Lua events

README.md

SIMPLE EVENTS FOR LUA

Description will be added later

event.lua

-- Subscription

local S = {}
S.__index = S

function S.new(previous, event, func, first_arg)
    local self = setmetatable({}, S)
    self._next = nil
    self._previous = previous
    self._is_active = true
    self._event = event
    self._func = func
    self._first_arg = first_arg
    return self
end

function S:_getNextActive()
    if self._is_active then return self._next end
    local s = self._previous
    while not s._is_active do s = s._previous end
    return s._next
end

function S:unsubscribe()
    if self._is_active then
        self._previous._next = self._next
        if self._next ~= nil then
            self._next._previous = self._previous
        end
        self._next = nil
        self._is_active = false
        self._event:_onDeactivated(self)
    end
end

function S:notify(args)
    if self._is_active then
        if self._first_arg then
            self._func(self._first_arg, unpack(args))
        else
            self._func(unpack(args))
        end
    end
end

-- Event

local E = {}
E.__index = E

function E.new()
    local self = setmetatable({}, E)
    self._first = S.new(nil, self, nil, false)
    self._last = self._first
    return self
end

function E:subscribe(func, first_arg)
    local s = S.new(self._last, self, func, first_arg)
    self._last._next = s
    self._last = s
    return s
end

function E:raise(...)
    local s = self._first._next
    while s do
        s:notify(arg)
        s = s:_getNextActive()
    end
end

function E:_onDeactivated(sub)
    if sub == self._last then
        self._last = sub.previous
    end
end

return E