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Server Scripting Reference

Server Version 3.X

Introduction

BeamMP-Server release v3.0.0 does some drastic changes to the way the Lua plugin system works. There is no way to use the old lua with a new server, so you'll have to migrate.

The Server's Plugin system uses Lua 5.3. This section details how to get started writing plugins, teaches some basic concepts and gets you started with your first plugin. It is recommended you read this section even if you know the pre-v3.0.0 system, as a few things changed drastically.

For a migration guide from pre-v3.0.0 lua, go to the section "Migrating from old Lua".

Directory Structure

Server plugins, unlike mods, are situated (by default) in Resources/Server, while mods, which are written for BeamNG.drive and are sent to the clients are in Resources/Client. Each plugin must have it's own subfolder in Resources/Server, for example for a plugin called "MyPlugin", the structure would be:

Resources
└── Server
    ├── MyPlugin
    │   └── main.lua
    └── SomeOtherPlugin
        └── ...

Here we also display another plugin called "SomeOtherPlugin", to illustrate how your Resources/Server folder can have multiple different plugin folders. We will keep using this directory structure as an example throughout this guide.

You also notice the main.lua. You can have as many Lua .lua files as you like. All Lua files in your plugin's main directory are loaded in alphabetical order (so aaa.lua is run before bbb.lua).

Lua Files

Each Lua .lua file in the plugin's folder is loaded on server startup. This means that statements outside of functions are evaluated ("run") immediately.

Lua files in subfolders are ignored, but can be require()-ed.

For example, our main.lua looks like this:

function PrintMyName()
    print("I'm 'My Plugin'!")
end

print("What's up!")

When the server starts and the main.lua is loaded, it will run print("What's up!") immediately, but will NOT call the PrintMyName function yet (because it wasn't called)!

Events

An event is something like "a player is joining", "a player sent a chat message", "a player spawned a vehicle".

You can cancel events (if they are cancellable) by returning 1 from the handler.

In Lua, you usually want to react to some of these. For this, you can register a "Handler". This is a function which is called when an event happens, and gets passed some arguments.

Example:

function MyChatMessageHandler(sender_id, sender_name, message)
    -- censoring only the exact message 'darn'
    if message == "darn" then
        -- cancel the event by returning 1
        return 1
    else
        return 0
    end
end

MP.RegisterEvent("onChatMessage", "MyChatMessageHandler")

This will effectively make sure that any message that is exactly equal to "darn" will not be sent and won't show in chat (note that for a real profanity filter you'd want to see if the message contains "darn", not is "darn"). Cancelling an event causes it to not happen, for example a chat message not to be shown to anyone else, a vehicle not to be spawned, etc.

Custom Events

You can register to any event you like, for example:

MP.RegisterEvent("MyCoolCustomEvent", "MyHandler")

You can then trigger those custom events:

-- call all event handlers to this in ALL plugins
MP.TriggerGlobalEvent("MyCoolCustomEvent")
-- call all event handlers to this in THIS plugin
MP.TriggerLocalEvent("MyCoolCustomEvent")

You can do a lot more with events, but those possibilities will be covered in detail below in the API reference.

Event Timers ("Threads")

Pre-v3.0.0 Lua had a concept of "threads" which run X times per second. This naming was slightly misleading, as they were synchronous.

v3.0.0 Lua instead has "Event Timers". These are timers which run inside the server, and once they run out, they trigger an event (globally). This is also synchronous. Please be aware that the second argument is an interval in milliseconds.

Example:

local seconds = 0

function CountSeconds()
    seconds = seconds + 1
end

-- create a custom event called 'EverySecond'
-- and register the handler function 'CountSeconds' to it
MP.RegisterEvent("EverySecond", "CountSeconds")

-- create a timer for this event, which will fire every 1000ms (1s)
MP.CreateEventTimer("EverySecond", 1000)

This will cause "CountSeconds" to be called every second. You can also cancel event timers with MP.CancelEventTimer (see API reference).

From the server's console, you can run status to see how many event timers are currently running, as well as info about event handlers that are waiting. This command will show more information in the future.

Debugging

Lua is difficult to debug. An industry-grade debugger like gdb sadly doesn't exist for embedded Lua.

Generally, you can of course simple print() the values you want to inspect at any time.

In v3.0.0, the server provides a way for you to inject an interpreter into a plugin and subsequently run Lua inside it in realtime. This is the closest we have to a debugger.

Assuming you have the plugin from above which we called MyPlugin, you can enter into its Lua state like so:

> lua MyPlugin

Capitalisation matters here, so be careful its entered correctly. The output is something like

lua @MyPlugin> 
As you can see, we switched into the Lua state for MyPlugin. From now on until we enter exit() (as of v3.1.0 :exit), we will be in MyPlugin and can execute Lua there.

For example, if we have a global called MyValue, we can print that value like so:

lua @MyPlugin> print(MyValue)

You can call functions here and do anything you expect to be able to do.

