mirror-chatterino2/docs/wip-plugins.md

Plugins

If Chatterino is compiled with the CHATTERINO_PLUGINS CMake option, it can load and execute Lua files. Note that while there are attempts at making this decently safe, we cannot guarantee safety.

Plugin structure

Chatterino searches for plugins in the Plugins directory in the app data, right next to Settings and Logs.

Each plugin should have its own directory.

Chatterino Plugins dir/
└── plugin_name/
    ├── init.lua
    ├── info.json
    └── data/
        └── This is where your data/configs can be dumped

init.lua will be the file loaded when the plugin is enabled. You may load other files using require global function.

info.json contains metadata about the plugin, like its name, description, authors, homepage link, tags, version, license name. The version field must be semver 2.0 compliant. The general idea of info.json will not change however the exact contents probably will, for example with permission system ideas. Example file:

{
  "$schema": "https://raw.githubusercontent.com/Chatterino/chatterino2/master/docs/plugin-info.schema.json",
  "name": "Test plugin",
  "description": "This plugin is for testing stuff.",
  "authors": ["Mm2PL"],
  "homepage": "https://github.com/Chatterino/Chatterino2",
  "tags": ["test"],
  "version": "0.0.0",
  "license": "MIT",
  "permissions": []
}

An example plugin is available at https://github.com/Mm2PL/Chatterino-test-plugin

Permissions

Plugins can have permissions associated to them. Unless otherwise noted functions don't require permissions. These are the valid permissions:

FilesystemRead

Allows the plugin to read from its data directory.

Example:

{
  ...,
  "permissions": [
    {
      "type": "FilesystemRead"
    },
    ...
  ]
}

FilesystemWrite

Allows the plugin to write to files and create files in its data directory.

Example:

{
  ...,
  "permissions": [
    {
      "type": "FilesystemWrite"
    },
    ...
  ]
}

Network

Allows the plugin to send HTTP requests.

Example:

{
  ...,
  "permissions": [
    {
      "type": "Network"
    },
    ...
  ]
}

Plugins with Typescript

If you prefer, you may use TypescriptToLua to typecheck your plugins. There is a chatterino.d.ts file describing the API in this directory. However, this has several drawbacks like harder debugging at runtime.

LuaLS type definitions

Type definitions for LuaLS are available in the /plugin-meta.lua file. These are generated from the C++ headers of Chatterino using a script.

API

The following parts of the Lua standard library are loaded:

• _G (most globals)
• io - except stdin, stdout, stderr. Some functions require permissions.
• math
• string
• table
• utf8

The official manual for them is available here.

Chatterino API

All Chatterino functions are exposed in a global table called c2. The following members are available:

log(level, args...)

Writes a message to the Chatterino log. The level argument should be a LogLevel member. All args should be convertible to a string with tostring().

Example:

c2.log(c2.LogLevel.Warning, "Hello, this should show up in the Chatterino log by default")

c2.log(c2.LogLevel.Debug, "Hello world")
-- Equivalent to doing qCDebug(chatterinoLua) << "[pluginDirectory:Plugin Name]" << "Hello, world"; from C++

LogLevel enum

This table describes log levels available to Lua Plugins. The values behind the names may change, do not count on them. It has the following keys:

• Debug
• Info
• Warning
• Critical

register_command(name, handler)

Registers a new command called name which when executed will call handler. Returns true if everything went ok, false if there already exists another command with this name.

Example:

function cmd_words(ctx)
    -- ctx contains:
    -- words - table of words supplied to the command including the trigger
    -- channel - the channel the command is being run in
    channel:add_system_message("Words are: " .. table.concat(ctx.words, " "))
end

c2.register_command("/words", cmd_words)

Limitations/known issues:

• Commands registered in functions, not in the global scope might not show up in the settings UI, rebuilding the window content caused by reloading another plugin will solve this.
• Spaces in command names aren't handled very well (https://github.com/Chatterino/chatterino2/issues/1517).

register_callback("CompletionRequested", handler)

Registers a callback (handler) to process completions. The callback takes a single table with the following entries:

• query: The queried word.
• full_text_content: The whole input.
• cursor_position: The position of the cursor in the input.
• is_first_word: Flag whether query is the first word in the input.

Example:

Input	query	full_text_content	cursor_position	is_first_word
foo│	foo	foo	3	true
fo│o	fo	foo	2	true
foo bar│	bar	foo bar	7	false
foo │bar	foo	foo bar	4	false

function string.startswith(s, other)
    return string.sub(s, 1, string.len(other)) == other
end

c2.register_callback(
    "CompletionRequested",
    function(event)
        if ("!join"):startswith(event.query) then
            ---@type CompletionList
            return { hide_others = true, values = { "!join" } }
        end
        ---@type CompletionList
        return { hide_others = false, values = {} }
    end
)

ChannelType enum

This table describes channel types Chatterino supports. The values behind the names may change, do not count on them. It has the following keys:

• None
• Direct
• Twitch
• TwitchWhispers
• TwitchWatching
• TwitchMentions
• TwitchLive
• TwitchAutomod
• TwitchEnd
• Irc
• Misc

Channel

This is a type that represents a channel. Existence of this object doesn't force Chatterino to hold the channel open. Should the user close the last split holding this channel open, your Channel object will expire. You can check for this using the Channel:is_valid() function. Using any other function on an expired Channel yields an error. Using any Channel member function on a non-Channel table also yields an error.

