Lua Predefined variables

---

_G -- returns a table of all global variables
coroutine -- returns a table containing functions for threads
debug -- returns a table containing debug functions
math -- returns a table that contains mathematical functions
string -- returns a table containing functions for strings
table -- returns a table that contains functions for tables
_VERSION -- returns a string of the version of lua in format "Lua 5.1"
self -- used in methods
arg -- used in functions which use '...' as an argument (https://www.lua.org/pil/5.2.html)

MTA Predefined variables

---

Global

shared

exports -- returns a table of resource names containing all export functions
resource -- returns a resource element of the resource the snippet was executed in
resourceRoot -- returns a resource root element of the resource the snippet was executed in
resourceName -- returns the name of the resource the snippet was executed in
root -- returns the root element of the server

client

guiRoot -- returns the root element of all GUI elements.
localPlayer -- returns the player element of the local player.

Event Handlers

More details about hidden variables in functions and events

shared

source -- The player or element the event was attached to
this -- Element, which was attached function-handler.
eventName -- the name of the event ("onResourceStart", "onPlayerWasted" etc.)
sourceResource -- the resource that called the event
sourceResourceRoot -- the root of the resource that called the event

server

client -- the client that called the event

Please note, the above pre-defined variables may only be accessible in the relevant scope (i.e, an event handler callback function). Further functions defined within that scope may not have access to these pre-defined variables at the time of their execution.

For this reason, you should always explicitly redefine pre-defined variables as local variables, to ensure they are always available to new functions declared within that scope - for example:

function init()
    local player = source -- source is a pre-defined variable for this event, containing the player element

    local func = function()
        print(source) -- prints 'nil', source isn't available anymore
        print(player) -- prints player element
    end

    setTimer(func, 1000, 1) -- run above function after 1 second
end
addEventHandler("onPlayerResourceStart", root, init)

Timer callbacks

shared

sourceTimer -- current timer in callback function.

HTTP

List Predefined variables available in the HTTP files (more info about it).

requestHeaders -- table, contains all HTTP headlines current page.
form -- table, contains all POST and GET settings, transferred current page.
cookies -- table, contains all COOKIE, transferred current page.
hostname -- string, contains IP or name host, which requested current page.
url -- string, URL current page.
user -- element, account user, which requested current page.

See Also

Reference

• Element tree