Since v3.1.0: You can press TAB to autocomplete functions and variables.

WARNING: Sadly, if the Lua state is currently busy executing other code (like a while loop), this can fully hang the console until it finishes that work, so be very careful switching to states which may be waiting for something to happen.

Additionally, you can run status in the regular console (>), which will show you some statistics about Lua, among other things.

Custom Commands

In order to implement custom commands for the server console, the event onConsoleInput can be used. This can be useful when you want to add a way for the server owner to signal something to your plugin, or to display internal state in a custom way.

Here's an example:

function handleConsoleInput(cmd)
    local delim = cmd:find(' ')
    if delim then
        local message = cmd:sub(delim+1)
        if cmd:sub(1, delim-1) == "print" then
            return message
        end
    end
end

MP.RegisterEvent("onConsoleInput", "handleConsoleInput")

This will enable you to do the following in the server's console:

> print hello, world
hello, world

We implemented our own print. As an exercise, try to build a function like say, which sends a chat message to all players, or even a specific player (with MP.SendChatMessage).

Caution: For your own plugins, it's generally recommended to "namespace" them. Our print example, in a plugin called mystuff, could be called mystuff.print or ms.print or similar.

API Reference

Documentation format: function_name(arg_name: arg_type, arg_name: arg_type) -> return_types

Builtin Functions

Prints the message to the server console, prefixed with [DATE TIME] [LUA]. If you don't want this prefix, you can use printRaw(...).

Example:

local name = "John Doe"
print("Hello, I'm", name, "and I'm", 32)

It can take as many arguments of arbitrary types as you like. It will also happily dump tables!

This behaves like the lua interpreter's print, so it will put tabs between arguments.

exit()

Shuts down the server gracefully. Causes the onShutdown event to be triggered.

MP Functions

MP.CreateTimer() -> Timer

Creates a timer object, which can be used to keep track of how long something took / how much time elapsed. It starts once created, and can be reset/restarted with mytimer:Start().

You can get the current elapsed time in seconds with mytimer:GetCurrent().

Example:

local mytimer = MP.CreateTimer()
-- do stuff here that needs to be timed
print(mytimer:GetCurrent()) -- print how much time elapsed

Timers do not need to be stopped (and can't be stopped), they have no overhead.

MP.GetOSName() -> string

Returns the name of the current OS, either Windows, Linux or Other.

MP.GetServerVersion() -> number,number,number

Returns the current server version in major, minor, patch format. For example, the v3.0.0 version would return 3, 0, 0.

Example:

local major, minor, patch = MP.GetServerVersion()
print(major, minor, patch)
Output:
2   4   0

MP.RegisterEvent(event_name: string, function_name: string)

Remembers the function with name Function Name as an event handler to event with name Event Name.

You can register as many handlers to an event as you like.

For a list of events the server provides, see here.

If the event with that name doesn't exist, it's created, and thus RegisterEvent cannot fail. This can be used to create custom events.

MP.CreateEventTimer(event_name: string, interval_ms: number, [strategy: number (since v3.0.2)])

Starts a timer inside the server which triggers the event event_name every interval_ms milliseconds.

Event timers can be cancelled with MP.CancelEventTimer.

Intervals <25 ms are not encouraged, as multiple such intervals will likely not be served in time reliably. While multiple timers can be started on the same event, it's encouraged to create as few event timers as possible. For example, if you need one event that runs every half second, and one which runs every second, consider just making the half-second one and running the every-second-functiosecond trigger.

You may also use MP.CreateTimer to make a timer and measure time passed since the last event call, in order to minimize event timers, though this is not necessarily recommended as it increases the code complexity significantly.

Since 3.0.2:

An optional CallStrategy may be supplied as the third argument. This can be either:

  • MP.CallStrategy.BestEffort (default): Will try to get your event to trigger at the specified interval, but will refuse to queue handlers if a handler takes too long.
  • MP.CallStrategy.Precise: Will enqueue event handlers at the exact interval specified. Can lead to the queue filling up if the handler takes longer than the interval. Only use if you NEED the exact interval.

MP.CancelEventTimer(event_name: string)

Cancels all timers on the event with the name event_name On some occasions, the timer might go off one more time before being cancelled, due to the nature of asynchronous programming.

MP.TriggerLocalEvent(event_name: string, ...) -> table

Plugin-local synchronous event trigger.

Triggers an event locally, which causes all handlers to that event in the current lua state (usually the current plugin, unless state was shared via PluginConfig.toml) to be called.

You can pass arguments to this function (...) which are copied and sent to all handlers as function arguments.

This call is synchronous and will return once all event handlers finished.

The returned value is a table of all results. If a handler returned a value, it will be in this table, unannotated and unnamed. This can be used to "collect" things, or register sub-handlers for events that can be cancelled. This is practically an array.