Some functions make sense only for Twitch channel, these yield an error when used on non-Twitch channels. Special channels while marked as is_twitch_channel() = true do not have these functions. To check if a channel is an actual Twitch chatroom use Channel:get_type() instead of Channel:is_twitch_channel().

Channel:by_name(name)

Finds a channel given by name. Returns the channel or nil if not open.

Some miscellaneous channels are marked as if they are specifically Twitch channels:

• /whispers
• /mentions
• /watching
• /live
• /automod

Example:

local pajladas = c2.Channel.by_name("pajlada")

Channel:by_twitch_id(id)

Finds a channel given by the string representation of the owner's Twitch user ID. Returns the channel or nil if not open.

Example:

local pajladas = c2.Channel.by_twitch_id("11148817")

Channel:get_name()

On Twitch returns the lowercase login name of the channel owner. On IRC returns the normalized channel name.

Example:

-- Note: if the channel is not open this errors
pajladas:get_name()  -- "pajlada"

Channel:get_type()

Returns the channel's type. See ChannelType enum.

Channel:get_display_name()

Returns the channel owner's display name. This can contain characters that are not lowercase and even non-ASCII.

Example:

local saddummys = c2.Channel.by_name("saddummy")
saddummys:get_display_name() -- "서새봄냥"

Channel:send_message(message[, execute_commands])

Sends a message to the channel with the given text. If execute_commands is not present or false commands will not be executed client-side, this affects all user commands and all Twitch commands except /me.

Examples:

-- times out @Mm2PL
pajladas:send_message("/timeout mm2pl 1s test", true)

-- results in a "Unknown command" error from Twitch
pajladas:send_message("/timeout mm2pl 1s test")

-- Given a user command "hello":
-- this will execute it
pajladas:send_message("hello", true)
-- this will send "hello" literally, bypassing commands
pajladas:send_message("hello")

function cmd_shout(ctx)
    table.remove(ctx.words, 1)
    local output = table.concat(ctx.words, " ")
    ctx.channel:send_message(string.upper(output))
end
c2.register_command("/shout", cmd_shout)

Limitations/Known issues:

• It is possible to trigger your own Lua command with this causing a potentially infinite loop.

Channel:add_system_message(message)

Shows a system message in the channel with the given text.

Example:

pajladas:add_system_message("Hello, world!")

Channel:is_twitch_channel()

Returns true if the channel is a Twitch channel, that is its type name has the Twitch prefix. This returns true for special channels like Mentions. You might want Channel:get_type() == "Twitch" if you want to use Twitch-specific functions.

Channel:get_twitch_id()

Returns the string form of the channel owner's Twitch user ID.

Example:

pajladas:get_twitch_id() -- "11148817"

Channel:is_broadcaster()

Returns true if the channel is owned by the current user.

Channel:is_mod()

Returns true if the channel can be moderated by the current user.

Channel:is_vip()

Returns true if the current user is a VIP in the channel.

HTTPMethod enum

This table describes HTTP methods available to Lua Plugins. The values behind the names may change, do not count on them. It has the following keys:

• Get
• Post
• Put
• Delete
• Patch

HTTPResponse

An HTTPResponse is a table you receive in the callback after a completed HTTPRequest.

HTTPResponse.data()

This function returns the data received from the server as a string. Usually this will be UTF-8-encoded however that is not guaranteed, this could be any binary data.

HTTPResponse.error()

If an error happened this function returns a human readable description of it.

It returns something like: "ConnectionRefusedError", "401".

HTTPResponse.status()

This function returns the HTTP status code of the request or nil if there was an error before a status code could be received.

HTTPRequest

Allows you to send an HTTP request to a URL. Do not create requests that you don't want to call execute() on. For the time being that leaks callback functions and all their upvalues with them.

HTTPRequest.create(method, url)

Creates a new HTTPRequest. The method argument is an HTTPMethod. The url argument must be a string containing a valid URL (ex. https://example.com/path/to/api).

local req = c2.HTTPRequest.create(c2.HTTPMethod.Get, "https://example.com")
req:on_success(function (res)
    print(res:data())
end)
req:execute()

HTTPRequest:on_success(callback)

Sets the success callback. It accepts a function that takes a single parameter of type HTTPResponse. The callback will be called on success. This function returns nothing.

HTTPRequest:on_error(callback)

Sets the error callback. It accepts a function that takes a single parameter of type HTTPResponse. The callback will be called if the request fails. To see why it failed check the error field of the result. This function returns nothing.

HTTPRequest:finally(callback)

Sets the finally callback. It accepts a function that takes no parameters and returns nothing. It will be always called after success or error. This function returns nothing.

