addEventHandler
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This function will add an event handler. An event handler is a function that will be called when the event it's attached to is triggered. See event system for more information on how the event system works.
You shouldn't re-use the same name for your handler function as the event name - if multiple handler functions are used, as this can lead to confusion. On the same note, for multiple reasons, it isn't a good idea to export the same functions that you use locally as remote event handlers.
See Event Source Element for a descriptive visualization of the event system handling an event trigger.
See Script security for how-to prevent cheaters from abusing event system and element data .
Anything bound to a specific element will be run before other handlers that are bound to something higher in the element tree (like root) This means that "high+10" bound to root won't trigger before "normal" bound directly to an element.
Due to the additional set of global variables, the event-trigger specific variables it is NOT a good idea to use the same function locally as well as directly as an event handler . Event handlers often make use of the source element variable which would often find no use in generic functions. Inside of server-side remote event handlers it is important to add protections against exploits due to unexpected client event triggers or network-based load situations while generic functions, due to being part of a controlled call-stack, do not in general face the same issues. It is recommended to adapt a good-natured distancing principle between code meant to run from local logic in separation to code meant to run from remote logic.
Syntax
addEventHandler ( )Code Examples
This serverside example sends a message to everyone in the server when a player spawns.
-- define our handler functionfunction onPlayerSpawnHandler ( ) -- get the player's name, source is the player because he was spawned local playerName = getPlayerName( source ) -- output in the chat box that they've spawned outputChatBox ( playerName .. " has spawned!" )end
addEventHandler( "onPlayerSpawn", root, onPlayerSpawnHandler ) -- root is a predefined global variable for getRootElement()