Example:

local Results = MP.TriggerLocalEvent("MyEvent")
print(Results)

MP.TriggerGlobalEvent(event_name: string, ...) -> table

Global asynchronous event trigger.

Triggers an event globally, which causes all handlers to that event in all plugins (including this plugin) to be called.

You can pass arguments to this function (...) which are copied and sent to all handlers as function arguments.

This call is asynchronous and returns a future-like object. Local handlers (handlers in the same plugin as the caller) run synchronously and immediately.

The table returned has two functions:

  • IsDone() -> boolean tells you whether all handlers have finished. You can wait until this is true by checking it and MP.Sleep-ing for a little bit in a loop.
  • GetResults() -> table returns an unannotated unnamed table with all return values of all handlers. This is practically an array.

Make sure to call these with Obj:Function() syntax (:, NOT .).

Example:

local Future = MP.TriggerGlobalEvent("MyEvent")
-- wait until handlers finished
while not Future:IsDone() do
    MP.Sleep(100) -- sleep 100 ms
end
local Results = Future:GetResults()
print(Results)

Be aware that a handler registering to "MyEvent" here and never returning could lock up your plugin. You likely want to keep track of how long you have waited and stop waiting after a few seconds.

MP.Sleep(time_ms: number)

Waits for an amount of time, specified in milliseconds.

This does not yield the execution of the lua state and nothing will execute in the state while asleep.

WARNING: Do NOT sleep for >500 ms if you have event handlers registered, unless you know exactly what you are doing. This is intended to be used to sleep for 1-100 ms, in order to wait for results or similar. A locked up (sleeping) lua state can slow the entire server down drastically if not careful.

MP.SendChatMessage(player_id: number, message: string)

Sends a chat message that only the specified player can see (or everyone if the ID is -1). In the game, this will not appear as a directed message.

You can use this, for example, to tell a player why you cancelled their vehicle spawn, chat message, or similar, or to display some information about your server.

MP.TriggerClientEvent(player_id: number, event_name: string, data: string) -> boolean

until v3.1.0

MP.TriggerClientEvent(player_id: number, event_name: string, data: string) -> boolean,string

since v3.1.0

MP.TriggerClientEventJson(player_id: number, event_name: string, data: table) -> boolean,string

since v3.1.0

Will call the given event with the given data on the specified client (-1 for broadcast). This event can then be handled in a clientside lua mod, see the "Client Scripting" documentation for this.

Will return true if it was able to send the message (for id = -1, so broadcasts, its always true), and false if the player with that ID doesn't exist or is disconnected but still has an ID (this is a known issue).

If false is returned, it makes no sense to retry this event, and a response (if any was expected) shouldn't be expected.

Since v3.1.0, the second return value contains an error message if the function failed. Also since this version, the *Json version of the function takes a table as the data argument, and converts it to json. This is simply a shorthand for MP.TriggerClientEvent(..., Util.JsonEncode(mytable)).

MP.GetPlayerCount() -> number

Returns the amount of players currently in the server.

MP.GetPositionRaw(pid: number, vid: number) -> table,string

Returns the current position of the vehicle vid (vehicle id) of player pid (player id), and an error string if an error occurred.

The table is decoded from a position packet, so it has a variety of data (that's why this function is postfixed "Raw").

TODO: Document fields. For now, users need to print() the result.

MP.IsPlayerConnected(player_id: number) -> boolean

// TODO Documentation incomplete

Whether the player is connected.

MP.GetPlayerName(player_id: number) -> string

Gets the display-name of the player.

MP.RemoveVehicle(player_id: number, vehicle_id: number)

Removes the specified vehicle for the specified player.

MP.GetPlayerVehicles(player_id: number) -> table

Returns a table of all vehicles the player currently has. Each entry in the table is a mapping from vehicle ID to vehicle data (which is currently a raw json string).

MP.GetPlayers() -> table

Returns a table of all connected players. This table maps IDs to Names, like so:

{
    0: "LionKor",
    1: "JohnDoe"
}

MP.IsPlayerGuest(player_id: number) -> boolean

Whether the player is a guest. A guest is someone who didn't log in, and instead chose to play as a guest. Their name is usually guest followed by a long number.

As guests aren't logged in, you might want to disallow them from joining, for example when running a serious racing server or similar.

MP.DropPlayer(player_id: number, [reason: string])

Kicks the player with the specified ID. The reason parameter is optional.

MP.GetStateMemoryUsage() -> number

Returns the memory usage of the current Lua state in bytes.

MP.GetLuaMemoryUsage() -> number

Returns the memory usage of all lua states combined, in bytes.

MP.GetPlayerIdentifiers(player_id: number) -> table

Returns a table with information about the player, such as beammp forum ID and IP address.

Example:

{
    ip: "1.2.3.4",
    beammp: "1234"
}

Until v3.1.0 the ip field is incorrect and will not work as intended. Fixed in v3.1.0.

MP.Set(setting: number, ...)

