at)
+				local node = mt.get_node(look_at)
 
 				if node.name ~= "air" then
 					node_name = node.name
@@ -715,9 +791,10 @@ if not progressive_mode then
 
 			local data    = datas[name]
 			local is_fuel = get_fueltime(node_name) > 0
-			local recipes = get_recipes(node_name)
+			local recipes = get_recipes(node_name) or {}
+			recipes = add_custom_recipes(node_name, recipes)
 
-			if not recipes and not is_fuel then
+			if not next(recipes) and not is_fuel then
 				return false, colorize("[craftguide] ") ..
 					S("No recipe for this node:") .. " " ..
 					colorize(node_name)
@@ -729,10 +806,10 @@ if not progressive_mode then
 			data.pagenum      = 1
 			data.rnum         = 1
 			data.recipes_item = recipes
-			data.items        = progressive_mode and data.init_filter_items or
-					    datas.init_items
+			data.items        = datas.init_items
+			data.fuel         = is_fuel
 
-			return true, show_fs(player, name, is_fuel)
+			return true, show_fs(player, name)
 		end,
 	})
 end

From 610117de08f3a395e8521a031cd0d2af92243e88 Mon Sep 17 00:00:00 2001
From: Jean-Patrick Guerrero <jeanpatrick.guerrero@gmail.com>
Date: Mon, 17 Dec 2018 00:38:58 +0100
Subject: [PATCH 3/8] Make craftguide a global var

---
 init.lua | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/init.lua b/init.lua
index 7c2b70b..5e75ed1 100644
--- a/init.lua
+++ b/init.lua
@@ -1,4 +1,4 @@
-local craftguide = {
+craftguide = {
 	custom_crafts = {},
 	craft_types = {},
 }

From 9da500ce2c246623df7134d9b633d727d181805a Mon Sep 17 00:00:00 2001
From: Jean-Patrick Guerrero <jeanpatrick.guerrero@gmail.com>
Date: Mon, 17 Dec 2018 01:02:19 +0100
Subject: [PATCH 4/8] ... and make the other functions local

---
 init.lua | 216 +++++++++++++++++++++++++++----------------------------
 1 file changed, 108 insertions(+), 108 deletions(-)

diff --git a/init.lua b/init.lua
index 5e75ed1..cda282a 100644
--- a/init.lua
+++ b/init.lua
@@ -110,39 +110,7 @@ local function item_in_inv(inv, item)
 	return inv:contains_item("main", item)
 end
 
-local show_fs = function(player, player_name)
-	if sfinv_only then
-		local context = sfinv.get_or_create_context(player)
-		sfinv.set_player_inventory_formspec(player, context)
-	else
-		craftguide:get_formspec(player_name)
-	end
-end
-
-local function init_datas(user, name)
-	datas[name] = {filter = "", pagenum = 1, iX = sfinv_only and 8 or DEFAULT_SIZE}
-	if progressive_mode then
-		craftguide:get_filter_items(datas[name], user)
-	end
-end
-
-local function add_custom_recipes(item, recipes)
-	for j = 1, #craftguide.custom_crafts do
-		local craft = craftguide.custom_crafts[j]
-		if craft.output:match("%S*") == item then
-			recipes[#recipes + 1] = {
-				width  = craftguide.craft_types[craft.type].width,
-				type   = craft.type,
-				items  = craft.items,
-				output = craft.output,
-			}
-		end
-	end
-
-	return recipes
-end
-
-function craftguide:group_to_item(item)
+local function group_to_item(item)
 	if item:sub(1,6) == "group:" then
 		local itemsub = item:sub(7)
 		if group_stereotypes[itemsub] then
@@ -161,7 +129,7 @@ function craftguide:group_to_item(item)
 	return item:sub(1,6) == "group:" and "" or item
 end
 
-function craftguide:get_tooltip(item, recipe_type, cooktime, groups)
+local function get_tooltip(item, recipe_type, cooktime, groups)
 	local tooltip, item_desc = "tooltip[" .. item .. ";", ""
 	local fueltime = get_fueltime(item)
 	local has_extras = groups or recipe_type == "cooking" or fueltime > 0
@@ -198,7 +166,7 @@ function craftguide:get_tooltip(item, recipe_type, cooktime, groups)
 	return has_extras and tooltip .. "]" or ""
 end
 
