[Lua] Reload scripts in-game on the fly, ANY engine, ANY rev

[Dynashock]

Reloading a specified script in-game using a small Lua script


Content

• Introduction
• Which one to use?
• How to set it up
• How to use
• The script - utilizing a chat hook
• The script - utilizing a gossip script
• Extra information

Introduction
Are you one of those guys who uses a newer ArcEmu rev than 3089? Or are you one of those guys running a non-ArcEmu server with a Lua Engine? And are you wanting to reload a script in-game? Well, then this is for you.


Which one to use?
If you run a Lua engine which has a chat hook then I recommend the one with the chat hook as it's faster to type it immediately instead of having to open up a gossip and a codebox.
If you do not have a Lua engine with a chat hook then the gossip script is for you. Using the codebox you will be able to specify which script you want to load.


How to set it up?
If you're using the chat hook version then it's a simple matter of drag and drop in your scripts folder just as you would with any Lua script.
If you're using the gossip version you'll have to add a gossip item to your database first, change the ITEM_ID_GOES_HERE to the newly added item and add the Lua script to your scripts folder. Don't know how to make a gossip item? Then I point you in the direction of this guide: Sign In


How to use?
Using the chat hook version you can simply type: #ReloadScript <name of the script> . Thus if I have a script called "MyLua" in my scripts folder I type "#ReloadEngine MyLua".
The gossip script uses the codebox to ask for the script name. Thus if you have the codebox open and you have a script called "MyLua" you simply have to type "MyLua" in the codebox.


The script - utilizing a chat hook

function ReloadScript_ChatHook(event, player, message, type, language)
	local _, end_index = message:find("#ReloadScript")
	if (end_index) then
		local path = message:sub(end_index+2)
		if path ~= "" then
			player:SendBroadcastMessage("Reloading " .. path .. ".")
			dofile("scripts/" .. path .. ".lua")
		else
			player:SendBroadcastMessage("No specified file.")
		end
	end
end

RegisterServerHook(16, "ReloadScript_ChatHook")

The script - utilizing a gossip script

function ReloadLua_Trigger(item, event, player)
	item:GossipCreateMenu(50, player, 0)
	item:GossipMenuAddItem(0, "Reload script.", 1, 1)
	item:GossipMenuAddItem(0, "[Exit]", 2, 0)
	item:GossipSendMenu(player)
end

function ReloadLua_Select(item, event, player, id, intid, code)
	if (intid == 1) then
		if code ~= nil and code ~= "" then
			player:SendBroadcastMessage("Reloading " .. code .. ".")
			dofile("scripts/" .. code .. ".lua")
		else
			player:SendBroadcastMessage("No specified file.")
		end
		player:GossipComplete()
	end
	
	if (intid == 2) then
		player:GossipComplete()
	end
end

RegisterItemGossipEvent(ITEM_ID_GOES_HERE, 1, "ReloadLua_Trigger")
RegisterItemGossipEvent(ITEM_ID_GOES_HERE, 2, "ReloadLua_Select")

Extra information
What does dofile do?
The dofile(path) function is a standard function of the Lua interpreter. It immediately executes the specified path as a chunk in the Lua interpreter. Because Lua functions are anonymous reloading a script is basically nothing but assigning variables.


Anony-.. wut?
You heard that right, folks. Lua functions are anonymous. What does that mean? It means they actually do not have a name. But, but, if I do function myFunction() I'm giving it a name, am I not?
Yes and no. It's eye candy, because what you are actually doing is myFunction = function(). Thus declaring a function is nothing but assigning a function to a variable.


What's this _ thingie I noticed in "local _, end_index"?
That's called a dummy variable. Sometimes functions return more than one piece of information, but we don't need the others. By using the dummy variable we are basically deleting pieces of returned information and assigning the other information to the other specified variable, thus gaining memory effiency.

[stoneharry]

Not only a release that benefits everyone who uses Lua, but also explained very clearly about how it works and how to work it.

[Dr. Cheasterfield]

Oh such a good share !
Really useful ! +Rep

[Reflection]

Very nice! Outstanding script and presented well. +4

Nicely done

[Ground Zero]

Great release, so you did figure out how to fix this in the end. +6

[P1raten]

Rep worthy. +rep x3

[Proxes]

Great Job Very usefull

Rep for you buddy

[Claiver]

So few comments for such a revolutionary release, I mean, first I see this being able in Lua (regardless of the fact that I see this after what, 5 months?).
I never knew you wrote this, Dyna!

+Rep from me, to you.

[Breakdawn]

So this works with Mangos I guess? (: Or am I wrong?

[Trle94]

Its is for arcemu and arcemu bassed cores that support lua :P Good job Dynashock +Rep from me

[Confucius]

This is great for servers were you don't have access to the world.exe to do reloadscripts or only want to reload one script +Rep 4

[bendaferi]

Thank you I found this script really useful. Since I don't have to restart my server over and over again.
+Rep