Sets a ServerConfig setting temporarily. For this, the MP.Settings table is useful.

Example:

Turning on Debug mode

MP.Set(MP.Settings.Debug, true)

MP.Settings

You can see an up-to-date list of these by printing them, like so:

print(MP.Settings)

Util Functions

Util.Json*

Since BeamMP-Server v3.1.0.

This is a builtin JSON library, which is usually much faster than any Lua JSON library. Behind the scenes, C++'s nlohmann::json library is used, which is JSON compliant, full-coverage unit tested and continuously being fuzzed.

Util.JsonEncode(table: table) -> string

Encodes a Lua table into a JSON string, recursively (tables inside tables inside tables ... work as expected). All primitive types are respected, functions, userdata and similar are ignored.

The resulting JSON is minified and can be pretty-printed by using Util.JsonPrettify to prettify it.

Example:

local player = {
    name = "Lion",
    age = 69,
    skills = { "skill A", "skill B" }
}
local json = Util.JsonEncode(player)

Results in:

{"name":"Lion","age":69,"skills":["skill A","skill B"]}

Util.JsonDecode(json: string) -> table

Decodes JSON into a Lua table. Will return nil if this failed, and print an error.

Example:

local json = "{\"message\":\"OK\",\"code\":200}"
local tbl = Util.JsonDecode(json)

Results in:

{
    message = "OK",
    code = 200,
}

Util.JsonPrettify(json: string) -> string

Add indentation and newlines to the json to make it more readable for humans.

Example:

local myjson = Util.JsonEncode({ name="Lion", age = 69, skills = { "skill A", "skill B" } })

print(Util.JsonPrettify(myjson))

Results in:

{
    "age": 69.0,
    "name": "Lion",
    "skills": [
        "skill A",
        "skill B"
    ]
}

Util.JsonMinify(json: string) -> string

Removes indentation, newlines and any other whitespace. Not necessary unless you called Util.JsonPrettify, as all output from Util.Json* is already minified.

Example:

local pretty = Util.JsonPrettify(Util.JsonEncode({ name="Lion", age = 69, skills = { "skill A", "skill B" } }))

print(Util.JsonMinify(pretty))

Results in:

{"age":69.0,"name":"Lion","skills":["skill A","skill B"]}

Util.JsonFlatten(json: string) -> string

Creates a JSON object whose key are flattened to JSON pointers, according to RFC 6901. You can restore the original with Util.JsonUnflatten(). For this to work, all values need to be primitives.

Example:

local json = Util.JsonEncode({ name="Lion", age = 69, skills = { "skill A", "skill B" } })
print("normal: " ..json)
print("flattened: " .. Util.JsonFlatten(json))
print("flattened pretty: " .. Util.JsonPrettify(Util.JsonFlatten(json)))

Results in:

normal: {"age":69.0,"name":"Lion","skills":["skill A","skill B"]}
flattened: {"/age":69.0,"/name":"Lion","/skills/0":"skill A","/skills/1":"skill B"}
flattened pretty: {
    "/age": 69.0,
    "/name": "Lion",
    "/skills/0": "skill A",
    "/skills/1": "skill B"
}

Util.JsonUnflatten(json: string) -> string

Restores the arbitrary nesting of a JSON value that has been flattened before using the Util.JsonFlatten() function.

Util.JsonDiff(a: string, b: string) -> string

Creates a JSON diff according to RFC 6902 (http://jsonpatch.com/). This diff can then be applied as a patch via Util.JsonDiffApply(). Returns the diff.

Util.JsonDiffApply(base: string, diff: string) -> string

Applies the JSON diff to base as a JSON patch (RFC 6902, http://jsonpatch.com/). Returns the result.

Util.Random*

Since BeamMP-Server v3.1.0.

Util.Random() -> float

Returns a float between 0 and 1.

Example:

local rand = Util.Random()
print("rand: " .. rand)

Results in:

rand: 0.135477

Util.RandomIntRange(min: int, max: int) -> int

Returns an integer between min and max.

Example:

local randInt = Util.RandomIntRange(1, 100)
print("randInt: " .. randInt)

Results in:

randInt:  69

Util.RandomRange(min: number, max: number) -> float

Returns a float between min and max.

Example:

local randFloat = Util.RandomRange(1, 1000)
print("randFloat: " .. randFloat)

Results in:

randFloat: 420.6969

Util.LogInfo(params: ...) et al (since v3.3.0)

Util.LogInfo("Hello, World!")
Util.LogWarn("Cool warning")
Util.LogError("Oh no!")
Util.LogDebug("hi")
produces

[19/04/24 11:06:50.142] [Test] [INFO] Hello, World!    
[19/04/24 11:06:50.142] [Test] [WARN] Cool warning    
[19/04/24 11:06:50.142] [Test] [ERROR] Oh no!
[19/04/24 11:06:50.142] [Test] [DEBUG] hi

Supports the exact same printing / dumping of data as print() does.