-function craftguide:get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
+local function _get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 	local formspec, recipes_total = "", #recipes
 	if recipes_total > 1 then
 		formspec = formspec ..
@@ -246,8 +214,8 @@ function craftguide:get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 
 			local groups = extract_groups(v)
 			local label = groups and "\nG" or ""
-			local item_r = self:group_to_item(v)
-			local tltip = self:get_tooltip(item_r, recipe_type, cooktime, groups)
+			local item_r = group_to_item(v)
+			local tltip = get_tooltip(item_r, recipe_type, cooktime, groups)
 
 			formspec = formspec ..
 				"item_image_button[" .. X .. "," ..
@@ -259,7 +227,7 @@ function craftguide:get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 		BUTTON_SIZE = 1.1
 	end
 
-	local custom_recipe = self.craft_types[recipe_type]
+	local custom_recipe = craftguide.craft_types[recipe_type]
 	if recipe_type == "cooking" or (recipe_type == "normal" and width == 0) or
 			custom_recipe then
 		local icon   = recipe_type == "cooking" and "furnace" or "shapeless"
@@ -293,7 +261,7 @@ function craftguide:get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 				BUTTON_SIZE .. "," .. BUTTON_SIZE .. ";" ..
 				output .. ";" .. output_s .. ";]" ..
 
-		self:get_tooltip(output_s)
+		get_tooltip(output_s)
 
 	if output_is_fuel then
 		formspec = formspec ..
@@ -309,7 +277,7 @@ function craftguide:get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 	return formspec
 end
 
-function craftguide:get_formspec(player_name)
+local function get_formspec(player_name)
 	local data = datas[player_name]
 	local iY = sfinv_only and 4 or data.iX - 5
 	local ipp = data.iX * iY
@@ -385,7 +353,7 @@ function craftguide:get_formspec(player_name)
 					(iY + (sfinv_only and 2.85 or 2.35)) ..
 					";0.9,0.7;craftguide_arrow.png]" ..
 
-				self:get_tooltip(data.item) ..
+				get_tooltip(data.item) ..
 
 				"image[" .. (X + 2.1) .. "," ..
 					(iY + (sfinv_only and 2.68 or 2.18)) ..
@@ -393,7 +361,7 @@ function craftguide:get_formspec(player_name)
 		else
 			local show_usage = data.show_usage
 			formspec = formspec ..
-				self:get_recipe(data.iX,
+				_get_recipe(data.iX,
 						iY,
 						xoffset,
 						data.rnum,
@@ -411,7 +379,16 @@ function craftguide:get_formspec(player_name)
 	end
 end
 
-function craftguide:recipe_in_inv(inv, item_name, recipes_f)
+local show_fs = function(player, player_name)
+	if sfinv_only then
+		local context = sfinv.get_or_create_context(player)
+		sfinv.set_player_inventory_formspec(player, context)
+	else
+		get_formspec(player_name)
+	end
+end
+
+local function recipe_in_inv(inv, item_name, recipes_f)
 	local recipes = recipes_f or get_recipes(item_name) or {}
 	local show_item_recipes = {}
 
@@ -442,50 +419,7 @@ function craftguide:recipe_in_inv(inv, item_name, recipes_f)
 	return recipes, in_table(show_item_recipes)
 end
 
-function craftguide:get_init_items()
-	local items_list, c = {}, 0
-	local function list(name)
-		c = c + 1
-		items_list[c] = name
-	end
-
-	for name, def in pairs(reg_items) do
-		local is_fuel = get_fueltime(name) > 0
-		if (not (def.groups.not_in_craft_guide == 1 or
-			 def.groups.not_in_creative_inventory == 1)) and
-		        (get_recipe(name).items or is_fuel) and
-			 def.description and def.description ~= "" then
-				list(name)
-		end
-	end
-
-	for i = 1, #self.custom_crafts do
-		local craft  = self.custom_crafts[i]
-		local output = craft.output:match("%S*")
-		local listed
-
-		for j = 1, #items_list do
-			local listed_item = items_list[j]
-			if output == listed_item then
-				listed = true
-				break
-			end
-		end
-
-		if not listed then
-			list(output)
-		end
-	end
-
-	sort(items_list)
-	datas.init_items = items_list
-end
-
-mt.register_on_mods_loaded(function()
-	craftguide:get_init_items()
-end)
-
-function craftguide:get_filter_items(data, player)
+local function get_filter_items(data, player)
 	local filter = data.filter
 	if datas.searches[filter] then
 		data.items = datas.searches[filter]
@@ -506,7 +440,7 @@ function craftguide:get_filter_items(data, player)
 				filtered_list[counter] = item
 			end
 		elseif progressive_mode then
-			local _, has_item = self:recipe_in_inv(inv, item)
+			local _, has_item = recipe_in_inv(inv, item)
 			if has_item then
 				counter = counter + 1
 				filtered_list[counter] = item
@@ -530,7 +464,73 @@ function craftguide:get_filter_items(data, player)
 	data.items = filtered_list
 end
 
