m (→City: emphasis) |
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There are several contexts where scripting is used in Freeciv. Not everything documented here can be used in every context. For instance, methods to read game state can be used in most contexts, but methods to directly change it can only be used in a script running on the server. |
There are several contexts where scripting is used in Freeciv. Not everything documented here can be used in every context. For instance, methods to read game state can be used in most contexts, but methods to directly change it can only be used in a script running on the server. |
||
⚫ | |||
{{Lua/table/row|header}} |
{{Lua/table/row|header}} |
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+ | |||
⚫ | |||
! Scope |
! Scope |
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! Definition |
! Definition |
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Text formatting indicates the current status of each definition: |
Text formatting indicates the current status of each definition: |
||
⚫ | |||
{{Lua/table/row|header}} |
{{Lua/table/row|header}} |
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+ | |||
⚫ | |||
! Status |
! Status |
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{{Lua/table/row|common}} |
{{Lua/table/row|common}} |
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| (inspirer) |
| (inspirer) |
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| 2.5 |
| 2.5 |
||
− | | Returns whether the city would produce partisans if conquered from player '''inspirer''', taking into account original owner, nationality, and the 'Inspire_Partisans' effect.<br>The default 'city_lost' handler treats the return from this as boolean (greater than zero gives partisans), but a custom handler and ruleset could give different behaviour with different values of the 'Inspire_Partisans' effect. |
+ | | Returns whether the city would produce partisans if conquered from player '''inspirer''', taking into account original owner, nationality, and the 'Inspire_Partisans' effect.<br />The default 'city_lost' handler treats the return from this as boolean (greater than zero gives partisans), but a custom handler and ruleset could give different behaviour with different values of the 'Inspire_Partisans' effect. |
{{Lua/table/end}} |
{{Lua/table/end}} |
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| (name) |
| (name) |
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| 2.4 |
| 2.4 |
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+ | | (name) may be either 'Fortress', 'Airbase', 'Buoy', or any base type defined in the ruleset. |
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− | | |
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{{Lua/table/row|game}} |
{{Lua/table/row|game}} |
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| bool |
| bool |
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| (name) |
| (name) |
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| 2.5 |
| 2.5 |
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+ | | (name) may be either 'Road', 'Railroad', 'River', or any road type defined in the ruleset. |
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− | | |
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{{Lua/table/row|game}} |
{{Lua/table/row|game}} |
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| bool |
| bool |
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| (name) |
| (name) |
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| 2.6 |
| 2.6 |
||
+ | | (name) may be either the name of a base or a road type. See (Tile):has_base() and (Tile):has_road(). |
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− | | |
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{{Lua/table/row|game}} |
{{Lua/table/row|game}} |
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| Iterator (Unit) |
| Iterator (Unit) |
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== Reference Links == |
== Reference Links == |
||
− | The Scripting API is defined in <tt> |
+ | The Scripting API is defined in <tt> </tt> |
+ | *<tt>.pkg</tt> files, and that must be the canonical reference to this API. |
||
Links for the current development code (trunk) can be found at [[#Legend]]. For older/stable branches, see the following table. Please see these links for future updates, or if you suspect something in this Reference is wrong. |
Links for the current development code (trunk) can be found at [[#Legend]]. For older/stable branches, see the following table. Please see these links for future updates, or if you suspect something in this Reference is wrong. |
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| <abbr title="search for signals_create">[http://svn.gna.org/viewcvs/freeciv/branches/S2_1/server/scripting/script_signal.c c]</abbr> |
| <abbr title="search for signals_create">[http://svn.gna.org/viewcvs/freeciv/branches/S2_1/server/scripting/script_signal.c c]</abbr> |
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|} |
|} |
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− | [[Category:Event scripting]] |
Revision as of 14:52, 20 July 2014
Every event or action should have information about which versions of Freeciv support it. Important: Anything documented about unreleased versions can change at any time before the final release.
Legend
An argument with a question mark '?' is allowed to be empty. The empty value is 'nil'.
