Luanti Lua Mainmenu API Reference 5.15.2

Introduction

The main menu is defined as a formspec by Lua in builtin/mainmenu/ Description of formspec language to show your menu is in lua_api.md

Images and 3D models

Directory delimiters change according to the OS (e.g. on Unix-like systems is /, on Windows is \). When putting an image or a 3D model inside a formspec, be sure to sanitize it first with core.formspec_escape(img); otherwise, any resource located in a subpath won't be displayed on OSs using \ as delimiter.

Callbacks

core.button_handler(fields): called when a button is pressed.
- fields = {name1 = value1, name2 = value2, ...}
core.event_handler(event)
- event: "MenuQuit" (derived from quit) or "FullscreenChange" The main menu may issue custom events, such as "Refresh" (server list).
core.on_before_close(): called before the menu is closed, either to exit or to join a game

Gamedata

The "gamedata" table is read when calling core.start(). It should contain:

lua

{
    playername     = <name>,
    password       = <password>,
    address        = <IP/address>,
    port           = <port>,
    selected_world = <index>, -- 0 for client mode
    singleplayer   = <true/false>,
}

Functions

core.start()
- start game session
core.close()
- exit engine
core.get_min_supp_proto()
- returns the minimum supported network protocol version
core.get_max_supp_proto()
- returns the maximum supported network protocol version
core.open_url(url)
- opens the URL in a web browser, returns false on failure.
- url must begin with http:// or https://
core.open_url_dialog(url)
- shows a dialog to allow the user to choose whether to open a URL.
- url must begin with http:// or https://
core.open_dir(path)
- opens the path in the system file browser/explorer, returns false on failure.
- Must be an existing directory.
core.share_file(path)
- Android only. Shares file using the share popup
core.get_version() (possible in async calls)
- returns current core version
core.get_formspec_version()
- returns maximum supported formspec version

Filesystem

To access specific subpaths, use DIR_DELIM as a directory delimiter instead of manually putting one, as different OSs use different delimiters. E.g.

lua

"my" .. DIR_DELIM .. "custom" .. DIR_DELIM .. "path" -- and not my/custom/path

core.get_builtin_path()
- returns path to builtin root
core.create_dir(absolute_path) (possible in async calls)
- absolute_path to directory to create (needs to be absolute)
- returns true/false
core.delete_dir(absolute_path) (possible in async calls)
- absolute_path to directory to delete (needs to be absolute)
- returns true/false
core.copy_dir(source,destination,keep_source) (possible in async calls)
- source folder
- destination folder
- keep_source DEFAULT true --> if set to false source is deleted after copying
- returns true/false
core.is_dir(path) (possible in async calls)
- returns true if path is a valid dir
core.extract_zip(zipfile,destination) [unzip within path required]
- zipfile to extract
- destination folder to extract to
- returns true/false
core.sound_play(spec, looped) -> handle
- spec = SimpleSoundSpec (see lua_api.md)
- looped = bool
handle:stop() or core.sound_stop(handle)
core.get_mapgen_names([include_hidden=false]) -> table of map generator algorithms registered in the core (possible in async calls)
core.get_cache_path() -> path of cache
core.get_temp_path([param]) (possible in async calls)
- param=true: returns path to a newly created temporary file
- otherwise: returns path to a newly created temporary folder

HTTP Requests

core.download_file(url, target) (possible in async calls)
- url to download, and target to store to
- returns true/false
core.get_http_api() (possible in async calls)
- returns HTTPApiTable containing http functions.
- The returned table contains the functions fetch_sync, fetch_async and fetch_async_get described below.
- Function only exists if Luanti server was built with cURL support.
HTTPApiTable.fetch_sync(HTTPRequest req): returns HTTPRequestResult
- Performs given request synchronously
HTTPApiTable.fetch_async(HTTPRequest req): returns handle
- Performs given request asynchronously and returns handle for HTTPApiTable.fetch_async_get
HTTPApiTable.fetch_async_get(handle): returns HTTPRequestResult
- Return response data for given asynchronous HTTP request

