Your Second Lua Plugin

The Golden Snitch Detector

Let’s build a plugin that monitors all Lua code being loaded on the server and alerts you when it contains the text “the golden snitch”.

This introduces event handling with Autorun.on() and the powerful loadbuffer event.

Setup

Create your plugin structure:

• Directorysnitch_detector

  • Directorysrc

    • Directoryclient

      • init.lua
  • plugin.toml

plugin.toml

[plugin]
name = "snitch_detector"
author = "you"
version = "0.1.0"
description = "Detects the golden snitch in loaded code"
language = "lua"

The loadbuffer Event

The loadbuffer event fires whenever Lua code is about to be loaded and executed. This includes addon code, console commands, RunString calls - everything.

See the Events reference for full parameter details.

Implementation

client/init.lua

Autorun.on("loadbuffer", function(name, content, mode)
    if string.find(content, "the golden snitch") then
        Autorun.print("Found the golden snitch in: " .. name)
    end
end)

That’s it. The event handler receives every piece of code loaded on the server and checks if it contains our target string.

Going Further

Counting Occurrences

local snitchCount = 0

Autorun.on("loadbuffer", function(name, content, mode)
    if string.find(content, "the golden snitch") then
        snitchCount = snitchCount + 1
        Autorun.print("Snitch #" .. snitchCount .. " found in: " .. name)
    end
end)

Logging to File

Autorun.on("loadbuffer", function(name, content, mode)
    if string.find(content, "the golden snitch") then
        local timestamp = os.date("%Y-%m-%d %H:%M:%S")
        local log = string.format("[%s] Found in: %s\n", timestamp, name)

        -- Append to log file
        Autorun.append("snitches.txt", log)

        Autorun.print("Logged snitch detection: " .. name)
    end
end)

Note

Autorun.write() is restricted to your plugin’s /data/ directory for security. The file will be at autorun/plugins/snitch_detector/data/snitches.txt.

Performance Considerations

The loadbuffer event fires frequently. Keep your handlers fast:

Bad

Autorun.on("loadbuffer", function(name, content, mode)
    -- Don't do expensive operations on every single chunk
    for i = 1, 1000000 do
        -- Heavy processing
    end
end)

Good

Autorun.on("loadbuffer", function(name, content, mode)
    -- Quick string check, bail early if no match
    if not string.find(content, "the golden snitch") then
        return
    end

    -- Only do work when needed
    Autorun.print("Found snitch in: " .. name)
end)