Util.DebugExecutionTime() -> table

When Lua code runs in the server, each event handler's execution is timed. The min, max, average (mean) and standard deviation of these execution times are calculated, and are returned in a table by this function. The calculation takes place incrementally, so every time an event handler runs the min, max, average and standard deviation are updated. This way, Util.DebugExecutionTime() does not usually take any significant amount of time to execute (sub 0.25ms).

It returns a table like this:

[[table: 0x7af6d400aca0]]: {
    printStuff: [[table: 0x7af6d400be60]]: {
        mean: 0.250433,
        n: 76,
        max: 0.074475,
        stdev: 0.109405,
        min: 0.449274,
    },
    onInit: [[table: 0x7af6d400b130]]: {
        mean: 0.033095,
        n: 1,
        max: 0.033095,
        stdev: 0,
        min: 0.033095,
    },
}   
Per event handler, returns the following data:

  • n: Amount of times the event triggered and a handler was called
  • mean: Average/mean of all execution times, in ms
  • max: The longest execution time, in ms
  • min: The shortest execution time, in ms
  • stdev: The standard deviation of all execution time averages, in ms

Here's a function you can use to pretty-print this data:

function printDebugExecutionTime()
    local stats = Util.DebugExecutionTime()
    local pretty = "DebugExecutionTime:\n"
    local longest = 0
    for name, t in pairs(stats) do
        if #name > longest then
            longest = #name
        end
    end
    for name, t in pairs(stats) do
        pretty = pretty .. string.format("%" .. longest + 1 .. "s: %12f +/- %12f (min: %12f, max: %12f) (called %d time(s))\n", name, t.mean, t.stdev, t.min, t.max, t.n)
    end
    print(pretty)
end

You may call it like this to debug your code if it's slow:

-- event to print the debug times
MP.RegisterEvent("printStuff", "printDebugExecutionTime")
-- run every 5000 ms = 5 seconds (or 10, or 60, whatever makes sense for you
MP.CreateEventTimer("printStuff", 5000)

FS Functions

FS functions are filesystem functions, which aim to be better than the default Lua capabilities.

Please always use / as a separator when specifying paths, as this is cross-platform (windows, linux, macos, ...).

FS.CreateDirectory(path: string) -> bool,string

Creates the specified directory, and any parent directories if they don't exist. Behavior is roughly equivalent to the common linux command mkdir -p.

Returns whether the operation had an error, and, if it did, an error message. This means that, if true is returned, an error occurred.

Example:

local error, error_message = FS.CreateDirectory("data/mystuff/somefolder")

if error then
    print("failed to create directory: " .. error_message)
else
    -- do something with the directory
end

FS.Remove(path: string) -> bool,string

Removes the specified file or folder.

Returns true if an error occured, with an error message in the second return value.

Example:

local error, error_message = FS.Remove("myfile.txt")

if error then
    print("failed to delete myfile: " .. error_message)
end

FS.Rename(pathA: string, pathB: string) -> bool,string

Renames (or moves) pathA to pathB.

Returns true if an error occured, with an error message in the second return value.

FS.Copy(pathA: string, pathB: string) -> bool,string

Copies pathA to pathB.

Returns true if an error occured, with an error message in the second return value.

FS.GetFilename(path: string) -> string

Returns the last part of a path, which is usually the filename. Here are some example inputs + outputs:

input -> output

"my/path/a.txt"     -> "a.txt"
"somefile.txt"      -> "somefile.txt"
"/awesome/path"     -> "path"

FS.GetExtension(path: string) -> string

Returns the extension of the file, or an empty string if no extension exists. Here are some example inputs + outputs

input -> output

"myfile.txt"                    -> ".txt"
"somefile."                     -> "."
"/awesome/path"                 -> ""
"/awesome/path/file.zip.txt"    -> ".txt"
"myexe.exe"                     -> ".exe"

FS.GetParentFolder(path: string) -> string

Returns the path to the parent directory, i.e. the folder a file or folder is contained in. Here are some example inputs + outputs:

input -> output

"/var/tmp/example.txt"      -> "/var/tmp"
"/"                         -> "/"
"mydir/a/b/c.txt"           -> "mydir/a/b"

FS.Exists(path: string) -> bool

Returns true if the path exists, false if it doesn't.

FS.IsDirectory(path: string) -> bool

Returns true if the specified path is a directory, false if it's not. Note that false does NOT imply that the path is a file (see FS.IsFile()).

FS.IsFile(path: string) -> bool

Returns true if the specified path is a regular file (not a symlink, hardlink, block device, etc.), false if it's not. Note taht false does NOT imply that the path is a directory (see FS.IsDirectory()).

FS.ListDirectories(path: string) -> table

Returns a table of all the directories in the given path.

Example:

print(FS.ListDirectories("Resources"))
Results in:
{
    1: "Client",
    2: "Server"
}

FS.ListFiles(path: string) -> table

Returns a table of all the files in the given path.