There are several contexts where scripting is used in Freeciv. Not everything documented here can be used in every context. For instance, methods to read game state can be used in most contexts, but methods to directly change it can only be used in a script running on the server.
|- style="background:#EEE;color:black"
Scope | Definition |
---|---|
Common (all Lua instances) | tolua_common_a.pkg tolua_common_z.pkg |
Signals (all current Lua instances) | tolua_signal.pkg |
Game (server, client, fcdb) | tolua_game.pkg |
Server (ruleset) only | tolua_server.pkg |
Client only | tolua_client.pkg |
FCDB (server) only | tolua_fcdb.pkg |
Text formatting indicates the current status of each definition:
|- style="background:#EEE;color:black"
Status |
---|
Current. |
Deprecated; do not use in new code. |
Internal; may disappear without notice; do not use. |
Not yet implemented. |
Modules
Module functions are accessed as members of the module:
module.function(..)
const
New in 2.4. This Lua constants implementation is included as const.
log
Logging facilities from Lua script. This is the preferred way to emit textual output from Freeciv Lua scripts. Messages emitted with these functions will be sent to an appropriate place, which will differ depending on the context.
Module log | ||||
(return) type | function name / variable | arguments | ver | comments |
- | log.base | (level, message) | 2.4 | Do not call this function directly but use the functions below for the different log levels. |
- | log.fatal | (message) | 2.4 | |
- | log.error | (message) | 2.4 | |
- | log.normal | (message) | 2.4 | |
- | log.verbose | (message) | 2.4 | |
- | log.debug | (message) | 2.4 |
game
This module is used for game related information.
Module game | ||||
(return) type | function name / variable | arguments | ver | comments |
int | game.turn | () |
find
Functions in this module are used to acquire objects for further manipulation, given various kinds of identifying information. Functions are overloaded so that a given object can be identified in several ways.
Module find | ||||
(return) type | function name / variable | arguments | ver | comments |
Player | find.player | (player_id) | ||
Player | find.leader | (nation_name) | - | Missing. |
Player | find.player | (player_name) | - | Missing. |
City | find.city | (player?, city_id) | ||
City | find.city | (player, city_name) | - | Missing. |
Unit | find.unit | (player?, unit_id) | If player is specified, restricts search to units of that player and returns nil if the unit exists but belongs to someone else. | |
Tile | find.tile | (nat_x, nat_y) | Native coordinates. | |
Tile | find.tile | (tile_id) | 2.2.1 | |
Government | find.government | (government_id) | ||
Government | find.government | (name) | ||
Nation_Type | find.nation_type | (nation_type_id) | ||
Nation_Type | find.nation_type | (name) | ||
Building_Type | find.building_type | (building_type_id) | ||
Building_Type | find.building_type | (name) | ||
Unit_Type | find.unit_type | (unit_type_id) | ||
Unit_Type | find.unit_type | (name) | ||
Unit_Type | find.role_unit_type | (role_name, player?) | 2.2 | If player is not nil, role_unit_type returns the best suitable unit this player can build. If player is nil, returns first unit for that role. |
Unit | find.transport_unit | (player, unit_type, tile) | 2.3 | Return an existing unit that can transport unit_type at tile. Intended to be used with create_unit_full. |
Unit_Type | find.a_unit_type | (role, role_tech) | - | Missing. |
Tech_Type | find.tech_type | (tech_type_id) | ||
Tech_Type | find.tech_type | (name) | ||
Terrain | find.terrain | (terrain_id) | ||
Terrain | find.terrain | (name) | ||
String | find.signal | (index) | 2.4 | Can be used to iterate over all defined signals (until nil is returned). |
String | find.signal_callback | (signal_name, index) | 2.4 | Can be used to iterate over all callbacks currently associated with a given signal. |
effects
Calculate the current value of a ruleset effect. Effect names are the same as in rulesets, e.g., "Upkeep_Free".
Module effects | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | effects.world_bonus | (effect_type_name) | 2.3 | |
Number | effects.player_bonus | (player, effect_type_name) | 2.3 | |
Number | effects.city_bonus | (city, effect_type_name) | 2.3 |
direction
Module direction | ||||
(return) type | function name / variable | arguments | ver | comments |
Direction | direction:str2dir | (str) | 2.4 | Turns a string like "north", "southwest", etc into a Direction object. |
notify
event is an event type from the E module, for example E.SCRIPT. These correspond to the categories that the client can filter on, and are defined in common/events.c.
