EventWML

From The Battle for Wesnoth Wiki
Revision as of 06:52, 1 March 2008 by Esr (talk | contribs)

[edit]WML Tags

A:

abilities, about, achievement, achievement_group, add_ai_behavior, advanced_preference, advancefrom, advancement, advances, affect_adjacent, ai, allied_with, allow_end_turn, allow_extra_recruit, allow_recruit, allow_undo, and, animate, animate_unit, animation, aspect, attack (replay, weapon), attack_anim, attacks (special, stats), avoid;

B:

base_unit, background_layer, berserk, binary_path, break, brush;

C:

campaign, cancel_action, candidate_action, capture_village, case, chance_to_hit, change_theme, chat, checkbox, choice, choose, clear_global_variable, clear_menu_item, clear_variable, color_adjust, color_palette, color_range, command (action, replay), continue, core, credits_group, criteria;

D:

damage, damage_type, death, deaths, default, defend, defends, defense, delay, deprecated_message, destination, difficulty, disable, disallow_end_turn, disallow_extra_recruit, disallow_recruit, do, do_command, drains, draw_weapon_anim;

E:

editor_group, editor_music, editor_times, effect, else (action, animation), elseif, endlevel, end_turn (action, replay), enemy_of, engine, entry (credits, options), era, event, experimental_filter_ability, experimental_filter_ability_active, experimental_filter_specials, extra_anim;

F:

facet, facing, fake_unit, false, feedback, female, filter (concept, event), filter_adjacent, filter_adjacent_location, filter_attack, filter_attacker, filter_base_value, filter_condition, filter_defender, filter_enemy, filter_location, filter_opponent, filter_own, filter_owner, filter_radius, filter_recall, filter_second, filter_second_attack, filter_self, filter_side, filter_student, filter_vision, filter_weapon, filter_wml, find_path, fire_event, firststrike, floating_text, fonts, for, foreach, found_item, frame;

G:

game_config, get_global_variable, goal, gold, gold_carryover;

H:

harm_unit, has_ally, has_attack, has_unit, has_achievement, have_location, have_unit, heal_on_hit, heal_unit, healed_anim, healing_anim, heals, hide_help, hide_unit, hides;

I:

idle_anim, if (action, animation, intro), illuminates, image (intro, terrain), init_side, insert_tag, inspect, item, item_group;

J:

jamming_costs, join;

K:

kill, killed;

L:

label, language, leader, leader_goal, leadership, leading_anim, levelin_anim, levelout_anim, lift_fog, limit, literal, load_resource, locale, lock_view, lua;

M:

male, menu_item, message, micro_ai, missile_frame, modification, modifications, modify_ai, modify_side, modify_turns, modify_unit, modify_unit_type, move, move_unit, move_unit_fake, move_units_fake, movement_anim, movement costs, movetype, multiplayer, multiplayer_side, music;

N:

not, note;

O:

object, objective, objectives, on_undo, open_help, option, options, or;

P:

part, petrifies, petrify, place_shroud, plague, poison, post_movement_anim, pre_movement_anim, primary_attack, primary_unit, print, progress_achievement, put_to_recall_list;

R:

race, random_placement, recall (action, replay), recalls, recruit, recruit_anim, recruiting_anim, recruits, redraw, regenerate, remove_event, remove_item, remove_object, remove_shroud, remove_sound_source, remove_time_area, remove_trait, remove_unit_overlay, repeat, replace_map, replace_schedule, replay, replay_start, reset_fog, resistance (ability, unit), resistance_defaults, resolution, resource, return, role, rule;

