menu_lua_api.md

Luanti Lua Mainmenu API Reference 5.10.0

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", "KeyEnter", "ExitButton", "EditBoxEnter" or "FullscreenChange"

Gamedata

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

{
    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.

"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_video_drivers()
  • get list of video drivers supported by engine (not all modes are guaranteed to work)
  • returns list of available video drivers' settings name and 'friendly' display name e.g. { {name="opengl", friendly_name="OpenGL"}, {name="software", friendly_name="Software Renderer"} }
  • first element of returned list is guaranteed to be the NULL driver
• 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.

{
    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.

{
    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_topleft_text(text)

• core.show_keys_menu()

• 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.

  -- 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:

    {
        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:

    {
        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

    {
        name             = "technical_id",
        type             = "mod" or "modpack" or "game" or "txp",
        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.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:

    {
        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)
  • returns

    {
        [1] = {
            path   = <full path to world>,
            name   = <name of world>,
            gameid = <gameid of world>,
        },
    }

• core.create_world(worldname, gameid, init_settings)
• core.delete_world(index)

Helpers

• core.get_us_time()
  • returns time with microsecond precision
• core.gettext(string) -> string
  • look up the translation of a string in the gettext message catalog
• fgettext_ne(string, ...)
  • call core.gettext(string), replace "$1"..."$9" with the given extra arguments and return the result
• fgettext(string, ...) -> string
  • same as fgettext_ne(), but calls core.formspec_escape before returning result
• core.parse_json(string[, nullvalue]) -> something (possible in async calls)
  • see core.parse_json (lua_api.md)
• dump(obj, dumped={})
  • Return object serialized as a string
• string:split(separator)
  • eg. string:split("a,b", ",") == {"a","b"}
• string:trim()
  • eg. string.trim("\n \t\tfoo bar\t ") == "foo bar"
• core.is_yes(arg) (possible in async calls)
  • returns whether arg can be interpreted as yes
• core.encode_base64(string) (possible in async calls)
  • Encodes a string in base64.
• core.decode_base64(string) (possible in async calls)
  • Decodes a string encoded in base64.
• core.urlencode(str): Encodes non-unreserved URI characters by a percent sign followed by two hex digits. See RFC 3986, section 2.3.

Async

• core.handle_async(async_job,parameters,finished)
  • execute a function asynchronously
  • async_job is a function receiving one parameter and returning one parameter
  • parameters parameter table passed to async_job
  • finished function to be called once async_job has finished the result of async_job is passed to this function

Limitations of Async operations

• No access to global lua variables, don't even try
• Limited set of available functions e.g. No access to functions modifying menu like core.start, core.close, core.show_path_select_dialog

Background music

The main menu supports background music. It looks for a main_menu sound in $USER_PATH/sounds. The same naming conventions as for normal sounds apply. This means the player can add a custom sound. It will be played in the main menu (gain = 1.0), looped.