Module notify | ||||
(return) type | function name / variable | arguments | ver | comments |
- | notify.embassies_msg | (player, tile, event, message) | Basic function for events. Do not call direct! | |
- | notify.event_msg | (player, tile, event, message) | Basic function for events. Do not call direct! | |
- | notify.all | (message) | Send all players a message with type E.SCRIPT. | |
- | notify.player | (player?, message) | Send a specific player a message with type E.SCRIPT. | |
- | notify.event | (player?, tile?, event, message) | Send a specific player or all players (player nil) a message with an arbitrary type, optionally drawing attention to a particular tile. | |
- | notify.embassies | (player, tile?, event, message) | Send a message to all players who have an embassy with player. |
server
Module server | ||||
(return) type | function name / variable | arguments | ver | comments |
- | server.save | (filename?) | 2.4 | As with the /save command, if filename is empty, the server chooses an appropriate filename. |
Boolean | server.started | () | 2.4 | |
Number | server.civilization_score | (player) | 2.4 | Added in 2.3 as (Player).civilization_score() |
String | server.setting.get | (name) | 2.4 | Return the value of a server setting as a string. |
edit
The edit module was added in 2.4; previously, most of these functions were available with unqualified names (e.g., player_victory()). For these, the "ver" column shows when the original, unadorned function appeared in Freeciv.
Module edit | ||||
(return) type | function name / variable | arguments | ver | comments |
Unit | edit.create_unit | (player, tile, unit_type, veteran_level, homecity?, moves_left) | moves_left: in internal units (3 = a single move), or -1 for the unit's full movement points. | |
Unit | edit.create_unit_full | (player, tile, unit_type, veteran_level, homecity?, moves_left, hp_left, transport?) | (2.3) | More complex version of create_unit() allowing creation of unit already loaded on the Unit passed as transport (use find.transport_unit() to locate suitable transport). hp_left: -1 means full HP for the unit. |
Boolean | edit.unit_move | (unit, moveto, movecost) | 2.4 | movecost is in internal units, where 3 = a single move. Returns false if unit died. Very few checks -- be careful! |
Boolean | edit.unit_teleport | (unit, dest) | 2.4 | Moves unit without subtracting move points, then checks if it landed in inhospitable terrain or among enemies. Returns false if unit died. |
- | edit.unit_turn | (unit, direction) | 2.4 | Change unit orientation to face direction. |
- | edit.create_base | (tile, name, player?) | (2.2) | player is the owner for territory-claiming base types. |
- | edit.create_road | (tile, name) | 2.5 | |
- | edit.create_extra | (tile, name) | 2.6 | |
- | edit.tile_set_label | (tile, labelstring) | 2.5 | Set a textual label for the tile. |
- | edit.create_city | (player, tile, name?) | If name is nil, one is randomly selected as appropriate for the player's nation. | |
Player | edit.create_player | (username, Nation_Type, ai_type?) | (2.3) | The new player has no units or cities. ai_type was added in 2.4; it is a string name for an AI module, and in most case should be left as 'nil'. |
- | edit.change_gold | (player, amount) | ||
Tech_Type | edit.give_technology | (player, technology?, reason) | Returns nil if player already has technology. You may pass nil for technology to grant a random tech. reason is passed to the "tech_researched" script signal. | |
Boolean | edit.mod_trait | (player, trait, mod) | 2.5 | Change value of player's trait by mod. Returns false for failure,
such as illegal trait name. |
- | edit.player_victory | (player) | 2.4 | New in 2.2 as (Player):victory(). |
Boolean | edit.unleash_barbarians | (tile) | (2.2) | Return value is false if any units on the tile were killed (or would have been killed, if there were no units). |
- | edit.place_partisans | (tile, player, count, sq_radius) | (2.3) | |
Player | edit.civil_war | (player, probability) | 2.4 | Possibly throw a player into civil war. probability is the percentage chance of the civil war occurring (use 100 for certainty), or if it is zero, the normal calculation is used (affected by government, happiness, etc). Takes no account of the 'civilwarsize' server option (but the player must have at least two cities). If the chance is not met, nothing happens. If the chance is met, civil war happens as usual, with appropriate messages sent to the players. Returns the new AI player, or nil. |
- | edit.climate_change | (climate_change_type, effect) | 2.4 | Cause global climate change. type can be edit.GLOBAL_WARMING or edit.NUCLEAR_WINTER. effect is the magnitude of the effect (approximately, the number of tiles affected). Does not print any messages, or affect the counters for pollution/fallout-related climate change. Works regardless of 'global_warming' and 'nuclear_winter' server options. |
signal
Signals are emitted by the server when certain events occurs (see #Events for a list of specific signals).
