signal

Named events, available at xiao.signal. A callback is registered under a signal name and an identity. Registering the same identity again replaces its callback. Callbacks run in the order their identity was first added.

Signals are shared by every execution in the VM, so one script can fire a signal another script listens to. An error raised in a callback during xiao.signal.call goes back to the caller like any Lua error.

Functions

xiao.signal.add(name: string, identity: any, callback: function)

xiao.signal.add(name: string, identity: any, callback: function)

Registers a callback under name and identity.
Registering the same identity again replaces its callback.

xiao.signal.remove(name: string, identity: any): boolean

xiao.signal.remove(name: string, identity: any): boolean

Returns true if the callback existed.

xiao.signal.get(name: string, identity: any): function | nil

xiao.signal.get(name: string, identity: any): function | nil

Returns the callback or nil.

xiao.signal.call(name: string, ...): any

xiao.signal.call(name: string, ...): any

Calls every callback of name with ....
Stops at the first callback that returns a non-nil value and returns its values.

xiao.signal.connect(name: string, callback: function, identity: any)

xiao.signal.connect(name: string, callback: function, identity: any)

Alias of xiao.signal.add, other argument order.

xiao.signal.disconnect(name: string, identity: any): boolean

xiao.signal.disconnect(name: string, identity: any): boolean

Alias of xiao.signal.remove.

xiao.signal.connection(name: string, identity: any): function | nil

xiao.signal.connection(name: string, identity: any): function | nil

Alias of xiao.signal.get.

xiao.signal.fire(name: string, ...): any

xiao.signal.fire(name: string, ...): any

Alias of xiao.signal.call.

Events

Signals fired by the client:

Name	Arguments	When
`think`	`dt` (seconds)	every frame, after `on_frame` and before the paint listeners (see xiao.paint)
`unload`	none	on Clear VM and when the client unloads, after `on_unload`

A callback that raises an error while the client fires it is removed and the error is printed in the console.

local elapsed = 0
xiao.signal.add("think", "timer", function(dt)
    elapsed = elapsed + dt
end)
xiao.signal.add("unload", "save", function()
    xiao.fs.write("elapsed.txt", tostring(elapsed))
end)