Callback Datums

A datum that holds a proc to be called on another object, used to track proccalls to other objects

USAGE

var/datum/callback/C = new(object|null, PROC_REF(procname), arg1, arg2, ... argn)
var/timerid = addtimer(C, time, timertype)
you can also use the compiler define shorthand
var/timerid = addtimer(CALLBACK(object|null, PROC_REF(procname), arg1, arg2, ... argn), time, timertype)

Note: proc strings can only be given for datum proc calls, global procs must be proc paths

Also proc strings are strongly advised against because they don't compile error if the proc stops existing

In some cases you can provide a shortform of the procname, see the proc typepath shortcuts documentation below

INVOKING THE CALLBACK

var/result = C.Invoke(args, to, add) additional args are added after the ones given when the callback was created

var/result = C.InvokeAsync(args, to, add) Asynchronous - returns . on the first sleep then continues on in the background after the sleep/block ends, otherwise operates normally.

PROC TYPEPATH SHORTCUTS

(these operate on paths, not types, so to these shortcuts, datum is NOT a parent of atom, etc...)

proc defined on current(src) object OR overridden at src or any of its parents:

PROC_REF(procname)

CALLBACK(src, PROC_REF(some_proc_here))

global proc

GLOBAL_PROC_REF(procname)

CALLBACK(src, GLOBAL_PROC_REF(some_proc_here))

proc defined on some type

TYPE_PROC_REF(/some/type/, some_proc_here)