[PATCH 2/2] Add playersettings.reset to fall back to default

2 files changed, 59 insertions, 17 deletions

diff --git a/README b/README
index 294fc18..3dc239f 100644
--- a/README
+++ b/README
@@ -70,6 +70,13 @@ playersettings.set(player_name,setting_name,new_value)
 -- 'new_value' is the new value of the setting.
 -- Changing settings via this interface bypasses the built-in validation (such as range checking on numbers) but NOT any specified onchange or afterchange actions.
 
+To reset a setting:
+
+playersettings.reset(player_name,setting_name)
+-- 'player_name' is the player to change the setting for.
+-- 'setting_name' is the name of the setting to reset/clear.
+-- This will cause 'playersettings.get' to fall back to the default value.
+
 To get the value of a setting (from another mod):
 
 playersettings.get(player_name,setting_name)
diff --git a/init.lua b/init.lua
index 2bf67fb..86c116a 100644
--- a/init.lua
+++ b/init.lua
@@ -50,6 +50,8 @@ local function table_concat_escaped(list, delim)
 	return table.concat(esc, delim)
 end
 
+local setting_get_no_fallback -- (name, setting, require_existence)
+
 function playersettings.openform(player)
 	if type(player) == "string" then player = core.get_player_by_name(player) end
 	local name = player:get_player_name()
@@ -64,11 +66,17 @@ function playersettings.openform(player)
 		local technical = playersettings.show_technical_names[name]
 		for _,setting in ipairs(playersettings.settingslist) do
 			local def = playersettings.registered[setting]
+			local row
 			if technical then
-				table.insert(list, ("%s (%s)"):format(setting, def.type))
+				row = ("%s (%s)"):format(setting, def.type)
 			else
-				table.insert(list, def.shortdesc)
+				row = def.shortdesc
+			end
+			if (setting_get_no_fallback(name, setting, false)) ~= nil then
+				-- 'Value is set' indicator
+				row = row .. " *"
 			end
+			table.insert(list, row)
 		end
 		settingslist = table_concat_escaped(list, ",")
 	end
@@ -155,8 +163,7 @@ function playersettings.handleform(player,form,fields)
 	local settingname, def = get_setting_at(playersettings.highlighted[name])
 	if def then
 		if fields.breset then
-			local value = playersettings.getdefault(settingname)
-			playersettings.set(name, settingname, value)
+			playersettings.reset(name, settingname)
 			playersettings.openform(player)
 			return
 		end
@@ -208,12 +215,20 @@ function playersettings.getdefault(setting)
 	end
 end
 
-function playersettings.get(name,setting)
+--- Return #1: Value or `nil` if no value was found
+--- Return #2: Database key
+setting_get_no_fallback = function(name, setting, require_existence)
 	CHECK_TYPE("string", name, "player name")
 	CHECK_TYPE("string", setting, "setting name")
-	assert(playersettings.registered[setting],"No such setting: "..setting)
+	local key = ("%s|%s"):format(name, setting)
+	if require_existence then
+		assert(playersettings.registered[setting],"No such setting: "..setting)
+	end
+	return core.deserialize(storage:get_string(key)), key
+end
 
-	local value = core.deserialize(storage:get_string(string.format("%s|%s",name,setting)))
+function playersettings.get(name,setting)
+	local value = setting_get_no_fallback(name, setting, true)
 	if value ~= nil then
 		return value
 	else
@@ -222,13 +237,14 @@ function playersettings.get(name,setting)
 end
 
 function playersettings.set(name,setting,value)
-	CHECK_TYPE("string", name, "player name")
-	CHECK_TYPE("string", setting, "setting name")
-	assert(playersettings.registered[setting],"No such setting: "..setting)
-
-	local old = playersettings.get(name,setting)
-	if old == value then
-		return
+	local old, key = setting_get_no_fallback(name, setting, true)
+
+	-- Compare value without the .get(...) default fallback
+	local is_different = old ~= value
+	if old == nil then
+		local default = playersettings.getdefault(setting)
+		-- Allow using the default value but do not fire callbacks if they are equal
+		is_different = value ~= default
 	end
 
 	local def = playersettings.registered[setting]
@@ -238,11 +254,30 @@ function playersettings.set(name,setting,value)
 			return
 		end
 	end
-	if def.onchange then
+	if is_different and def.onchange then
 		if not def.onchange(name,old,value) then return end
 	end
-	storage:set_string(string.format("%s|%s",name,setting),core.serialize(value))
-	if def.afterchange then def.afterchange(name,old,value) end
+	storage:set_string(key,core.serialize(value))
+	if is_different and def.afterchange then
+		def.afterchange(name,old,value)
+	end
+end
+
+function playersettings.reset(name, setting)
+	local old, key = setting_get_no_fallback(name, setting, false)
+	-- ^ 'false': Do not require 'setting' to be defined to allow removing unused settings.
+
+	local def = playersettings.registered[setting]
+	local default      = def and playersettings.getdefault(setting)
+	local is_different = def and old ~= default
+
+	if is_different and def.onchange then
+		if not def.onchange(name,old,default) then return end
+	end
+	storage:set_string(key, "")
+	if is_different and def.afterchange then
+		def.afterchange(name,old,default)
+	end
 end
 
 function playersettings.register(setting,def)