Signal emission invokes all associated callbacks in the order they were connected. A callback can stop the current signal emission, preventing callbacks connected after it from being invoked, by returning true.
Module signal | ||||
(return) type | function name / variable | arguments | ver | comments |
- | signal.connect | (signal_name, callback_name) | ||
- | signal.remove | (signal_name, callback_name) | 2.4 | |
- | signal.defined | (signal_name, callback_name) | 2.4 | |
- | signal.replace | (signal_name, callback_name) | 2.4 | |
- | signal.list | () | 2.4 | List all signals as well as any callbacks, via log.normal(). Intended for debugging. |
chat
Module chat | ||||
(return) type | function name / variable | arguments | ver | comments |
- | chat.base | (message) | 2.4 | Do not call directly. |
- | chat.msg | (format, ...) | 2.4 | Add a message to the local chat window, using string.format to interpolate the rest of the arguments into format. Does not send anything to the server. |
auth
See doc/README.fcdb for the use of this module.
Module auth | ||||
(return) type | function name / variable | arguments | ver | comments |
String | auth.get_username | (Connection) | 2.4 | |
String | auth.get_ipaddr | (Connection) | 2.4 | |
Boolean | auth.set_password | (Connection, password) | 2.4 | |
String | auth.get_password | (Connection) | 2.4 |
fcdb
The Freeciv database (fcdb) module.
See doc/README.fcdb for the use of this module.
Module fcdb | ||||
(return) type | function name / variable | arguments | ver | comments |
String | fcdb.option | (type) | 2.4 | Use it to get the value of a fcdb option. In 2.4, this must be one of the parameters fcdb.param.HOST, USER, PORT, PASSWORD, DATABASE, TABLE_USER, TABLE_LOG, BACKEND. From 2.5, it can be any string (fcdb.param.* mappings are provided for backward compatibility).) |
Types
Types functions are accessed as members of the module (=type)
module.function(..)
or as a function of a variable of the given type
type t t:function()
Player
Type Player | ||||
(return) type | function name / variable | arguments | ver | comments |
String | (Player).name | |||
Nation_Type | (Player).nation | |||
Boolean | (Player).ai_controlled | was ai_data in 2.2, ai in 2.1. | ||
Boolean | (Player).is_alive | 2.4 | ||
Number | (Player).id | Removed in 2.2.0, restored in 2.2.1. | ||
Boolean | (Player):is_human | () | Same information as ai_controlled. | |
Number | (Player):num_cities | () | ||
Number | (Player):num_units | () | ||
Boolean | (Player):has_wonder | (building) | 2.2 | |
Boolean | (Player):knows_tech | (tech) | 2.3 | |
Number | (Player):gold | () | 2.3 | |
Iterator (Unit) | (Player):units_iterate | () | 2.3 | |
Iterator (City) | (Player):cities_iterate | () | 2.3 | |
Boolean | (Player):exists | () | 2.4 | |
Unit | (Player):create_unit | (tile, unit_type, veteran_level, homecity?, moves_left) | 2.4 | See edit.create_unit(). |
Unit | (Player):create_unit_full | (tile, unit_type, veteran_level, homecity?, moves_left, hp_left, transport?) | 2.4 | See edit.create_unit_full(). |
- | (Player):create_city | (tile, name) | 2.4 | See edit.create_city(). |
- | (Player):change_gold | (amount) | 2.4 | See edit.change_gold(). |
Tech_Type | (Player):give_technology | (technology?, reason) | 2.4 | See edit.give_technology(). |
Player | (Player):civil_war | (probability) | 2.4 | See edit.civil_war(). |
- | (Player):victory | () | 2.2 | See edit.player_victory(). |
Number | (Player):civilization_score | () | 2.3 | See server.civilization_score(). |
City
Type City | ||||
(return) type | function name / variable | arguments | ver | comments |
String | (City).name | |||
Player | (City).owner | |||
Player | (City).original | 2.3 | The player who originally built the city. | |
Tile | (City).tile | () | 2.4 | was variable up to 2.3 |
Number | (City).size | () | 2.4 | was variable in 2.3 |
Number | (City).id | |||
Boolean | (City):has_building | (building) | 2.2 | |
Boolean | (City):exists | () | 2.2.1 | |
Number | (City):map_sq_radius | () | 2.3 | |