Example:

print(FS.ListFiles("Resources/Server/examplePlugin"))
Results in:
{
    1: "example.json",
    2: "example.lua"
}

FS.ConcatPaths(...) -> string

Adds together (concatenates) all arguments with the system's preferred path separator.

Example:

FS.ConcatPaths("a", "b", "/c/d/e/", "/f/", "g", "h.txt")
results in
a/b/c/d/e/f/g/h.txt

Also resolves .., if that exists in the path at any point. This function is safer than concatenating strings in lua, and respects the platform's separators.

Please always use / as a separator when specifying paths, as this is cross-platform (windows, linux, macos, ...).

Events

Explanation

  • Arguments: List of arguments given to handlers of this event
  • Cancellable: Whether the event can be cancelled. If it can be cancelled, a handler can do so by returning 1, like return 1.

Summary of events

A player join triggers the following events in the given order:

  1. onPlayerAuth
  2. onPlayerConnecting
  3. onPlayerJoining
  4. onPlayerJoin

System Events

onInit

Arguments: NONE Cancellable: NO

Triggered right after all files in the plugin were initialized.

onShutdown

Arguments: NONE Cancellable: NO

Triggered when the server shuts down. Currently happens after all players were kicked.

onPlayerAuth

Arguments: player_name: string, player_role: string, is_guest: bool, identifiers: table -> beammp, ip Cancellable: YES

First event that gets triggered when a player wants to join.

onPlayerConnecting

Arguments: player_id: number Cancellable: NO

Triggered when a player first starts connecting, after onPlayerAuth.

onPlayerJoining

Arguments: player_id: number Cancellable: NO

Triggered when a player has finished loading all mods, after onPlayerConnecting.

onPlayerDisconnect

Arguments: player_id: number Cancellable: NO

Triggered when a player disconnects.

onChatMessage

Arguments: player_id: number, player_name: string, message: string Cancellable: YES

Triggered when a player sends a chat message. When cancelled, it will not show the chat message to anyone, not even the player who sent it.

onVehicleSpawn

Arguments: player_id: number, vehicle_id: number, data: string Cancellable: YES

Triggered when a player spawns a new vehicle. The data argument contains the car's config as json. When cancelled, the car is not spawned.

onVehicleEdited

Arguments: player_id: number, vehicle_id: number, data: string Cancellable: YES

Triggered when a player edits their vehicle and applies the edit. The data argument contains the car's change config as json. When cancelled, the edit is not applied.

onVehicleDeleted

Lua, among other things.

Custom Commands In order to implement custom commands for the server console, the event onConsoleInput can be used. This can be useful when you want to add a way for the server owner to signal something to your plugin, or to display internal state in a custom way.

Here’s an example:

function handleConsoleInput(cmd) local delim = cmd:find(' ') if delim then local message = cmd:sub(delim+1) if cmd:sub(1, delim-1) == "print" then return message end end end

Arguments: player_id: number, vehicle_id: number Cancellable: NO

Triggered when a player deletes their vehicle.

onVehicleReset

Arguments: player_id: number, vehicle_id: number, data: string Cancellable: NO

Triggered when a player resets their vehicle. data is the car's data as json.

onFileChanged

since v3.1.0

Arguments: path: string Cancellable: NO

Triggered if a file changes in the Resources/Server directory or any subdirectory of it.

Any file change in the Resources/Server/<plugin> directory (not in a subfolder of it) will trigger a Lua state reload, and an onFileChanged event.

Any file in subfolders of Resources/Server/<plugin>, such as Resources/Server/<plugin>/lua/stuff.lua, will not trigger a state reload and will only trigger an onFileChanged event. This way, you can reload it yourself in the correct way (or not reload it).

This applies to all files, not just .lua files.

The path is relative to the root of the server, for example Resources/Server/myplugin/myfile.txt. You can do further processing on this string with the FS.* family of functions, such as extracting the name or extension (FS.GetExtension(...), FS.GetFilename(...), ...).

Note: Files added after the server is started are not tracked as of v3.1.0.

Migrating from old Lua

This is a short run-down of the basic steps to take to migrate from old to new lua.

Understand how the new lua works

For this, please read through the section "Introduction" and all its subsections carefully. It's necessary to do the next steps properly.

Search & Replace

First, you should search and replace all MP functions. The substitution should add an MP. infront of all MP functions, except print().

Example:

local players = GetPlayers()
print(#players)
becomes

local players = MP.GetPlayers()
print(#players) -- note how print() doesn't change

Goodbye Threads, Hello Event Timers!

As discussed in the introduction, threads are event timers. For any calls to CreateThread, replace it with a call to CreateEventTimer. Carefully inspect the timing your old CreateThread had (the number was X per second), and think about what the event timer timeout value is for this (which is in milliseconds). Also keep in mind that instead of a function name, it takes an event name, so you will have to register an event as well.

