From The Battle for Wesnoth Wiki
Revision as of 22:36, 3 June 2018 by Celtic Minstrel (talk | contribs) (Move wesnoth module docs to subpage)

Note: This page is is a work-in-progress and only reflects the current development version. For the equivalent documentation for 1.12, or more complete documentation for 1.13, see here.

All Lua API functionality is available in one of several global module tables, as well as some global functions which form the basic Lua API. The following core Lua modules are available and are documented on the Lua website:

  • basic — except dofile, require, and loadfile
  • coroutine
  • string
  • utf8
  • table
  • math — note that math.random is unsafe for MP usage; wesnoth provides a separate MP-safe random function
  • os — only the clock, date, time, and difftime functions are available (but keep in mind that they are not MP safe)
  • debug — only the traceback function is available

Wesnoth also provides several modules of its own, some of which are loaded by default while others require you to load them as needed.

Conventions used in this manual

On this page and any page linked from it, parameters will be shown in italic type, while literal names will be shown in bold type. Return values will be indicated by a right arrow (→) followed by a list of names in italics. Optional portions will be enclosed in square brackets.

For example, consider the following hypothetical definitions:

  • wesnoth.some_function(some_parameter [, some_optional_parameter]) → first_return_value, second_return_value

This is a function that returns multiple values and has optional parameters

  • some_value:some_method(some_parameter) → some_new_value
  • some_value.some_memberresult

For member variables, the right arrow may be replaced with a left arrow (←) if it is write-only, or a double-ended arrow (↔) if it is read-write.

Many functions and variables are only available in certain contexts. Currently, there are three possible contexts - plugins, map generators, and the game. Most Lua will run in the game kernel. If a function is only available in certain contexts, that will be indicated in parentheses at the beginning of the definition. For example:

  • (game only) wesnoth.game_exclusive_function(parameter) → result

Functions that take a variable number of parameters will use the string "..." to indicate this. For example:

  • wesnoth.variadic_function(required_param [, ...])

Wesnoth Modules

  • Core - The wesnoth module contains most of the core Wesnoth API. It is always loaded and available.
  • WML - The wml module contains functions for working with WML tables.