HTTPRequest:set_timeout(timeout)

Sets how long the request will take before it times out. The timeout parameter is in milliseconds. This function returns nothing.

HTTPRequest:set_payload(data)

Sets the data that will be sent with the request. The data parameter must be a string. This function returns nothing.

HTTPRequest:set_header(name, value)

Adds or overwrites a header in the request. Both name and value should be strings. If they are not strings they will be converted to strings. This function returns nothing.

HTTPRequest:execute()

Sends the request. This function returns nothing.

local url = "http://localhost:8080/thing"
local request = c2.HTTPRequest.create("Post", url)
request:set_timeout(1000)
request:set_payload("TEST!")
request:set_header("X-Test", "Testing!")
request:set_header("Content-Type", "text/plain")
request:on_success(function (res)
    print('Success!')
    -- Data is in res.data
    print(res:status())
end)
request:on_error(function (res)
    print('Error!')
    print(res:status())
    print(res:error())
end)
request:finally(function ()
    print('Finally')
end)
request:execute()

-- This prints:
-- Success!
-- [content of /thing]
-- 200
-- Finally

-- Or:
-- Error!
-- nil
-- ConnectionRefusedError

Input/Output API

These functions are wrappers for Lua's I/O library. Functions on file pointer objects (FILE*) are not modified or replaced. You can read the documentation for them here. Chatterino does not give you stdin and stdout as default input and output respectively. The following objects are missing from the io table exposed by Chatterino compared to Lua's native library: stdin, stdout, stderr.

close([file])

Closes a file. If not given, io.output() is used instead.

See official documentation

flush()

Flushes io.output().

See official documentation

input([file_or_name])

When called with no arguments this function returns the default input file. This variant requires no permissions.

When called with a file object, it will set the default input file to the one given. This one also requires no permissions.

When called with a filename as a string, it will open that file for reading. Equivalent to: io.input(io.open(filename)). This variant requires the FilesystemRead permission and the given file to be within the plugin's data directory.

See official documentation

lines([filename, ...])

With no arguments this function is equivalent to io.input():lines("l"). See Lua documentation for file:flush(). This variant requires no permissions.

With filename given it is most like io.open(filename):lines(...). This variant requires the FilesystemRead permission and the given file to be within the plugin's data directory.

See official documentation

open(filename [, mode])

This functions opens the given file with a mode. It requires filename to be within the plugin's data directory. A call with no mode given is equivalent to one with mode="r". Depending on the mode this function has slightly different behavior:

Mode	Permission	Read?	Write?	Truncate?	Create?
r read	FilesystemRead	Yes	No	No	No
w write	FilesystemWrite	No	Yes	Yes	Yes
a append	FilesystemWrite	No	Append	No	Yes
r+ update	FilesystemWrite	Yes	Yes	No	No
w+ update	FilesystemWrite	Yes	Yes	Yes	Yes
a+ update	FilesystemWrite	Yes	Append	No	Yes

To open a file in binary mode add a b at the end of the mode.

See official documentation

output([file_or_name])

This is identical to io.input() but operates on the default output and opens the file in write mode instead. Requires FilesystemWrite instead of FilesystemRead.

See official documentation

popen(exe [, mode])

This function is unavailable in Chatterino. Calling it results in an error message to let you know that it's not available, no permissions needed.

See official documentation

read(...)

Equivalent to io.input():read(...). See io.input() and file:read().

See official documentation

tmpfile()

This function is unavailable in Chatterino. Calling it results in an error message to let you know that it's not available, no permissions needed.

See official documentation

type(obj)

This functions allows you to tell if the object is a file, a closed file or a different bit of data.

See official documentation

write(...)

Equivalent to io.output():write(...). See io.output() and file:write().

See official documentation

Changed globals

load(chunk [, chunkname [, mode [, env]]])

This function is only available if Chatterino is compiled in debug mode. It is meant for debugging with little exception. This function behaves really similarity to Lua's load, however it does not allow for bytecode to be executed. It achieves this by forcing all inputs to be encoded with UTF-8.

See official documentation

require(modname)

This is Lua's require() function. However, the searcher and load configuration is notably different from the default:

• Lua's built-in dynamic library searcher is removed,
• package.path is not used, in its place are two searchers,
• when require() is used, first a file relative to the currently executing file will be checked, then a file relative to the plugin directory,
• binary chunks are never loaded,
• files inside of the plugin data directory are never loaded

As in normal Lua, dots are converted to the path separators ('/' on Linux and Mac, '\' on Windows).

Example:

require("stuff") -- executes Plugins/name/stuff.lua or $(dirname $CURR_FILE)/stuff.lua
require("dir.name") -- executes Plugins/name/dir/name.lua or $(dirname $CURR_FILE)/dir/name.lua
require("binary") -- tried to load Plugins/name/binary.lua and errors because binary is not a text file
require("data.file") -- tried to load Plugins/name/data/file.lua and errors because that is not allowed

print(Args...)

The print global function is equivalent to calling c2.log(c2.LogLevel.Debug, Args...)