Example:

CreateThread("myFunction", 2) -- calls "myFunction" twice per second
becomes

MP.RegisterEvent("myEvent", "myFunction") -- registering our event for the timer
MP.CreateEventTimer("myEvent", 500) -- 500 milliseconds = 2 times per second

If you have many event timers, it makes sense to see if you can combine them, e.g. by creating a "every minute" event and registering multiple functions to it which need to be called every minute, instead of having multiple event timers. Each event timer costs the server a little bit of time to trigger.

No more implicit event calling

You need to register all your events. You cannot rely on function names. In the old lua, this was unclear, but in the new lua this is usually enforced. A good pattern is:

MP.RegisterEvent("onChatMessage", "chatMessageHandler")
-- or 
MP.RegisterEvent("onChatMessage", "handleChatMessage")

This is a better pattern than calling the handler the same as the event, which is misleading and confusing.

Server Version 2.X


This is 2.x scripting. Only refer to this if your server is old/outdated (version 2.x.x). For the reference for 3.x scripting and beyond, see this page on 3.x scripting.

Notes

To get the output of a function in the server console you have to wrap it in a print() statement. For example: print(GetPlayerName(0)) will return the name of your server's first player.

<PlayersServerID> starts at 0.

List of available functions for scripting

GetPlayerName(playersServerID)

Returns the player's discord name as a string

function onPlayerJoin(playerID)
  local name = GetPlayerName(playerID)
  -- Do something
end

GetPlayerDiscordID(playersServerID)

Returns the player's discord name as a string

function onPlayerJoin(playerID)
  local name = GetPlayerDiscordID(playerID)
  -- Do something
end

GetPlayerHWID(playersServerID)

Returns the player's discord ID as a string

function onPlayerJoin(playerID)
  local name = GetPlayerHWID(playerID)
  -- Do something
end

GetPlayerVehicles(playersServerID)

Returns the player's vehicles as an object/array

function onChatMessage(playerID, senderName, message)
  local vehicleList = GetPlayerVehicles(playerID)
  for vehicleID, vehicleData in pairs(vehicleList) do
      -- Do something
    -- Could also be used to check how many vehicles a player have
  end
end

DropPlayer(playersServerID)

Drops the connection for a specific player. Essentially Kicking them

function onVehicleSpawn(playerID, vehicleID, vehicleData)
  -- Do something 
  DropPlayer(playerID)
end

SendChatMessage(playersServerID, message)

Sends a message over the network to the specified user. Use -1 for everyone

function onPlayerJoin(playerID)
  SendChatMessage(-1, "Someone just joined!")
end

CancelEvent() -- DEPRECIATED

Cancels the event from happening. This might be going soon. Use return 1 to cancel the event.

onInit()

If declared in a lua file, it will be called once C++ successfully finished loading the current lua file

function onInit()
  print("Server ready")
end

exit()

Will close the server

function onInit()
  print("Server Ready. But who needs a server which is running")
  exit() -- Stops the server
end

CreateThread(functionName, callInterval)

Will execute the function on a dedicated thread and it will run callInterval times a second. 1 = It will run every second.

function yourFunction()
  for i = 1,10 do
      SendChatMessage(-1, "Countdown: "..i)
      Sleep(1000)
  end
end
CreateThread("yourFunction", 30)

DEPRECIATED EXAMPLE Will execute the function on a dedicated thread

function yourFunction()
  for i = 1,10 do
      SendChatMessage(-1, "Countdown: "..i)
      Sleep(1000)
  end
end
CreateThread("yourFunction", 30)

StopThread(functionName)

Will stop trying to call the thread function of the current script

function yourFunction()
  delayExpired = false
  Sleep(10000)
  delayExpired = true
end
CreateThread("yourFunction", 30)
-- Do something
if not delayExpired then
  StopThread("yourFunction")
else
  -- Do something
end

Sleep(millisecs) - DEPRECIATED

Will pause execution for the amount of time specified (warning doing so will pause the entire server if you didn't create a thread)

function countdown()
  for i = 1,10 do
      SendChatMessage(-1, "Countdown: "..i)
      Sleep(1000)
  end
end
CreateThread("countdown", 10)

GetPlayerCount()

Will return how many players are connected

function onPlayerJoin(playerID)
  SendChatMessage(playerID, "You are the "..GetPlayerCount().."th player!"
end

RemoveVehicle(playerServerID, VehicleID)

Will despawn a vehicle

function onVehicleSpawn(playerID, vehicleID, vehicleData)
  if --[[ Vehicle data equal something it shouldn't be ]] then
      RemoveVehicle(playerID, vehicleIID)
  end
end

GetPlayers()

Will return a table of IDs with Names

local function onPlayerJoin(joinedPlayerID)
  local players = GetPlayers()
  for playerID, playerName in pairs(players) do
      if playerID == joinedPlayerID then
          -- Do something
      end
  end
end

RegisterEvent(eventName, functionName)

Will register that function to the event specified. Both must be strings

  function anyEvent()
      -- Do something
      end
  RegisterEvent("onAnyEventHappen", "anyEvent")
  -- Do something
  TriggerLocalEvent("onAnyEventHappen")

TriggerLocalEvent(eventName)

Will call every registered function in the same plugin folder.

  function anyEvent()
      -- Do something
      end
  RegisterEvent("onAnyEventHappen", "anyEvent")
  -- Do something
  TriggerLocalEvent("onAnyEventHappen")

TriggerGlobalEvent(eventName)

Will call every registered function with this event name.

