StendhalScripting/LuaAPI

The following objects & functions are exposed to the Lua engine:

Objects

luajava

This is an object of the LuajavaLib library. It can be used to coerce Java static objects to Lua or create new Java object instances.

Example of exposing a static object & enums to Lua:

-- store a Java enum in a Lua global variable
ConversationStates = luajava.bindClass("games.stendhal.server.entity.npc.ConversationStates")

-- access the enum values like so
ConversationStates.IDLE

Example of creating an object instance:

-- store instance in local variable
local dog = luajava.newInstance("games.stendhal.server.entity.npc.SilentNPC")
-- access object methods like so
dog:setEntityClass("animal/puppy")
dog:setPosition(2, 5)

-- class with constructor using parameters
local speaker = luajava.newInstance("games.stendhal.server.entity.npc.SpeakerNPC", "Frank")
speaker:setOutfit("body=0,head=0,eyes=0,hair=5,dress=5")
speaker:setPosition(2, 6)

To make scripting easier, Stendhal employs a master script & some helper objects & methods to handle the functionality mentioned above. An explanation of these objects & methods follows.

logger

Manages logging in Lua via the org.apache.log4j.Logger class.

Methods:

• logger:info(message)
  • Prints an information level message to the console.
  • message: Text to be printed.
• logger:warn(message)
  • Prints a warning level message to the console.
  • message: Text to be printed.
• logger:error(message)
  • Prints an error level message to the console.
  • message: Text to be printed.

Example usage:

local zone = "0_semos_city"
if game:setZone(zone) then
	-- do something
else
	logger:error("Could not set zone: " .. zone)
end

properties

Defines functions for accessing Java system properties.

game

The main object that handles setting zone & adding entities to game.

Methods:

• game:add(npc)
• game:add(object) - Adds an object to the current zone.
• game:add(creature, x, y)
• game:remove(npc)
• game:remove(object)
• game:addGameEvent(source, event, params)
• game:setZone(name) - Sets the current zone.
• game:setZone(zone)
• game:getZone(rpobject)
• game:playerIsInZone(player, zoneName)
• game:getCreatures()
• game:getCreature(clazz)
• game:getItems()
• game:getItem(name)
• game:modify(entity)
• game:privateText(player, text)
• game:getMessage()
• game:setMessage(message)

entities

Methods:

• entities:getPlayer(name)
• entities:getNPC(name)
• entities:getItem(name)
• entities:getStackableItem(name)
• entities:createSpeakerNPC(name)
• entities:createSilentNPC()
• entities:setPath(entity, table, loop)
• entities:setPathAndPosition(entity, table, loop)
• entities:createSign(visible)
• entities:createShopSign(name, title, caption, seller)

quests

Adds helper functions for creating & manipulating quests & exposes select public methods of the games.stendhal.server.core.rp.StendhalQuestSystem class.

Methods:

• quests:createQuest(slotName, name)
• quests:load(quest)
• quests:unload(questName)
• quests:cache(quest)
• quests:register(quest) Alias for quests:cache(quest).
• quests:isLoaded(quest)
• quests:listAll(player)
• quests:list(player, questName)
• quests:listStates(player)
• quests:getQuest()
• quests:getQuestFromSlot(questSlot)
• quests:getOpen(player)
• quests:getCompleted(player)
• quests:getIncomplete(player, region)
• quests:getRepeatable(player)
• quests:getDescription(player, questName)
• quests:getLevelWarning(player, questeName)
• quests:getProgressDetails(player, questeName)
• quests:getNPCNamesForUnstartedInRegionForLevel(player, region)
• quests:getDescriptionForUnstartedInRegionFromNPCName(player, region, name)

quests.simple

A special class for creating a simple collect single item quest.

Methods:

• quests.simple:create(slotName, properName, npcName)
  • slotName: (string)
  • properName: (string)
  • npcName: (string)
  • returns: games.stendhal.server.maps.quests.SimpleQuestCreator.SimpleQuest instance.

