Event module

Allows you to register new event callbacks when initializing mods.

See also

• core.event

Usage

local Event = ELONA.require("core.Event")

Functions

register (event_id, handler[, opts])	Registers a new event handler.
unregister (event_id, handler)	Unregisters an event handler that was previously registered with Event.register.
trigger (event[, data][, opts])	Triggers an event from a Lua script.

Functions

# register (event_id, handler[, opts])

Registers a new event handler.

This function will insert a new callback hander for the given event into the list of callback handlers for that event. Then, when the event is fired, each callback in the list will be run in the order in which they were registered. The callbacks will receive a single table argument containing the event's parameters. These parameters will differ between event types. Read the documentation for the event you're handling to see the available event arguments for it.

Optionally, a table of options can be passed. There are two parameters supported. priority determines the order in which the callback will run, with higher values being given priority. The default is 1000. instances is a table of objects that allow only running the event when certain instance parameters are received by the event, like a specific character or type. These parameters vary per event and not all events support them.

A given callback can only be registered once per event/instance.

Parameters:

• event_id : (string) the event kind to register
• handler : (function) the handler for this event
• opts : ({priority=num,instances=table}) Event options. (optional)

Usage:

local GUI = ELONA.require("core.GUI")
local Event = ELONA.require("core.Event")
local function my_chara_moved_handler(chara)
    GUI.txt("The character " .. chara.name .. " is about to move. ")
end

Event.register("core.character_moved", my_chara_moved_handler, { priority = 1000 })

# unregister (event_id, handler)

Unregisters an event handler that was previously registered with Event.register.

This has no effect if the handler was not already registered.

Parameters:

• event_id : (string) the event kind to unregister
• handler : (function) the previously registered handler

# trigger (event[, data][, opts])

Triggers an event from a Lua script.

You can pass a table of options containing an instances parameter to run instanced events as well as the non-instanced version. WARNING: This does not currently prevent infinite recursion!

Parameters:

• event : (string) the event to trigger
• data : (table) the event data (optional)
• opts : ({instances=table}) Event options (optional)