  -- File A
  function anyEvent()
      -- Do something
      end
  RegisterEvent("onAnyEventHappen", "anyEvent")
      -- File B
  TriggerGlobalEvent("onAnyEventHappen")

TriggerClientEvent(playerServerID, eventName, data)

Will call that event with the given data on the specified client (-1 for broadcast)

  function onPlayerJoin(playerServerID)
     TriggerClientEvent(playerServerID, "anyEvent", "You just joined the server")
  end
  RegisterEvent("onAnyEventHappen", "anyEvent")

Set(configID, newValue)

will set a config setting to the new specified value table below|

  function onChatMessage(playerID, senderName, message)
    if playerID == adminPlayer then
      if message == --[[ anything ]] then
        Set(3, 10)
      end
    end
  end

List of available config settings for the Set() command

Note that these will not save to the config file.

Config ID Name Will only accept
0 Debug setting true or false
1 Private setting true or false
2 Max car per player number
3 Max players number
4 Map string
5 Name string
6 Description string
any other ID will result in a console warning

List of available events for scripting

Default Events

Example of how to use an event:

    function onInit()
    RegisterEvent("onPlayerJoin", "onPlayerJoin")
  end

  function onPlayerJoin(playerServerID)
    -- Do something
  end

If you dont want guests on your server:

    function onInit()
        print("noGuests Ready")
        RegisterEvent("onPlayerAuth","onPlayerAuth")
    end

    function onPlayerAuth(name, role, isGuest)
        if isGuest then
            return "You must be signed in to join this server!"
        end
    end

Event Parameters Description
onPlayerAuth The player's name, forum role, guest account (bool) A player has authenticated and is requesting to join
onPlayerConnecting The player's ID A player is loading in (Before loading the map)
onPlayerJoining The player's ID A player is loading the map and will be joined soon
onPlayerJoin The player's ID A player has joined and loaded in
onPlayerDisconnect The player's ID A player has disconnected
onChatMessage The sender's ID, name, and the chat message A chat message was sent. This would be good for making a commands system
onVehicleSpawn The player's ID, the vehicle ID, and the vehicle data This is called when someone spawns a vehicle
onVehicleEdited The player's ID, the vehicle ID, and the vehicle data This is called when someone edits a vehicle, or replaces their existing one
onVehicleDeleted The player's ID and the vehicle ID This is called when someone deletes a vehicle they own

Custom Events

Custom events can also be created for your own use. This is done very much the same to how the default ones are done.

Example of how to use a custom event:

    function onInit()
    RegisterEvent("myCustomEvent", "myCustomEvent")
  end

  function myCustomEvent(playerServerID, customData)
    -- Do something
  end

This can then be called either from client side or serverside using the respective functions.

Players

When a player connects to your server, they are assigned a serverID starting from 0 and counting upwards. serverIDs are reused; if a player leaves and re-joins they will not be assigned a new serverID, they will simply get another available one. When the server restarts, serverIDs will be reset.

Static Identifiers

Players in BeamMP have 3 static identifiers which can be obtained from their serverID being their name, discordID, and their hardwareID or HWID. (though the latter of the aforementioned isn't implemented, we will act as if it is) Each of the three ID types has their own origins and strength's/weaknesses to using them for player identification.

ID TYPE PROS CONS FUNCTION TO OBTAIN
name easy to obtain, straightforward not secure GetPlayerName()
discordID fairly secure inconvenient GetPlayerDiscordID()
HWID extremely secure hard to obtain GetPlayerHWID()

Vehicles

Vehicles in beamMP have 3 attributes that the server pays attention to, the owner's serverID, the vehicles vehicleID and it's data. The Owner's serverID is straight forward, it is the serverID, every vehicle also has an ID, vehicle IDs are not unique to the vehicle; two vehicles may have the same ID, assuming they're from different owners. Unlike serverIDs, vehicleIDs are reused, for example, if I have 4 vehicles, their IDs are 0, 1, 2 and, 3 if I delete the vehicle in vehicleID 2, I will have 0, 1 and, 3, when I spawn a new vehicle, the new vehicle will slot into ID 2. Lastly, the last attribute vehicles have is data, data contains a vehicle, name, parts, and other data; as the name implies. data is stored as a raw JSON string, so you will need a JSON library alternatively, you can manually step through the string and dig out the information you need.