-function craftguide:get_item_usages(item)
+local function init_datas(user, name)
+	datas[name] = {filter = "", pagenum = 1, iX = sfinv_only and 8 or DEFAULT_SIZE}
+	if progressive_mode then
+		get_filter_items(datas[name], user)
+	end
+end
+
+local function add_custom_recipes(item, recipes)
+	for j = 1, #craftguide.custom_crafts do
+		local craft = craftguide.custom_crafts[j]
+		if craft.output:match("%S*") == item then
+			recipes[#recipes + 1] = {
+				width  = craftguide.craft_types[craft.type].width,
+				type   = craft.type,
+				items  = craft.items,
+				output = craft.output,
+			}
+		end
+	end
+
+	return recipes
+end
+
+local function get_init_items()
+	local items_list, c = {}, 0
+	local function list(name)
+		c = c + 1
+		items_list[c] = name
+	end
+
+	for name, def in pairs(reg_items) do
+		local is_fuel = get_fueltime(name) > 0
+		if (not (def.groups.not_in_craft_guide == 1 or
+			 def.groups.not_in_creative_inventory == 1)) and
+		        (get_recipe(name).items or is_fuel) and
+			 def.description and def.description ~= "" then
+				list(name)
+		end
+	end
+
+	for i = 1, #craftguide.custom_crafts do
+		local craft  = craftguide.custom_crafts[i]
+		local output = craft.output:match("%S*")
+		local listed
+
+		for j = 1, #items_list do
+			local listed_item = items_list[j]
+			if output == listed_item then
+				listed = true
+				break
+			end
+		end
+
+		if not listed then
+			list(output)
+		end
+	end
+
+	sort(items_list)
+	datas.init_items = items_list
+end
+
+mt.register_on_mods_loaded(function()
+	get_init_items()
+end)
+
+local function get_item_usages(item)
 	local usages = {}
 	for name, def in pairs(reg_items) do
 		if not (def.groups.not_in_craft_guide == 1 or
@@ -591,7 +591,7 @@ local function get_fields(player, ...)
 			fields.filter ~= "" then
 		data.filter = fields.filter:lower()
 		data.pagenum = 1
-		craftguide:get_filter_items(data, player)
+		get_filter_items(data, player)
 		show_fs(player, player_name)
 
 	elseif fields.prev or fields.next then
@@ -625,7 +625,7 @@ local function get_fields(player, ...)
 			if not next(recipes) and not is_fuel then return end
 
 			if not data.show_usage and item == data.item and not progressive_mode then
-				data.usages = craftguide:get_item_usages(item)
+				data.usages = get_item_usages(item)
 				if next(data.usages) then
 					data.show_usage = true
 					data.rnum = 1
@@ -635,8 +635,8 @@ local function get_fields(player, ...)
 			else
 				if progressive_mode then
 					local inv = player:get_inventory()
-					local recipes, has_item =
-						craftguide:recipe_in_inv(inv, item, recipes)
+					local has_item
+					recipes, has_item = recipe_in_inv(inv, item, recipes)
 					if not has_item then return end
 				end
 
@@ -661,7 +661,7 @@ if sfinv_only then
 			return sfinv.make_formspec(
 				player,
 				context,
-				craftguide:get_formspec(player_name)
+				get_formspec(player_name)
 			)
 		end,
 		on_enter = function(self, player, context)
@@ -679,13 +679,13 @@ if sfinv_only then
 else
 	mt.register_on_player_receive_fields(get_fields)
 
-	function craftguide:on_use(itemstack, user)
+	local function on_use(itemstack, user)
 		local player_name = user:get_player_name()
 		local data = datas[player_name]
 
 		if progressive_mode or not data then
 			init_datas(user, player_name)
-			self:get_formspec(player_name)
+			get_formspec(player_name)
 		else
 			show_formspec(player_name, "craftguide", data.formspec)
 		end
@@ -698,7 +698,7 @@ else
 		stack_max = 1,
 		groups = {book = 1},
 		on_use = function(itemstack, user)
-			craftguide:on_use(itemstack, user)
+			on_use(itemstack, user)
 		end
 	})
 
