- Joined
- Sep 26, 2009
- Messages
- 9,534
Global Variable Remapper creates a new frontier for GUI interaction by providing a way to override normal "udg_" variables to instead run code when referenced or set.
Example 1 - Override "udg_RemovePoint" to remove any location that is assigned to it (actually, this pre-dates Lua-Infused GUI, which is - by far - the best memory leak solution ever created for GUI):
Changes from previous version
Unit Tests (can be run in ZeroBrane Studio)
Example 1 - Override "udg_RemovePoint" to remove any location that is assigned to it (actually, this pre-dates Lua-Infused GUI, which is - by far - the best memory leak solution ever created for GUI):
Lua:
GlobalRemap("udg_RemovePoint", nil, function(loc) RemoveLocation(loc) end)-
SomeTrig
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Events
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Conditions
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Actions
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Set TempPoint = (Point(0.00, 0.00))
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Set RemovePoint = TempPoint -------- Invokes the Lua code and calls RemoveLocation on "TempPoint"
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Lua:
do
local internalVar = "static"
GlobalRemap("udg_ReadonlyVar", function() return internalVar end, nil)
end-
SomeTrig
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Events
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Conditions
-
Actions
-
Game - Display to (All players) the text: (ReadonlyVar)
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-------- The above will display "static" --------
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Set Readonly = "I have the power"
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Game - Display to (All players) the text: (ReadonlyVar)
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-------- The above will STILL display "static" --------
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-
Lua:
if Debug then Debug.beginFile 'GlobalRemap' end
--[[
Global Variable Remapper v1.4 by Bribe
Turns normal GUI variables into function calls that integrate seamlessly with Lua.
--]]
local oldInit = InitGlobals
function InitGlobals()
oldInit()
local printError = Debug and Debug.throwError or print
---@param name string
---@param error string
local function softErrorHandler(name, error)
printError('!!!GlobalRemap Error!!! "' .. name .. '" ' .. error)
end
if not Hook then --https://github.com/BribeFromTheHive/Lua/blob/master/Hook.lua
softErrorHandler('Hook', 'is required but not found.')
return
end
local default = DoNothing
local getters = {}
local setters = {}
---@param hook Hook.property
---@param _G table
---@param key string
---@return unknown
local function __index(hook, _G, key)
if getters[key]~=nil then
return getters[key]()
end
return hook.next(_G, key)
end
---@param hook Hook.property
---@param _G table
---@param key string
---@param val unknown
local function __newindex(hook, _G, key, val)
if setters[key]~=nil then
setters[key](val)
else
hook.next(_G, key, val)
end
end
Hook.add('__index', __index, 0, _G, rawget)
Hook.add('__newindex', __newindex, 0, _G, rawset)
---Remap a global variable (non-array) to call getFunc when referenced or setFunc when assigned.
---This serves as a permanent hook and cannot be removed.
--
---@param variableStr string # a string such as "udg_MyVariable"
---@param getFunc? fun(): unknown # a function that takes nothing but returns the expected value when `udg_MyVariable` is referenced.
---@param setFunc? fun(value: unknown) # a function that takes a single argument (the value that is being assigned) and allows you to do what you want when someone uses `Set MyVariable = SomeValue`. The function doesn't need to do anything nor return anything, so it even allows read-only GUI variables.
function GlobalRemap(variableStr, getFunc, setFunc)
if getters[variableStr] then
softErrorHandler(variableStr, 'has been remapped twice. There can only be one remap per variable.')
return
end
_G[variableStr] = nil --Delete the variable from the global table.
getters[variableStr] = getFunc or default --Assign a function that returns what should be returned when this variable is referenced.
setters[variableStr] = setFunc or default --Assign a function that captures the value the variable is attempting to be set to.
end
---This function allows you to override the behavior of a global array variable.
---
---You can provide custom getter and setter functions that will be called whenever the variable is accessed or modified.
---
---If 'preserveState' is 'true', the original array is preserved and passed to the getter and setter functions as an extra parameter.
---This is particularly useful when multiple resources want to remap the same array. As long as the resource that called it
---most recently handles the previous state correctly, multiple remappings can coexist without conflict.
---
---Like GlobalRemap, this hook cannot be reversed.
---
---@param variableStr string # The name of the global array variable you want to remap, such as "udg_MyVariableArray".
---@param getFunc fun(index: unknown, state?: table): unknown # A function that takes the index of the array and a table representing the current state of the variable.
---@param setFunc? fun(index: unknown, value: unknown, state?: table) # A function that takes the index of the array, the value that is being assigned to the variable, and a table representing the current state of the variable.
---@param preserveState? true # If not provided, the state passed to the callback functions will simply be 'nil'
function GlobalRemapArray(variableStr, getFunc, setFunc, preserveState)
getFunc = getFunc or default
setFunc = setFunc or default
local state = _G[variableStr]
if type(state) ~= 'table' then
softErrorHandler(variableStr, 'is an invalid array to remap. Its type must be "table" but is instead "' .. type(state) .. '".')
return
end
state = preserveState and state
_G[variableStr] = setmetatable({}, {
__index = function(_, index)
return getFunc(index, state)
end,
__newindex = function(_, index, val)
setFunc(index, val, state)
end
})
end
end
if Debug then Debug.endFile() endChanges from previous version
Unit Tests (can be run in ZeroBrane Studio)
Last edited:
