Lua Hook Library

hook.lua

--- A library used for calling and attaching hooks.
-- @module Hook

Hook = {}
local cachedHooks = {}

--- Attaches a function to a hook.
-- @string hookID The string ID of the hook to be attached to.
-- @string uniqueID The unique ID of the function you are attaching to the hook.
-- @func func The function to be called when the hook is called.
-- @usage Hook.Attach( "FooHook", "UniqueID", FunctionInput )
function Hook.Attach( hookID, uniqueID, func )
    if not cachedHooks[hookID] then
        cachedHooks[hookID] = {}
    end
    cachedHooks[hookID][uniqueID] = func
end

--- Calls all of a hook's attached functions.
-- @string hookID The name of the hook to call.
-- @param[type=varargs] ... The arguments you want to pass to the hook.
-- @return The value of the first hook that returns something.
-- @usage Hook.Call( "FooHook" )
function Hook.Call( hookID, ... )
    if cachedHooks[hookID] then
        local valueToReturn
        for k, v in pairs( cachedHooks[hookID] ) do
            local returnValue = v( ... )
            if returnValue ~= nil and valueToReturn == nil then valueToReturn = returnValue end
        end
        return valueToReturn
    end
end

--- Removes a hook attachment from it's table.
-- @string hookID The name of the hook to remove from.
-- @string uniqueID The hook you are removing.
-- @usage Hook.Remove( "FooHook", "UniqueID" )
function Hook.Remove( hookID, uniqueID )
    if cachedHooks and cachedHooks[hookID] and cachedHooks[hookID][uniqueID] then
        cachedHooks[hookID][uniqueID] = nil
    end
end

--- Returns a table of all the hooks.
-- @return The table of registered hooks.
-- @usage Hook.GetAll()
function Hook.GetAll()
    return cachedHooks
end