@@ -723,7 +723,7 @@ else
 			meta:set_string("infotext", S("Crafting Guide Sign"))
 		end,
 		on_rightclick = function(pos, node, user, itemstack)
-			craftguide:on_use(itemstack, user)
+			on_use(itemstack, user)
 		end
 	})
 
@@ -750,17 +750,17 @@ else
 		recipe = "craftguide:sign",
 		burntime = 10
 	})
-end
 
-if rawget(_G, "sfinv_buttons") then
-	sfinv_buttons.register_button("craftguide", {
-		title = S("Crafting Guide"),
-		tooltip = S("Shows a list of available crafting recipes, cooking recipes and fuels"),
-		action = function(player)
-			craftguide:on_use(nil, player)
-		end,
-		image = "craftguide_book.png",
-	})
+	if rawget(_G, "sfinv_buttons") then
+		sfinv_buttons.register_button("craftguide", {
+			title = S("Crafting Guide"),
+			tooltip = S("Shows a list of available crafting recipes, cooking recipes and fuels"),
+			action = function(player)
+				on_use(nil, player)
+			end,
+			image = "craftguide_book.png",
+		})
+	end
 end
 
 if not progressive_mode then

From 74a2750a4d982439a2edb8955166f765bcd8e216 Mon Sep 17 00:00:00 2001
From: Jean-Patrick Guerrero <jeanpatrick.guerrero@gmail.com>
Date: Mon, 17 Dec 2018 01:09:32 +0100
Subject: [PATCH 5/8] Fix tooltip

---
 README.md | 2 +-
 init.lua  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/README.md b/README.md
index 0eb6c64..536a1e5 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@ craftguide.register_craft_type("digging", {
 ```Lua
 craftguide.register_craft({
 	type   = "digging",
-	output = "default:cobble",
+	output = "default:cobble 2",
 	items  = {"default:stone"},
 })
 ```
diff --git a/init.lua b/init.lua
index cda282a..b55e57f 100644
--- a/init.lua
+++ b/init.lua
@@ -221,7 +221,7 @@ local function _get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 				"item_image_button[" .. X .. "," ..
 					(Y + (sfinv_only and 0.7 or 0.2)) .. ";" ..
 					BUTTON_SIZE .. "," .. BUTTON_SIZE .. ";" .. item_r ..
-					";" .. item_r .. ";" .. label .. "]" .. tltip
+					";" .. item_r:match("%S*") .. ";" .. label .. "]" .. tltip
 		end
 
 		BUTTON_SIZE = 1.1

From 783a84d3c6aa665aab8fb9927726e37e1b7c477f Mon Sep 17 00:00:00 2001
From: Jean-Patrick Guerrero <jeanpatrick.guerrero@gmail.com>
Date: Mon, 17 Dec 2018 19:15:28 +0100
Subject: [PATCH 6/8] Define custom recipe's width inside craft declaration

---
 README.md | 6 +++---
 init.lua  | 6 +++---
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/README.md b/README.md
index 536a1e5..00e6054 100644
--- a/README.md
+++ b/README.md
@@ -20,9 +20,8 @@ Use the command `/craft` to show the recipe(s) of the pointed node.
 #### Registering a custom crafting type ####
 ```Lua
 craftguide.register_craft_type("digging", {
-	description = S("Digging"),
-	icon  = "default_tool_steelpick.png",
-	width = 1,
+	description = "Digging",
+	icon = "default_tool_steelpick.png",
 })
 ```
 
