lua/lua/gmod_integration/shared/sh_player_meta.lua

//
// Meta
//

local ply = FindMetaTable("Player")

function ply:gmIntGetConnectTime()
    return self.gmIntTimeConnect || 0
end

function ply:gmIntSetCustomValue(key, value)
    self.gmIntCustomValues = self.gmIntCustomValues || {}
    self.gmIntCustomValues[key] = value
end

function ply:gmIntGetCustomValue(key)
    return self.gmIntCustomValues && self.gmIntCustomValues[key]
end

function ply:gmIntRemoveCustomValue(key)
    if (self.gmIntCustomValues) then
        self.gmIntCustomValues[key] = nil
    end
end

//
// Compatibility
//

local function getCustomCompatability(ply)
    local values = {}

    // DarkRP
    if (DarkRP) then
        values.money = ply:getDarkRPVar("money")
        values.job = ply:getDarkRPVar("job")
    end

    // GUI Level System
    if (GUILevelSystem) then
        values.level = ply:GetLevel()
        values.xp = ply:GetXP()
    end

    return values
end

//
// Methods
//

local function getCustomValues(ply)
    local values = {}

    // Get compatability values
    for key, value in pairs(getCustomCompatability(ply)) do
        values[key] = value
    end

    // Get custom values or overwrite compatability values
    if (ply.gmIntCustomValues) then
        for key, value in pairs(ply.gmIntCustomValues) do
            values[key] = value
        end
    end

    return values
end

function ply:gmIntGetCustomValues()
    return getCustomValues(self)
end