The Wesnoth Markup Language
The Wesnoth Markup Language (WML) is used to code almost everything in Wesnoth, including scenarios, units, savefiles, and the user interface layout. WML files are simple, human-readable text files, usually with the .cfg extension, with similarities to INI files and XML. A major feature in WML are macros, which are alike those found in the C language and similarily are handled by a preprocessor. Implementation-wise, WML files are handled mainly by the config class (and simple_wml in wesnothd).
This page is a collection of pointers to different common WML structures.
Note: this reference may contain slight inaccuracies, might not list all existing keys and tags or might contain some deprecated syntax. If you find that this reference doesn't give you the answer to how to implement some feature in WML, the most reliable way is to look at the WML code of existing units and campaigns that have done so.
How WML works
- SyntaxWML Description of WML syntax, and how to use variables
- PreprocessorRef the WML preprocessor syntax
- GrammarWML A more formal definition of the WML syntax. More useful for implementing a WML parser than for writing WML documents.
The following covers most of the possible toplevel tags in a typical main WML file. Some minor and dev-oriented tags (not intended for use by UMC) are omitted.
- GameConfigWML the top level [game_config] tag
- UnitsWML the top level [units] tag
- CoreWML the top level [core] tag
- AddonsWML the entry point for an add-on module
- CampaignWML the top level [campaign] tag
- CreditsWML how to describe the credits (the [about] tag)
- ScenarioWML the top level tags [scenario], [multiplayer], and [test]
- EraWML the top level [era] tag
- ModificationWML the top level [modification] and [resource] tags
- CampaignWML the top level [campaign] tag
- TerrainWML the top level [terrain_type] tag
- TerrainGraphicsWML, the top level [terrain_graphics] tag
- ThemeWML the top level [theme] tag
- LanguageWML the top level [language] tag
- LocaleWML the top level [locale] tag
- HelpWML the top level [help] tag
- BinaryPathWML the top level [binary_path] tag
- FontsWML the top level [fonts] tag
- Textdomains the [textdomain] tag
Some other files use the WML format, but with different tags.
- AchievementsWML the [achievement_group] and [achievement] tags.
- SavefileWML a description of the format of savegames
- PblWML a description of the format of server-uploadable campaigns
- SchemaWML a description of WML files that define the structure of other WML files
- DiffWML used to describe structural differences between preprocessed WML documents
- GUIToolkit creating dialogs
- EventWML how to describe an event
- FilterWML the construct to filter on units, locations, sides, weapons, vision, and WML data.
- ActionWML to describe the actions which occur when the event is fired
- ConditionalActionsWML actions that encapsulate conditional filters and the actions to execute if the conditions are met
- DirectActionsWML actions that directly affect gameplay: for example, creating a unit
- SingleUnitWML how to describe a unit (for uses such as placing one on the map)
- InternalActionsWML actions that WML uses internally: for example, storing a variable
- InterfaceActionsWML actions that do not affect gameplay: for example, displaying a message
- LuaWML how to code actions with the Lua language (BfW 1.14 and earlier)
- LuaAPI how to code actions with the Lua language (BfW 1.16 and later)
- AiWML how to describe parameters for AI
- EffectWML the construct to modify a unit
- DescriptionWML the structure of WML coded menus like the difficulty chooser of campaigns
- EditorWML tags controlling the post-1.4 editor's behavior
- MusicListWML for playing music (see also Available Music for a list of what's available)
Wesnoth ships with a library of predefined macros you should find useful in writing your own WML.
- WML Macros - description of all such macros.
- ReferenceWMLSyntax how this wiki and the pages it links to should be formatted
- ConventionsWML how to make your WML more readable
- Wml_optimisation how to make your WML code more efficient
- UsefulWMLFragments Various pieces of WML for various purposes. If you have some WML you're proud of that you think others can use, add it here.
- Maintenance tools for wmlindent, wmllint, wmlscope
- CommandMode commands are not strictly speaking part of WML, but they are useful for debugging it, and could be a little hard to find, so linking to them here makes sense.
- MultiplayerServerWML is used when communicating with the multiplayer server.
- CampaignServerWML is used when managing contributed campaigns on the campaign server.
- ImagePathFunctions (IPFs) are used when applying the color function to images, such as marking units as belonging to a team or in TerrainGraphics.
- Pango formatting shows ways to enrich descriptions (pango markup, which can generate basic html tags like <b>, <i>, <span> and others).
- Wesnoth_Formula_Language (WFL) often used with $() formulas.
- Syntax of preprocessor mini-language : symbols, macros, file inclusions...