`HTTPRequest` definition

Used by HTTPApiTable.fetch and HTTPApiTable.fetch_async.

lua

{
    url = "http://example.org",

    timeout = 10,
    -- Timeout for connection in seconds. Default is 3 seconds.

    post_data = "Raw POST request data string" OR {field1 = "data1", field2 = "data2"},
    -- Optional, if specified a POST request with post_data is performed.
    -- Accepts both a string and a table. If a table is specified, encodes
    -- table as x-www-form-urlencoded key-value pairs.
    -- If post_data is not specified, a GET request is performed instead.

    user_agent = "ExampleUserAgent",
    -- Optional, if specified replaces the default Luanti user agent with
    -- given string

    extra_headers = { "Accept-Language: en-us", "Accept-Charset: utf-8" },
    -- Optional, if specified adds additional headers to the HTTP request.
    -- You must make sure that the header strings follow HTTP specification
    -- ("Key: Value").

    multipart = boolean
    -- Optional, if true performs a multipart HTTP request.
    -- Default is false.
}

`HTTPRequestResult` definition

Passed to HTTPApiTable.fetch callback. Returned by HTTPApiTable.fetch_async_get.

lua

{
    completed = true,
    -- If true, the request has finished (either succeeded, failed or timed
    -- out)

    succeeded = true,
    -- If true, the request was successful

    timeout = false,
    -- If true, the request timed out

    code = 200,
    -- HTTP status code

    data = "response"
}

Formspec

core.update_formspec(formspec)
core.get_table_index(tablename) -> index
- can also handle textlists
core.formspec_escape(string) -> string
- escapes characters [ ] \ , ; that cannot be used in formspecs
core.explode_table_event(string) -> table
- returns e.g. {type="CHG", row=1, column=2}
- type: "INV" (no row selected), "CHG" (selected) or "DCL" (double-click)
core.explode_textlist_event(string) -> table
- returns e.g. {type="CHG", index=1}
- type: "INV" (no row selected), "CHG" (selected) or "DCL" (double-click)
core.set_formspec_prepend(formspec)
- formspec: string to be added to every mainmenu formspec, to be used for theming.

GUI

core.set_background(type,texturepath,[tile],[minsize])
- type: "background", "overlay", "header" or "footer"
- tile: tile the image instead of scaling (background only)
- minsize: minimum tile size, images are scaled to at least this size prior doing tiling (background only)
core.set_clouds(<true/false>)
core.set_clouds_color(colorString)
core.set_sky_color(colorString)
- colorString: "#RRGGBB" format
core.set_topleft_text(text)
core.show_touchscreen_layout()
core.show_path_select_dialog(formname, caption, is_file_select)
- shows a path select dialog
- formname is base name of dialog response returned in fields
  - if dialog was accepted "_accepted" will be added to fieldname containing the path
  - if dialog was canceled "_cancelled" will be added to fieldname value is set to formname itself
- if is_file_select is true, a file and not a folder will be selected
- returns nil or selected file/folder
core.get_active_driver():
- technical name of active video driver, e.g. "opengl"
core.get_active_renderer():
- name of current renderer, e.g. "OpenGL 4.6"
core.get_active_irrlicht_device():
- name of current irrlicht device, e.g. "SDL"

core.get_window_info(): Same as server-side get_player_window_information API.

lua

-- Note that none of these things are constant, they are likely to change
-- as the player resizes the window and moves it between monitors
--
-- real_gui_scaling and real_hud_scaling can be used instead of DPI.
-- OSes don't necessarily give the physical DPI, as they may allow user configuration.
-- real_*_scaling is just OS DPI / 96 but with another level of user configuration.
{
    -- Current size of the in-game render target.
    --
    -- This is usually the window size, but may be smaller in certain situations,
    -- such as side-by-side mode.
    size = {
        x = 1308,
        y = 577,
    },

    -- Estimated maximum formspec size before Luanti will start shrinking the
    -- formspec to fit. For a fullscreen formspec, use this formspec size and
    -- `padding[0,0]`. `bgcolor[;true]` is also recommended.
    max_formspec_size = {
        x = 20,
        y = 11.25
    },

