core: implement safe_region

worldeditadditions_core/core/run_command.lua

@@ -1,5 +1,7 @@
 local we_c = worldeditadditions_core
 
+-- WARNING: safe_region MUST NOT be imported more than once, as it defines chat commands. If you want to import it again elsewhere, check first that multiple dofile() calls don't execute a file more than once.
+local safe_region = dofile(we_c.modpath.."/core/safe_region.lua")
 local human_size = dofile(we_c.modpath.."/core/lib/human_size.lua")
 
 -- TODO: Reimplement worldedit.player_notify(player_name, msg_text)
@@ -39,9 +41,9 @@ local function run_command(cmdname, options, player_name, paramtext)
 		
 		if potential_changes > limit then
 			worldedit.player_notify(player_name, "/"..cmdname.." "..paramtext.."' may affect up to "..human_size(potential_changes).." nodes. Type //y to continue, or //n to cancel (see the //saferegion command to control when this message appears).")
-			
-			-- TODO: Wrap run_command_stage2 in safe_region stuff
-			run_command_stage2(player_name, options.func, parse_result)
+			safe_region(player_name, cmdname, function()
+				run_command_stage2(player_name, options.func, parse_result)
+			end)
 		end
 	else
 		run_command_stage2(player_name, options.func, parse_result)

worldeditadditions_core/core/safe_region.lua

@@ -0,0 +1,65 @@
+
+-- ███████  █████  ███████ ███████     ██████  ███████  ██████  ██  ██████  ███    ██
+-- ██      ██   ██ ██      ██          ██   ██ ██      ██       ██ ██    ██ ████   ██
+-- ███████ ███████ █████   █████       ██████  █████   ██   ███ ██ ██    ██ ██ ██  ██
+--      ██ ██   ██ ██      ██          ██   ██ ██      ██    ██ ██ ██    ██ ██  ██ ██
+-- ███████ ██   ██ ██      ███████     ██   ██ ███████  ██████  ██  ██████  ██   ████
+
+local worldedit_command_y, worldedit_command_n
+
+if minetest.global_exists("worldedit") then
+	worldedit_command_y = minetest.registered_commands["/y"].func
+	worldedit_command_n = minetest.registered_commands["/n"].func
+end
+
+--- A table that holds at most 1 pending function call per player.
+local pending_calls = {}
+
+--- Captures the given function in the safe_region subsystem for later execution.
+-- @param	player_name		string		The name of the player.
+-- @param	cmdname			string		The name of the command being executed.
+-- @param	func			function	The function to execute later. Will be passed NO ARGUMENTS should it ever get executed in the future (this is not guaranteed).
+-- @returns	nil
+local function safe_region(player_name, cmdname, func)
+	pending_calls[player_name] = {
+		cmdname = cmdname,
+		func = func
+	}
+end
+
+minetest.override_chatcommand("/y", {
+	params = "",
+	description = "Run a pending operation that was captured by the safe region system earlier.",
+	func = function(player_name)
+		if pending_calls[player_name] == nil then
+			if minetest.global_exists("worldedit") and worldedit_command_y ~= nil then
+				worldedit_command_y(player_name)
+			else
+				worldedit.player_notify(player_name, "There aren't any pending operations at the moment.")
+			end
+		else
+			pending_calls[player_name].func()
+			pending_calls[player_name] = nil
+		end
+	end
+})
+
+minetest.override_chatcommand("/n", {
+	params = "",
+	description = "Abort a pending operation that was captured by the safe region system.",
+	func = function(player_name)
+		if pending_calls[player_name] == nil then
+			if minetest.global_exists("worldedit") and worldedit_command_y ~= nil then
+				worldedit_command_n(player_name)
+			else
+				worldedit.player_notify(player_name, "There aren't any operations pending, so there's nothing to abort.")
+			end
+		else
+			worldedit.player_notify(player_name, "Aborting captured command /"..pending_calls[player_name].cmdname..".")
+			pending_calls[player_name] = nil
+		end
+	end
+})
+
+
+return safe_region