@@ -30,6 +29,7 @@ craftguide.register_craft_type("digging", {
 ```Lua
 craftguide.register_craft({
 	type   = "digging",
+	width  = 1,
 	output = "default:cobble 2",
 	items  = {"default:stone"},
 })
diff --git a/init.lua b/init.lua
index b55e57f..1f245f5 100644
--- a/init.lua
+++ b/init.lua
@@ -55,8 +55,7 @@ end
 
 craftguide.register_craft_type("digging", {
 	description = S("Digging"),
-	icon  = "default_tool_steelpick.png",
-	width = 1,
+	icon = "default_tool_steelpick.png",
 })
 
 function craftguide.register_craft(def)
@@ -65,6 +64,7 @@ end
 
 craftguide.register_craft({
 	type   = "digging",
+	width  = 1,
 	output = "default:cobble",
 	items  = {"default:stone"},
 })
@@ -476,8 +476,8 @@ local function add_custom_recipes(item, recipes)
 		local craft = craftguide.custom_crafts[j]
 		if craft.output:match("%S*") == item then
 			recipes[#recipes + 1] = {
-				width  = craftguide.craft_types[craft.type].width,
 				type   = craft.type,
+				width  = craft.width,
 				items  = craft.items,
 				output = craft.output,
 			}

From f188580b8c583c6b37d06d844bb0220189d7ebd6 Mon Sep 17 00:00:00 2001
From: Jean-Patrick Guerrero <jeanpatrick.guerrero@gmail.com>
Date: Mon, 17 Dec 2018 22:48:53 +0100
Subject: [PATCH 7/8] Correct checking

---
 init.lua | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/init.lua b/init.lua
index 1f245f5..b5f16d5 100644
--- a/init.lua
+++ b/init.lua
@@ -190,7 +190,7 @@ local function _get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 	local rows = ceil(maxn(items) / width)
 	local rightest, s_btn_size = 0
 
-	if recipe_type ~= "fuel" and (width > GRID_LIMIT or rows > GRID_LIMIT) then
+	if recipe_type ~= "cooking" and (width > GRID_LIMIT or rows > GRID_LIMIT) then
 		formspec = formspec ..
 			"label[" .. ((iX / 2) - 2) .. "," .. (iY + 2.2) .. ";" ..
 				S("Recipe is too big to be displayed (@1x@2)", width, rows) .. "]"
@@ -201,7 +201,7 @@ local function _get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 				 (sfinv_only and 0 or 0.2)
 			local Y = ceil(i / width + (iY + 2) - min(2, rows))
 
-			if recipe_type ~= "fuel" and (width > 3 or rows > 3) then
+			if recipe_type ~= "cooking" and (width > 3 or rows > 3) then
 				BUTTON_SIZE = width > 3 and 3 / width or 3 / rows
 				s_btn_size = BUTTON_SIZE
 				X = BUTTON_SIZE * (i % width) + xoffset - 2.65

From e1eedb69bba72659c696541eb612cb9a4d27d151 Mon Sep 17 00:00:00 2001
From: Jean-Patrick Guerrero <jeanpatrick.guerrero@gmail.com>
Date: Wed, 19 Dec 2018 18:36:09 +0100
Subject: [PATCH 8/8] Minor optimization

---
 init.lua | 187 +++++++++++++++++++++++++++----------------------------
 1 file changed, 91 insertions(+), 96 deletions(-)

diff --git a/init.lua b/init.lua
index b5f16d5..f6c7153 100644
--- a/init.lua
+++ b/init.lua
@@ -21,7 +21,7 @@ craftguide.intllib = S
 
 -- Lua 5.3 removed `table.maxn`, use this alternative in case of breakage:
 -- https://github.com/kilbith/xdecor/blob/master/handlers/helpers.lua#L1
-local remove, maxn, sort = table.remove, table.maxn, table.sort
+local remove, maxn, sort, concat = table.remove, table.maxn, table.sort, table.concat
 local vector_add, vector_mul = vector.add, vector.multiply
 local min, max, floor, ceil = math.min, math.max, math.floor, math.ceil
 
@@ -167,13 +167,12 @@ local function get_tooltip(item, recipe_type, cooktime, groups)
 end
 
 local function _get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
