update formspec handling accordsing to best practices https://forum.m…

…inetest.net/viewtopic.php?f=47&t=19129

api/formspec.lua

@@ -1,5 +1,5 @@
 local F = minetest.formspec_escape
-local string_to_pos = minetest.string_to_pos
+local show_formspec = minetest.show_formspec
 
 local S = smartshop.S
 local api = smartshop.api
@@ -18,9 +18,29 @@ local history_max = smartshop.settings.history_max
 
 --------------------
 
+local pos_by_player_name = {}
+
+function api.show_formspec(player, pos, formspec)
+	local player_name = player:get_player_name()
+	pos_by_player_name[player_name] = pos
+	show_formspec(player_name, "smartshop:form", formspec)
+end
+
+function api.close_formspec(player)
+	local player_name = player:get_player_name()
+	pos_by_player_name[player_name] = nil
+end
+
+minetest.register_on_leaveplayer(function(player)
+	api.close_formspec(player)
+end)
+
 function api.on_player_receive_fields(player, formname, fields)
-	local spos = formname:match("^smartshop:(.+)$")
-	local pos = spos and string_to_pos(spos)
+	if formname ~= "smartshop:form" then
+		return
+	end
+	local player_name = player:get_player_name()
+	local pos = pos_by_player_name[player_name]
 	local obj = api.get_object(pos)
 	if obj then
 		obj:receive_fields(player, fields)

api/shop_class.lua

@@ -1,7 +1,6 @@
 local get_node = minetest.get_node
 local parse_json = minetest.parse_json
 local pos_to_string = minetest.pos_to_string
-local show_formspec = minetest.show_formspec
 local swap_node = minetest.swap_node
 local write_json = minetest.write_json
 
@@ -505,10 +504,7 @@ function shop_class:show_formspec(player, force_client_view)
 		formspec = api.build_client_formspec(self)
 	end
 
-	local formname = ("smartshop:%s"):format(self:get_pos_as_string())
-	local player_name = player:get_player_name()
-
-	show_formspec(player_name, formname, formspec)
+	api.show_formspec(player, self.pos, formspec)
 end
 
 function shop_class:show_history(player)
@@ -517,10 +513,8 @@ function shop_class:show_history(player)
 	end
 
 	local formspec = api.build_history_formspec(self)
-	local formname = ("smartshop:%s"):format(self:get_pos_as_string())
-	local player_name = player:get_player_name()
 
-	show_formspec(player_name, formname, formspec)
+	api.show_formspec(player, self.pos, formspec)
 end
 
 local function get_buy_index(pressed)
@@ -535,7 +529,9 @@ function shop_class:receive_fields(player, fields)
 	local buy_index = get_buy_index(fields)
 	local changed = false
 
-	if buy_index then
+	if fields.quit then
+		api.close_formspec(player)
+	elseif buy_index then
 		api.try_purchase(player, self, buy_index)
 		self:show_formspec(player, true)
 	elseif self:is_owner(player) then

api/storage_class.lua

@@ -55,14 +55,17 @@ function storage_class:show_formspec(player)
 		return
 	end
 
-	local player_name = player:get_player_name()
 	local formspec = api.build_storage_formspec(self)
-	local formname = ("smartshop:%s"):format(self:get_pos_as_string())
 
-	minetest.show_formspec(player_name, formname, formspec)
+	api.show_formspec(player, self.pos, formspec)
 end
 
 function storage_class:receive_fields(player, fields)
+	if fields.quit then
+		api.close_formspec(player)
+		return
+	end
+
 	if not self:is_owner(player) then
 		return
 	end