Number | (City):inspire_partisans | (inspirer) | 2.5 | Returns whether the city would produce partisans if conquered from player inspirer, taking into account original owner, nationality, and the 'Inspire_Partisans' effect. The default 'city_lost' handler treats the return from this as boolean (greater than zero gives partisans), but a custom handler and ruleset could give different behaviour with different values of the 'Inspire_Partisans' effect. |
Unit
Type Unit | ||||
(return) type | function name / variable | arguments | ver | comments |
Unit_Type | (Unit).utype | |||
Player | (Unit).owner | |||
Number | (Unit).homecity | was (Unit).homecity_id in 2.1. | ||
Tile | (Unit).tile | () | 2.4 | was variable up to 2.3. |
Number | (Unit).id | |||
City | (Unit):get_homecity | () | Same information as homecity. Was (Unit):homecity() in 2.1. | |
Boolean | (Unit):is_on_possible_city_tile | () | 2.2 | Could a settler unit build a city here? |
Boolean | (Unit):exists | () | 2.2.1 | |
Direction | (Unit):facing | () | 2.4 | The current unit orientation. |
Boolean | (Unit):move | (moveto, movecost) | 2.4 | See edit.unit_move(). |
Boolean | (Unit):teleport | (dest) | 2.4 | See edit.unit_teleport(). |
- | (Unit):turn | (direction) | 2.4 | See edit.unit_turn(). |
Tile
Type Tile | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | (Tile).nat_x | Native coordinate. | ||
Number | (Tile).nat_y | Native coordinate. | ||
Number | (Tile).x | 2.4 | Map coordinate. | |
Number | (Tile).y | 2.4 | Map coordinate. | |
Terrain | (Tile).terrain | |||
Number | (Tile).id | |||
Boolean | (Tile):city_exists_within_city_radius | (may_be_on_center) | Deprecated in 2.3; use the next one instead. | |
Boolean | (Tile):city_exists_within_max_city_map | (may_be_on_center) | 2.3 | Returns true if there is a city within the maximum radius a city map can ever have in Freeciv (not necessarily possible in the current ruleset) -- currently within 5 tiles. |
City | (Tile):city | () | 2.3 | |
Number | (Tile):num_units | () | 2.3 | |
Number | (Tile):sq_distance | (Tile) | 2.3 | Returns squared distance between tiles. |
bool | (Tile):has_base | (name) | 2.4 | (name) may be either 'Fortress', 'Airbase', 'Buoy', or any base type defined in the ruleset. |
bool | (Tile):has_road | (name) | 2.5 | (name) may be either 'Road', 'Railroad', 'River', or any road type defined in the ruleset. |
bool | (Tile):has_extra | (name) | 2.6 | (name) may be either the name of a base or a road type. See (Tile):has_base() and (Tile):has_road(). |
Iterator (Unit) | (Tile):units_iterate | () | 2.3 | |
Iterator (Tile) | (Tile):square_iterate | (radius) | 2.3 | |
Iterator (Tile) | (Tile):circle_iterate | (sq_radius) | 2.3 | |
- | (Tile):create_base | (name, player) | 2.4 | See edit.create_base(). |
- | (Tile):create_road | (name) | 2.5 | See edit.create_road(). |
Boolean | (Tile):unleash_barbarians | () | 2.4 | See edit.unleash_barbarians(). |
- | (Tile):place_partisans | (player, count, sq_radius) | 2.4 | See edit.place_partisans(). |
- | (Tile):set_label | (labelstring) | 2.5 | See edit.tile_set_label(). |
Government
Type Government | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | (Government).id | |||
String | (Government):rule_name | () | 2.2 | |
String | (Government):name_translation | () | 2.2 |
Nation_Type
Type Nation_Type | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | (Nation_Type).id | |||
String | (Nation_Type):rule_name | () | 2.2 | |
String | (Nation_Type):name_translation | () | 2.2 | |
String | (Nation_Type):plural_translation | () | 2.2 |
Building_Type
Type Building_Type | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | (Building_Type).build_cost | |||
Number | (Building_Type).id | |||
Number | (Building_Type):build_shield_cost | () | Same information as build_cost. | |
Boolean | (Building_Type):is_wonder | () | ||
Boolean | (Building_Type):is_great_wonder | () | ||
Boolean | (Building_Type):is_small_wonder | () | ||
Boolean | (Building_Type):is_improvement | () | ||
String | (Building_Type):rule_name | () | 2.2 | |
String | (Building_Type):name_translation | () | 2.2 |
Unit_Type
Type Unit_Type | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | (Unit_Type).build_cost | |||
Number | (Unit_Type).id | |||
Boolean | (Unit_Type):has_flag | (flag_name) | ||
Boolean | (Unit_Type):has_role | (role_name) | ||
Boolean | (Unit_Type):can_exist_at_tile | (tile) | 2.3 | |
Number | (Unit_Type):build_shield_cost | () | Same information as build_cost. | |
String | (Unit_Type):rule_name | () | 2.2 | |
String | (Unit_Type):name_translation | () | 2.2 |
Tech_Type
Type Tech_Type | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | (Tech_Type).id | |||
String | (Tech_Type):rule_name | () | 2.2 | |
String | (Tech_Type):name_translation | () | 2.2 |
Terrain
Type Terrain | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | (Terrain).id | |||
String | (Terrain):rule_name | () | 2.2 | |
String | (Terrain):name_translation | () | 2.2 | |
String | (Terrain):class_name | () | 2.6 |
Disaster
Type Disaster | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | (Disaster).id | 2.5 | ||
String | (Disaster):rule_name | () | 2.5 | |
String | (Disaster):name_translation | () | 2.5 |
Achievement
Type Achievement | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | (Achievement).id | 2.6 | ||
String | (Achievement):rule_name | () | 2.6 | |
String | (Achivement):name_translation | () | 2.6 |
Connection
Type Connection | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | (Connection).id | 2.4 |
Nonexistent
Type Nonexistent | ||||
(return) type | function name / variable | arguments | ver | comments |
Boolean | (Nonexistent):exists | () | 2.2.1 |
Functions
Internationalization
String translation functions are used for localizable event scripts included with Freeciv (ruleset and tutorial). See Internationalization for what these functions do.
Functions Internationalization | ||||
(return) type | function name / variable | arguments | ver | comments |
String | _ | (msg) | ||
String | N_ | (msg) | ||
String | Q_ | (msg) | ||
String | PL_ | (singular, plural, n) |
Utilities
Functions Utilities | ||||
(return) type | function name / variable | arguments | ver | comments |
Number | random | (min, max) | Returns a random number using Freeciv's random number generator and random seeds. This allows reproducible games given the same initial conditions and inputs. Use this rather than Lua's math.random. | |
String | fc_version | () | 2.4 | |
- | error_log | (message) | 2.2 | Deprecated since 2.4. Use log.error instead. |
- | debug_log | (message) | 2.2 | Deprecated since 2.4. Use log.debug instead. |
Iterator (Player) | players_iterate | () | 2.3 | |
Iterator (Tile) | whole_map_iterate | () | 2.3 | |
Direction | str2direction | (str) | 2.4 | See direction.str2dir(). |
Actions
These unqualified function names are deprecated as of 2.4. Use the equivalent functions in the edit module instead.
Functions Action | ||||
(return) type | function name / variable | arguments | ver | comments |
Unit | create_unit | (player, tile, unit_type, veteran_level, homecity?, moves_left) | Deprecated in 2.4. Use edit.create_unit() instead. | |
Unit | create_unit_full | (player, tile, unit_type, veteran_level, homecity?, moves_left, hp_left, transport?) | 2.3 | Deprecated in 2.4. Use edit.create_unit_full() instead. |
- | create_base | (tile, name, player) | 2.2 | Deprecated in 2.4. Use edit.create_base() instead. |
- | create_city | (player, tile, name) | Deprecated in 2.4. Use edit.create_city() instead. | |
Player | create_player | (username, Nation_Type) | 2.3 | Deprecated in 2.4. Use edit.create_player() instead (although note that it has an extra argument). |
- | change_gold | (player, amount) | Deprecated in 2.4. Use edit.change_gold() instead. | |
Tech_Type | give_technology | (player, technology?, reason) | Deprecated in 2.4. Use edit.give_technology() instead. | |
Boolean | unleash_barbarians | (tile) | 2.2 | Deprecated in 2.4. Use edit.unleash_barbarians() instead. |
- | place_partisans | (tile, player, count, sq_radius) | 2.3 | Deprecated in 2.4. Use edit.place_partisans() instead. |
Events
Connect to an event signal using
signal.connect(signal_name, callback_name)
Currently, signals are only sent to ruleset scripts running on the server. The set of signals is defined in script_server.c (search for "script_server_signal_create").