-	local formspec, recipes_total = "", #recipes
+	local fs, recipes_total = {}, #recipes
 	if recipes_total > 1 then
-		formspec = formspec ..
-			"button[" .. (iX - (sfinv_only and 2.2 or 2.6)) .. "," ..
-				(iY + (sfinv_only and 3.9 or 3.3)) .. ";2.2,1;alternate;" ..
-				(show_usage and S("Usage") or S("Recipe")) .. " " ..
-				S("@1 of @2", recipe_num, recipes_total) .. "]"
+		fs[#fs + 1] = "button[" .. (iX - (sfinv_only and 2.2 or 2.6)) .. "," ..
+			(iY + (sfinv_only and 3.9 or 3.3)) .. ";2.2,1;alternate;" ..
+			(show_usage and S("Usage") or S("Recipe")) .. " " ..
+			S("@1 of @2", recipe_num, recipes_total) .. "]"
 	end
 
 	local recipe_type = recipes[recipe_num].type
@@ -191,10 +190,10 @@ local function _get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 	local rightest, s_btn_size = 0
 
 	if recipe_type ~= "cooking" and (width > GRID_LIMIT or rows > GRID_LIMIT) then
-		formspec = formspec ..
-			"label[" .. ((iX / 2) - 2) .. "," .. (iY + 2.2) .. ";" ..
-				S("Recipe is too big to be displayed (@1x@2)", width, rows) .. "]"
-		return formspec
+		fs[#fs + 1] = "label[" .. ((iX / 2) - 2) .. "," .. (iY + 2.2) .. ";" ..
+			S("Recipe is too big to be displayed (@1x@2)", width, rows) .. "]"
+
+		return concat(fs)
 	else
 		for i, v in pairs(items) do
 			local X = ceil((i - 1) % width + xoffset - width) -
@@ -217,11 +216,10 @@ local function _get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 			local item_r = group_to_item(v)
 			local tltip = get_tooltip(item_r, recipe_type, cooktime, groups)
 
-			formspec = formspec ..
-				"item_image_button[" .. X .. "," ..
-					(Y + (sfinv_only and 0.7 or 0.2)) .. ";" ..
-					BUTTON_SIZE .. "," .. BUTTON_SIZE .. ";" .. item_r ..
-					";" .. item_r:match("%S*") .. ";" .. label .. "]" .. tltip
+			fs[#fs + 1] = "item_image_button[" .. X .. "," ..
+				(Y + (sfinv_only and 0.7 or 0.2)) .. ";" ..
+				BUTTON_SIZE .. "," .. BUTTON_SIZE .. ";" .. item_r ..
+				";" .. item_r:match("%S*") .. ";" .. label .. "]" .. tltip
 		end
 
 		BUTTON_SIZE = 1.1
@@ -235,13 +233,13 @@ local function _get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 			       (iY + (sfinv_only and 2.2 or 1.7)) ..
 			       ";0.5,0.5;"
 
-		formspec = formspec ..
-			"image[" .. coords ..
-				(custom_recipe and custom_recipe.icon or
-				 "craftguide_" .. icon .. ".png^[resize:16x16") .. "]" ..
-			"tooltip[" .. coords ..
-				(custom_recipe and custom_recipe.description or
-					recipe_type:gsub("^%l", string.upper)) .. "]"
+		fs[#fs + 1] = "image[" .. coords ..
+			(custom_recipe and custom_recipe.icon or
+			 "craftguide_" .. icon .. ".png^[resize:16x16") .. "]"
+
+		fs[#fs + 1] = "tooltip[" .. coords ..
+			(custom_recipe and custom_recipe.description or
+			 recipe_type:gsub("^%l", string.upper)) .. "]"
 	end
 
 	local output   = recipes[recipe_num].output
@@ -251,30 +249,28 @@ local function _get_recipe(iX, iY, xoffset, recipe_num, recipes, show_usage)
 	local arrow_X  = rightest + (s_btn_size or BUTTON_SIZE)
 	local output_X = arrow_X + 0.9
 
-	formspec = formspec ..
-		"image[" .. arrow_X .. "," ..
-			(iY + (sfinv_only and 2.85 or 2.35)) ..
-			";0.9,0.7;craftguide_arrow.png]" ..
+	fs[#fs + 1] = "image[" .. arrow_X .. "," ..
+		(iY + (sfinv_only and 2.85 or 2.35)) ..
+		";0.9,0.7;craftguide_arrow.png]"
 
-		"item_image_button[" .. output_X .. "," ..
-				(iY + (sfinv_only and 2.7 or 2.2)) .. ";" ..
-				BUTTON_SIZE .. "," .. BUTTON_SIZE .. ";" ..
-				output .. ";" .. output_s .. ";]" ..
+	fs[#fs + 1] = "item_image_button[" .. output_X .. "," ..
+		(iY + (sfinv_only and 2.7 or 2.2)) .. ";" ..
+		BUTTON_SIZE .. "," .. BUTTON_SIZE .. ";" ..
+		output .. ";" .. output_s .. ";]"
 
-		get_tooltip(output_s)
+	fs[#fs + 1] = get_tooltip(output_s)
 
 	if output_is_fuel then
-		formspec = formspec ..
-			"image[" .. (output_X + 1) .. "," ..
-				(iY + (sfinv_only and 2.83 or 2.33)) ..
-				";0.6,0.4;craftguide_arrow.png]" ..
+		fs[#fs + 1] = "image[" .. (output_X + 1) .. "," ..
+			(iY + (sfinv_only and 2.83 or 2.33)) ..
+			";0.6,0.4;craftguide_arrow.png]"
 
-			"image[" .. (output_X + 1.6) .. "," ..
-				(iY + (sfinv_only and 2.68 or 2.18)) ..
-				";0.6,0.6;craftguide_fire.png]"
+		fs[#fs + 1] = "image[" .. (output_X + 1.6) .. "," ..
+			(iY + (sfinv_only and 2.68 or 2.18)) ..
+			";0.6,0.6;craftguide_fire.png]"
 	end
 
-	return formspec
+	return concat(fs)
 end
 
 local function get_formspec(player_name)
@@ -288,42 +284,42 @@ local function get_formspec(player_name)
 
 	data.pagemax = max(1, ceil(#data.items / ipp))
 
-	local formspec = ""
+	local fs = {}
 	if not sfinv_only then
-		formspec = formspec ..
-			"size[" .. (data.iX - 0.35) .. "," .. (iY + 4) .. ";]" ..
-			"background[1,1;1,1;craftguide_bg.png;true]" ..
-			"tooltip[size_inc;" .. S("Increase window size") .. "]" ..
-			"tooltip[size_dec;" .. S("Decrease window size") .. "]" ..
-			"image_button[" .. (data.iX * 0.47) ..
-				",0.12;0.8,0.8;craftguide_zoomin_icon.png;size_inc;]" ..
-			"image_button[" .. ((data.iX * 0.47) + 0.6) ..
+		fs[#fs + 1] = "size[" .. (data.iX - 0.35) .. "," .. (iY + 4) .. ";]"
+		fs[#fs + 1] = "background[1,1;1,1;craftguide_bg.png;true]"
+		fs[#fs + 1] = "tooltip[size_inc;" .. S("Increase window size") .. "]"
+		fs[#fs + 1] = "tooltip[size_dec;" .. S("Decrease window size") .. "]"
+		fs[#fs + 1] = "image_button[" .. (data.iX * 0.47) ..
+				",0.12;0.8,0.8;craftguide_zoomin_icon.png;size_inc;]"
+		fs[#fs + 1] = "image_button[" .. ((data.iX * 0.47) + 0.6) ..
 				",0.12;0.8,0.8;craftguide_zoomout_icon.png;size_dec;]"
 	end
 
-	formspec = formspec .. [[
-			image_button[2.4,0.12;0.8,0.8;craftguide_search_icon.png;search;]
-			image_button[3.05,0.12;0.8,0.8;craftguide_clear_icon.png;clear;]
-			field_close_on_enter[filter;false]
-		]] ..
-			"tooltip[search;" .. S("Search") .. "]" ..
-			"tooltip[clear;" .. S("Reset") .. "]" ..
-			"tooltip[prev;" .. S("Previous page") .. "]" ..
-			"tooltip[next;" .. S("Next page") .. "]" ..
-			"image_button[" .. (data.iX - (sfinv_only and 2.6 or 3.1)) ..
-				",0.12;0.8,0.8;craftguide_prev_icon.png;prev;]" ..
-			"label[" .. (data.iX - (sfinv_only and 1.7 or 2.2)) .. ",0.22;" ..
-				colorize(data.pagenum) .. " / " .. data.pagemax .. "]" ..
-			"image_button[" .. (data.iX - (sfinv_only and 0.7 or 1.2) -
-				(data.iX >= 11 and 0.08 or 0)) ..
-				",0.12;0.8,0.8;craftguide_next_icon.png;next;]" ..
-			"field[0.3,0.32;2.5,1;filter;;" .. mt.formspec_escape(data.filter) .. "]"
+	fs[#fs + 1] = [[
+		image_button[2.4,0.12;0.8,0.8;craftguide_search_icon.png;search;]
+		image_button[3.05,0.12;0.8,0.8;craftguide_clear_icon.png;clear;]
+		field_close_on_enter[filter;false]
+	]]
+
+	fs[#fs + 1] = "tooltip[search;" .. S("Search") .. "]"
+	fs[#fs + 1] = "tooltip[clear;" .. S("Reset") .. "]"