    -- GUI Scaling multiplier
    -- Equal to the setting `gui_scaling` multiplied by `dpi / 96`
    real_gui_scaling = 1,

    -- HUD Scaling multiplier
    -- Equal to the setting `hud_scaling` multiplied by `dpi / 96`
    real_hud_scaling = 1,

    -- Whether the touchscreen controls are enabled.
    -- Usually (but not always) `true` on Android.
    touch_controls = false,
}

Content and Packages

Content - an installed mod, modpack, game, or texture pack (txt) Package - content which is downloadable from the content db, may or may not be installed.

core.get_user_path() (possible in async calls)
- returns path to global user data, the directory that contains user-provided mods, worlds, games, and texture packs.
core.get_modpath() (possible in async calls)
- returns path to global modpath in the user path, where mods can be installed

core.get_modpaths() (possible in async calls)

returns table of virtual path to global modpaths, where mods have been installed The difference with core.get_modpath is that no mods should be installed in these directories by Luanti -- they might be read-only.

Ex:

lua

{
    mods = "/home/user/.minetest/mods",
    share = "/usr/share/minetest/mods", -- only provided when RUN_IN_PLACE=0

    -- Custom dirs can be specified by the MINETEST_MOD_DIR env variable
    ["/path/to/custom/dir"] = "/path/to/custom/dir",
}

core.get_clientmodpath() (possible in async calls)
- returns path to global client-side modpath
core.get_gamepath() (possible in async calls)
- returns path to global gamepath
core.get_texturepath() (possible in async calls)
- returns path to default textures

core.get_games() -> table of all games (possible in async calls)

name in return value is deprecated, use title instead.

returns a table (ipairs) with values:

lua

{
    id               = <id>,
    path             = <full path to game>,
    gamemods_path    = <path>,
    title            = <title of game>,
    menuicon_path    = <full path to menuicon>,
    author           = "author",
    --DEPRECATED:
    addon_mods_paths = {[1] = <path>,},
}

core.get_content_info(path)

returns

lua

{
    name             = "technical_id",
    type             = "mod" or "modpack" or "game" or "txp" or "unknown",
    title            = "Human readable title",
    description      = "description",
    author           = "author",
    path             = "path/to/content",
    textdomain = "textdomain", -- textdomain to translate title / description with
    depends          = {"mod", "names"}, -- mods only
    optional_depends = {"mod", "names"}, -- mods only
}

core.get_mod_list(path, virtual_path)
- Returns a flat list of mod and modpack information found within the specified path.
- Each entry consists of the fields name, author, release, description, path, virtual_path, is_name_explicit, is_modpack, modpack_depth.

core.check_mod_configuration(world_path, mod_paths)

Checks whether configuration is valid.
world_path: path to the world
mod_paths: list of enabled mod paths

returns:

lua

{
    is_consistent = true,  -- true is consistent, false otherwise
    unsatisfied_mods = {},  -- list of mod specs
    satisfied_mods = {}, -- list of mod specs
    error_message = "",  -- message or nil
}

core.get_content_translation(path, domain, string)
- Translates string using domain in content directory at path.
- Textdomains will be found by looking through all locale folders.
- String should contain translation markup from core.translate(textdomain, ...).
- Ex: core.get_content_translation("mods/mymod", "mymod", core.translate("mymod", "Hello World")) will translate "Hello World" into the current user's language using mods/mymod/locale/mymod.fr.tr.

Logging

core.debug(line) (possible in async calls)
- Always printed to stderr and logfile (print() is redirected here)
core.log(line) (possible in async calls)
core.log(loglevel, line) (possible in async calls)
- loglevel one of "error", "action", "info", "verbose"

Settings

core.settings:set(name, value)
core.settings:get(name) -> string or nil (possible in async calls)
core.settings:set_bool(name, value)
core.settings:get_bool(name) -> bool or nil (possible in async calls)
core.settings:save() -> nil, save all settings to config file

For a complete list of methods of the Settings object see lua_api.md

Worlds

core.get_worlds() -> list of worlds (possible in async calls)