SimpleQuest Object

Example:

-- create SimpleQuest instance
local quest = simpleQuest:create("wood_for_lua", "Wood for Lua", "Lua")

quest:setDescription("Lua needs help gathering wood.")
quest:setRequestReply("I need help gathering some wood. Will you help me?")
quest:setAcceptReply("Great!")
quest:setRewardReply("Thank a bunch!")
quest:setRejectReply("Fine! I don't need your help anyway.")
quest:setItemToCollect("wood", 5)
quest:setRepeatable(true)
quest:setRepeatDelay(10)
quest:setXPReward(50)
quest:setKarmaReward(5.0)
quest:addItemReward("rose", 3)
quest:addItemReward("money", 100)
quest:setRegion(Region.SEMOS_CITY)

quests:register(quest)

conditions

Object for creating games.stendhal.server.entity.npc.ChatCondition instances.

Methods:

• conditions.create(function)
• conditions.not(condition)
• conditions.not(value)
• conditions.and(conditionList)

actions

Object for creating games.stendhal.server.entity.npc.ChatAction instances.

Methods:

• actions.create(function)
  • function: A Lua function to be executed when ChatAction.fire is called.
• actions.multiple(actionList)
  • actionList: A Lua table containing ChatAction instances.

merchants

Exposes merchant handling classes & functions to Lua.

Methods:

• merchants.add(merchantType, npc, prices, addOffer)
• merchants.addSeller(npc, prices, addOffer)
• merchants.addBuyer(npc, prices, addOffer)

arrays

Handles some conversion of Java arrays & lists to Lua tables.

Methods:

• arrays.toTable(list)
  • Converts a Java array or list to a Lua table.
  • list: Java array or list.
  • returns: New Lua table.

grammar

Exposes the games.stendhal.common.grammar.Grammar parser instance to Lua.

Static Classes & Enumerations

ConversationStates

The games.stendhal.server.entity.npc.ConversationStates enum.

ConversationPhrases

The games.stendhal.server.entity.npc.ConversationPhrases class.

CollisionAction

The games.stendhal.server.entity.CollisionAction enum.

SkinColor

The games.stendhal.common.constants.SkinColor enum.

Direction

The games.stendhal.common.Direction enum.

DaylightPhase

The games.stendhal.server.core.rp.DaylightPhase enum.

Region

The games.stendhal.server.maps.Region class.

MathHelper

The games.stendhal.common.MathHelper class.

Color

The java.awt.Color class.

Supplemental Methods

A few convenience methods are added to make scripting easier.

String Manipulation

The following methods have been added to the built-in Lua string library.

• string.startsWith(st, prefix)
  • Checks if a string begins with a set of characters.
  • st: The string to be checked.
  • prefix: The prefix to be compared with.
  • returns: true if prefix matches the beginning characters of st.
• string.beginsWith(st, prefix)
  • This is just an alias for string.startsWith.
• string.endsWith(st, suffix)
  • Checks if a string ends with a set of characters.
  • st: The string to be checked.
  • suffix: The suffix to be compared with.
  • returns: true if suffix matches then end characters of st.
• string.trim(st)
  • Removes leading & trailing whitespace from a string.
  • st: The string to be trimmed.
  • returns: Trimmed string.
• string.ltrim(st)
  • Removes leading whitespace from a string.
  • st: The string to be trimmed.
  • returns: Trimmed string.
• string.rtrim(st)
  • Removes trailing whitespace from a string.
  • st: The string to be trimmed.
  • returns: Trimmed string.

Table Manipulation

The following methods have been added to the built-in Lua table library.

• table.clean(tbl)
  • Removes nil values from a table.
  • tbl: The table to be cleaned.
  • returns: Copy of tbl with nil values removed.
• table.concat(tbl1, tbl2)
  • Merges the contents of one table into another.
  • tbl1: The table receiving the new content.
  • tbl2: The table containing the content to be copied.

See Also

• Lua: Basics
• Lua: Stendhal Application