[feature] Being Able To Export Metatables

5m1Ly · 2023-02-21T14:27:54.151Z

I created this post in addition to this bug report.

[lua] auto reset of metamethods when exporting table Bug reports

The problem Like many of us know we can create exports for a resource and call these within an other resource. This way you can easly share functionallity across resources without having to rewrite logic. This is very usefull in many cases, there is only one problem i’m constantly figthing with, this is exporting the metamethods of a table in lua. Metatables in lua are tables that contain a set of functionallity (also called metamethods), which are used to define the opperational logic of a tab…

Current State

So as shown in the bug report that i made a while back. I’ts not possible to export a MetaTable, according to d-bubble this is because MetaTables don’t exist in JavaScript and C#, just like Classes that don’t exist in Lua.

Feature Request

So this topic was created to ask if it would be possible to do a language check, meaning that if you export a MetaTable in a Lua file and that call this export in the Lua file that the MetaTable remains and otherwise it becomes an Array or Object Notation.

xander1998 · 2023-02-21T15:05:24.072Z

I have a small workaround for this. If you load the class as a script you can set the data sent over the export and add the meta tables back on the data after it is passed.

copas_zzz · 2024-08-26T13:09:57.852Z

local function refresh(self)
    local object = {}
    for k, v in pairs(self) do
        object[k] = v
    end
    for k, v in pairs(Events) do
        if type(v) == "function" and not object[k] then
            object[k] = function(...)
                return v(self, ...)
            end
        end
    end
    setmetatable(object, Events)
    return object
end

this worked for me, after which I was able to use it normally, but I don’t think it’s a good approach

I realized that when it comes to transferring this information, it is lost only as a table, but if I use getmetatable, it goes only with the methods, using the above approach worked, but it doesn’t seem good to me

copas_zzz · 2024-08-26T20:15:11.203Z

analyzing it a little further, I realized that when using the code above, this was happening:

__cfx_functionReference: rvn:491:28

which leads me to believe that it is referencing the methods and not creating copies, which in my mind leads me to believe that there would be no problems, I am analyzing the code available on github to see if I find anything else

the method below helped me, it’s the fivem standard:

function Citizen.GetFunctionReference(func)
    if type(func) == 'function' then
        return MakeFunctionReference(func)
    elseif type(func) == 'table' and rawget(func, '__cfx_functionReference') then
        return MakeFunctionReference(function(...)
            return func(...)
        end)
    end

    return nil
end