Signals server | ||||
(return) type | function name / variable | arguments | ver | comments |
Boolean | turn_started | (Number turn, Number year) | ||
Boolean | unit_moved | (Unit unit, Tile src_tile, Tile dst_tile) | ||
Boolean | city_built | (City city) | ||
Boolean | city_growth | (City city, Number city_size) | ||
Boolean | unit_built | (Unit unit, City city) | ||
Boolean | building_built | (Building_Type type, City city) | ||
Boolean | city_lost | (City city, Player loser, Player winner) | 2.2 | |
Boolean | city_destroyed | (City city, Player loser, Player destroyer) | 2.2 | |
Boolean | unit_lost | (Unit unit, Player loser, String reason) | 2.2 | reason added in 2.4. Can be one of: "killed", "retired", "disbanded", "barb_unleash", "city_lost", "starved", "sold", "used", "executed", "eliminated", "editor", "nonnative_terr", "player_died", "armistice", "sdi", "detonated", "missile", "nuke", "hp_loss", "fuel", "stack_conflict", "bribed", "captured", "caught" |
Boolean | unit_cant_be_built | (Unit unit, City city, String reason) | reason may be: "need_tech", "pop_cost", "never", "unavailable" | |
Boolean | building_cant_be_built | (Building_Type type, City city, String reason) | reason may be: "pop_cost", "need_tech", "need_building", "need_special", "need_terrain", "need_government", "need_nation", "need_minsize", "need_ai_level", "need_terrainclass", "need_minyear", "never", "unavailable". | |
Boolean | tech_researched | (Tech_Type type, Player player, String source) | source may be: "researched", "traded", "stolen", "hut". | |
Boolean | hut_enter | (Unit unit) | ||
Boolean | map_generated | () | 2.5 | |
Boolean | disaster | (Disaster disaster, City city) | 2.5 | |
Boolean | achievement_gained | (Achievement achievement, Player gainer, Boolean first) | 2.6 | first indicated whether player is first one to reach the achievement. |
Script debugging
The following functions are helpful in debugging lua scripts:
Functions debugging | ||||
(return) type | function name / variable | arguments | ver | comments |
String | _freeciv_state_dump | () | Dump the state of user scalar variables to a Lua code string. | |
- | listenv | () | 2.4 | List all defined lua variables and functions. |
Examples
Simple example
The example code below should send the message 'Hello, World!' to all the players upon each new turn.
function hello_callback(turn, year) notify.all('Hello, World!') return false end signal.connect('turn_started', 'hello_callback')
Advanced Examples
Please read the Events Tutorial for examples of the most important concepts.
Part of Freeciv's ruleset is implemented in Lua. It can serve as an advanced example. Look at the files default/default.lua and default/script.lua in Freeciv's data directory. (You can also look at the current SVN version of these files)
Lua
The language used for Freeciv event scripts is Lua. As of Freeciv 2.2, we use Lua 5.1. In Freeciv 2.5 Lua is updated to 5.2.
Lua External Links:
Lua Builtins
Some Lua builtin functions and modules are also available in Freeciv (some functionality is intentionally left out by policy). It is not our intention to document Lua builtins here, but just to mention a selection of the useful parts.
Functions
Boolean, [Results] pcall(f, arg1, ...) Iterator (Key, Object) pairs(table) Iterator (Index, Object) ipairs(table)
Variables
Table _G -- The global environment (all variables) as a table.
Modules
math -- math.sqrt and other useful functions -- Important: never use math.random. Always use freeciv's random(min, max) string -- string matching table -- table.sort can sort an array-like table
Reference Links
The Scripting API is defined in
- .pkg files, and that must be the canonical reference to this API.
Links for the current development code (trunk) can be found at #Legend. For older/stable branches, see the following table. Please see these links for future updates, or if you suspect something in this Reference is wrong.
Version | scriptcore | server | events | client | fcdb | |||
---|---|---|---|---|---|---|---|---|
common_a | common_z | game | signal | |||||
2.5 | pkg | pkg | pkg | pkg | pkg | c | pkg | pkg |
2.4 | pkg | pkg | pkg | pkg | pkg | c | pkg | pkg |
2.3 | api.pkg | c | N/A | |||||
2.2 | api.pkg | c | ||||||
2.1 | api.pkg | c |