LocalPlayer() is null?

[feavyr]

https://i.imgur.com/oWgWwlT.png

So I get the error above, and I can't find out why... Here's the code it's referring to:
local function comma_value(amount)
    local formatted = amount

    while true do  
        formatted, k = string.gsub(formatted, "^(-?%d+)(%d%d%d)", '%1,%2')

        if (k == 0) then
            break
        end
    end

    return formatted
end

local ply = LocalPlayer()

-- Main Rectangle
local mainRect = vgui.Create("DPanel")
mainRect:SetSize(ScrW(), 20) -- Set the size of the panel
mainRect:DockPadding(5, 5, 5, 5)
mainRect:SetBackgroundColor(Color(50, 50, 50, 255))

local Health = math.Clamp(ply:Health(), 0, 100)
local HealthText = "Health: " .. tostring(Health) .. "%"
mainRect.HealthLabel = mainRect:Add("DLabel")
mainRect.HealthLabel:SetDark(false)
mainRect.HealthLabel:Dock(TOP)

mainRect:Hide()

function mainRect:Think()
    self.HealthLabel:SetText(("Health: %d"):format(LocalPlayer():Health()))
    --self.ArmorLabel:SetText(("Armor: %d"):format(LocalPlayer():Armor()))
end

hook.Add("HUDPaint", "Custom_Hud_DarkRP", function()
    mainRect:PaintAt(0, 0)
end)
Now, at first I thought, "this must be because the LocalPlayer() isn't loaded at the time of the script running, right?"... Welp, for one that wouldn't make sense, as it's a module that's loaded with DarkRP, so the gamemode must be initialized before this script runs... And two, just to try it, I tried putting this all in GM:Initialize(), but it didn't work. I literally have no idea wtf is going on lol.

[BigCoderGmod]

Perhaps check if LocalPlayer() is valid?

[Kevlon]

Yes localplayer isn't valid when the script is loaded and vgui isn't either since the player hasn't loaded in yet

[feavyr]

Tried checking, but I just get no results. So I assume I need to check each frame. So I also tried checking in the HUDPaint and Think... Then I get errors...
Code:
if LocalPlayer():IsValid() then
    local ply = LocalPlayer()
    local Health = math.Clamp(ply:Health(), 0, 100)
    local Armor = math.Clamp(ply:Armor(), 0, 100)
    local Money = comma_value(ply:getDarkRPVar("money"))
    local Salary = comma_value(ply:getDarkRPVar("salary"))
    local Job = ply:getDarkRPVar("job")

    -- Main Rectangle
    local mainRect = vgui.Create("DPanel")
    mainRect:SetSize(ScrW(), 20)
    mainRect:DockPadding(5, 5, 5, 5)
    mainRect:SetBackgroundColor(Color(50, 50, 50, 255))

    mainRect.HealthLabel = mainRect:Add("DLabel")
    mainRect.HealthLabel:Dock(TOP)

    mainRect:Hide()
end

function mainRect:Think()
    if LocalPlayer():IsValid() then
        self.HealthLabel:SetText(("Health: %d"):format(Health))
        --self.ArmorLabel:SetText(("Armor: %d"):format(LocalPlayer():Armor()))
    end
end

hook.Add("HUDPaint", "Custom_Hud_DarkRP", function()
    if LocalPlayer():IsValid() then
        mainRect:PaintAt(0, 0)
    end
end)
Error:
[ERROR] addons/darkrpmodification/lua/darkrp_modules/hudreplacement/cl_hudreplacement.lua:76: attempt to index global 'mainRect' (a nil value)
  1. unknown - addons/darkrpmodification/lua/darkrp_modules/hudreplacement/cl_hudreplacement.lua:76
   2. doInclude - [C]:-1
    3. loadModules - gamemodes/darkrp/gamemode/libraries/modificationloader.lua:102
     4. Call - gamemodes/darkrp/gamemode/libraries/modificationloader.lua:147
      5. unknown - gamemodes/darkrp/gamemode/cl_init.lua:56

[posix_t9]

Could just delay until after InitPostEntity

[stealthpaw]

You seem to be misunderstanding how lua files are read and now hooks work. This is should work:
local function comma_value(amount)
local formatted = amount
while true do  
formatted, k = string.gsub(formatted, "^(-?%d+)(%d%d%d)", '%1,%2')
if (k == 0) then
break
end
end
return formatted
end

-- Main Rectangle
local mainRect = vgui.Create("DPanel")
mainRect:SetSize(ScrW(), 20)
mainRect:DockPadding(5, 5, 5, 5)
mainRect:SetBackgroundColor(Color(50, 50, 50, 255))

mainRect.HealthLabel = mainRect:Add("DLabel")
mainRect.HealthLabel:Dock(TOP)

mainRect:Hide()

function mainRect:Think()
    local ply = LocalPlayer()
if !IsValid(ply) then return end
local Health = math.Clamp(ply:Health(), 0, 100)
    local Armor = math.Clamp(ply:Armor(), 0, 100)
    local Money = comma_value(ply:getDarkRPVar("money"))
    local Salary = comma_value(ply:getDarkRPVar("salary"))
    local Job = ply:getDarkRPVar("job")
self.HealthLabel:SetText(("Health: %d"):format(Health))
--self.ArmorLabel:SetText(("Armor: %d"):format(LocalPlayer():Armor()))
end

hook.Add("HUDPaint", "Custom_Hud_DarkRP", function()
mainRect:PaintAt(0, 0)
end)

[c👌de_g🎷]

LocalPlayer will never return a non-entity - it is safe to use obj:IsValid() in that case.