Whitelist

This example implements a simple whitelist without a separate database. It uses mc.data for persistence, a typed player command argument, and the cancellable player.login event.

Save this as config/ignis/whitelist.lua:

mc.data.whitelist = mc.data.whitelist or {}
local whitelist = mc.data.whitelist

mc.on("player.login", function(e)
    -- Keep operators able to join while setting up the whitelist.
    if e.player.isOp then
        return
    end

    if not whitelist[e.player.uuid] then
        e:cancel("You are not whitelisted on this server")
    end
end, { priority = "highest" })

register("px whitelist add <target:player>", function(ctx, target)
    whitelist[target.uuid] = {
        name = target.name,
        addedAt = mc.time()
    }

    ctx.player:sendMessage("Added " .. target.name .. " to the whitelist.")
end, "px.whitelist")

local function removeEntry(ctx, uuid, name)
    if not whitelist[uuid] then
        ctx.player:sendMessage("Player not found in the whitelist: " .. name)
        return
    end

    whitelist[uuid] = nil
    ctx.player:sendMessage("Removed " .. name .. " from the whitelist.")
end

register("px whitelist remove <target:player>", function(ctx, target)
    removeEntry(ctx, target.uuid, target.name)
end, "px.whitelist")

register("px whitelist remove <target:word>", function(ctx, target)
    -- The word form also works for players who are offline.
    local query = target:lower()

    if whitelist[target] then
        removeEntry(ctx, target, target)
        return
    end

    for uuid, entry in pairs(whitelist) do
        if entry.name:lower() == query then
            removeEntry(ctx, uuid, entry.name)
            return
        end
    end

    removeEntry(ctx, target, target)
end, "px.whitelist")

register("px whitelist list", function(ctx)
    local count = 0

    for _, entry in pairs(whitelist) do
        count = count + 1
        ctx.player:sendMessage(entry.name)
    end

    ctx.player:sendMessage("Whitelist entries: " .. count)
end, "px.whitelist")

Usage

The commands require the px.whitelist permission:

/px whitelist add <online player>
/px whitelist remove <online player>
/px whitelist remove <offline name or UUID>
/px whitelist list

The player argument resolves an online player and supplies a stable UUID. The UUID is used as the storage key, while the player name is kept for display.

The built-in /whitelist command is reserved by Minecraft, so this example uses the /px whitelist command path instead.

Notes

• The whitelist starts empty, so operators can join and add players.
• Non-whitelisted players are rejected during player.login, before the normal join event.
• If the handler fails with an error, the login is refused as well (cancellable events fail closed), so a bug does not let everyone in.
• Entries survive /ignis reload and server restarts through mc.data.
• The player form removes an online player by UUID.
• The word form removes an offline player by their saved name or UUID.

See also registering commands, events, and persistent storage.