+	fs[#fs + 1] = "tooltip[prev;" .. S("Previous page") .. "]"
+	fs[#fs + 1] = "tooltip[next;" .. S("Next page") .. "]"
+	fs[#fs + 1] = "image_button[" .. (data.iX - (sfinv_only and 2.6 or 3.1)) ..
+			",0.12;0.8,0.8;craftguide_prev_icon.png;prev;]"
+	fs[#fs + 1] = "label[" .. (data.iX - (sfinv_only and 1.7 or 2.2)) .. ",0.22;" ..
+			colorize(data.pagenum) .. " / " .. data.pagemax .. "]"
+	fs[#fs + 1] = "image_button[" .. (data.iX - (sfinv_only and 0.7 or 1.2) -
+			(data.iX >= 11 and 0.08 or 0)) ..
+			",0.12;0.8,0.8;craftguide_next_icon.png;next;]"
+	fs[#fs + 1] = "field[0.3,0.32;2.5,1;filter;;" .. mt.formspec_escape(data.filter) .. "]"
 
 	local xoffset = data.iX / 2.15
 
 	if not next(data.items) then
-		formspec = formspec ..
-			"label[" .. ((data.iX / 2) - 1) .. ",2;" .. S("No item to show") .. "]"
+		fs[#fs + 1] = "label[" .. ((data.iX / 2) - 1) ..
+				",2;" .. S("No item to show") .. "]"
 	end
 
 	local first_item = (data.pagenum - 1) * ipp
@@ -333,49 +329,48 @@ local function get_formspec(player_name)
 		local X = i % data.iX
 		local Y = (i % ipp - X) / data.iX + 1
 
-		formspec = formspec ..
-			"item_image_button[" ..
-				(X - (sfinv_only and 0 or (X * 0.05))) .. "," ..
-				Y .. ";" .. BUTTON_SIZE .. "," .. BUTTON_SIZE .. ";" ..
-				name .. ";" .. name .. "_inv;]"
+		fs[#fs + 1] = "item_image_button[" ..
+			(X - (sfinv_only and 0 or (X * 0.05))) .. "," ..
+			Y .. ";" .. BUTTON_SIZE .. "," .. BUTTON_SIZE .. ";" ..
+			name .. ";" .. name .. "_inv;]"
 	end
 
 	if data.item and reg_items[data.item] then
 		if not data.recipes_item or (data.fuel and not get_recipe(data.item).items) then
 			local X = floor(xoffset) - (sfinv_only and 0 or 0.2)
-			formspec = formspec ..
-				"item_image_button[" .. X .. "," ..
-					(iY + (sfinv_only and 2.7 or 2.2)) ..
-					";" .. BUTTON_SIZE .. "," .. BUTTON_SIZE ..
-					";" .. data.item .. ";" .. data.item .. ";]" ..
 
-				"image[" .. (X + 1.1) .. "," ..
-					(iY + (sfinv_only and 2.85 or 2.35)) ..
-					";0.9,0.7;craftguide_arrow.png]" ..
+			fs[#fs + 1] = "item_image_button[" .. X .. "," ..
+				(iY + (sfinv_only and 2.7 or 2.2)) ..
+				";" .. BUTTON_SIZE .. "," .. BUTTON_SIZE ..
+				";" .. data.item .. ";" .. data.item .. ";]"
 
-				get_tooltip(data.item) ..
+			fs[#fs + 1] = "image[" .. (X + 1.1) .. "," ..
+				(iY + (sfinv_only and 2.85 or 2.35)) ..
+				";0.9,0.7;craftguide_arrow.png]"
 
-				"image[" .. (X + 2.1) .. "," ..
-					(iY + (sfinv_only and 2.68 or 2.18)) ..
-					";1.1,1.1;craftguide_fire.png]"
+			fs[#fs + 1] = get_tooltip(data.item)
+
+			fs[#fs + 1] = "image[" .. (X + 2.1) .. "," ..
+				(iY + (sfinv_only and 2.68 or 2.18)) ..
+				";1.1,1.1;craftguide_fire.png]"
 		else
-			local show_usage = data.show_usage
-			formspec = formspec ..
-				_get_recipe(data.iX,
-						iY,
-						xoffset,
-						data.rnum,
-						(show_usage and data.usages or data.recipes_item),
-						show_usage)
+			local usage = data.show_usage
+			fs[#fs + 1] = _get_recipe(data.iX,
+						  iY,
+						  xoffset,
+						  data.rnum,
+						  (usage and data.usages or data.recipes_item),
+						  usage)
 		end
 	end
 
-	data.formspec = formspec
+	fs = concat(fs)
+	data.formspec = fs
 
 	if sfinv_only then
-		return formspec
+		return fs
 	else
-		show_formspec(player_name, "craftguide", formspec)
+		show_formspec(player_name, "craftguide", fs)
 	end
 end