S:

save, scenario, screen_fade, scroll, scroll_to, scroll_to_unit, secondary_attack, secondary_unit, section, select_unit, sequence, set_achievement, set_extra_recruit, set_global_variable, set_menu_item, set_recruit, set_specials, set_variable, set_variables, sheath_weapon_anim, show_if (message, objective, set_menu_item), show_objectives, side, skirmisher, slider, slow, snapshot, sound, sound_source, source (replay, teleport), special_note, specials, split, stage, standing_anim, statistics, status, store_gold, store_items, store_locations, store_map_dimensions, store_reachable_locations, store_relative_direction, store_side, store_starting_location, store_time_of_day, store_turns, store_unit, store_unit_defense, store_unit_defense_on, store_unit_type, store_unit_type_ids, store_villages, story, swarm, sub_achievement, switch, sync_variable;

T:

target, team, teleport (ability, action), teleport_anim, terrain, terrain_defaults, terrain_graphics, terrain_mask, terrain_type, test, test_condition, test_do_attack_by_id, text_input, textdomain, theme, then, tile, time, time_area, topic, toplevel, trait, transform_unit, traveler, true, tunnel;

U:

unhide_unit, unit (action, scenario), unit_overlay, unit_type, unit_worth, units, unlock_view, unpetrify, unstore_unit, unsynced;

V:

value, variable, variables, variant, variation, victory_anim, village, vision_costs, volume;

W:

while, wml_message, wml_schema;

Z:

zoom;

The [event] tag

This tag is a subtag of [scenario] (or [unit] - see event, UnitWML) which is used to describe a set of actions which trigger at a certain point in the scenario.

Keys and tags that describe when the event should trigger:

  • name: this is not like a normal 'name' key. It is a basic description of when the event will trigger.
  • prestart: the event is triggered before a scenario 'starts' -- before anything is shown on the screen at all. You can use this event to set up things like village ownership. For things displayed on-screen such as character dialog, use start'.
  • start: this event triggers after the map is shown but before the scenario begins
  • new turn: this event triggers whenever the last player ends their turn. See also first_time_only=no. When the last player ends their turn, before any events of this type trigger, the value of the WML variable turn_number is set to the number of the turn that is beginning.
  • side turn: this event triggers when a side is about to start its turn. Before events of this type trigger, the value of the WML variable side_number is set to the number of the side of the player about to take their turn. This is before any healing takes place for that side, before calculating income, and before restoring unit movement and status.
  • turn refresh: this event triggers just before a side is taking control after healing, calculating income, and restoring unit movement and status.
  • turn X: (for X some number) this event triggers at the start of turn X. X cannot be 1.
  • time over: this event triggers on turn turns. (turns is specified in [scenario])
  • enemies defeated: this event triggers when all units with canrecruit=yes (i.e. all leaders) not allied with side 1 are killed.
  • victory: in this scenario, any tag of the form [endlevel] result=victory [/endlevel] will be automatically preceded by all actions in this tag. It helps debugging if the victory event allows you to safely advance to any of the possible next maps after using the ":n" command. Scenarios where key units are picked up before the victory, or where some action chosen earlier determines which map to advance to, make it hard to quickly test scenarios in a campaign. (See also [endlevel], DirectActionsWML)
  • defeat: in this scenario, any tag of the form [endlevel] result=defeat [/endlevel] will be automatically preceded by all actions in this tag. (See also [endlevel], DirectActionsWML)
  • ai turn: is triggered just before the AI is invoked for a side. This is called after side turn, and thus the WML variable side_number still holds the number of this side.

Filters can be applied to the following event triggers (see FilterWML; see also below). The actions specified in the event tag will be executed only if the filter returns true. These event triggers are all actions by units (moveto, attack) or things that happen to units (recruit, advance). When one of these events is triggered, the position of the active unit (referred to as primary_unit) is stored in the variables x1 and y1 and the position of any unit that primary_unit does something to is stored in the variables x2 and y2 (this unit is referred to as secondary_unit below). These units are also stored in the variables 'unit' and 'second_unit' as if they had been stored using the [store_unit] tag. see SingleUnitWML

  • moveto': triggers after primary_unit moves. Typically this is used when primary_unit gets to a particular location and a filter for the location of primary_unit is included; remember that this is the location that primary_unit lands on, not the location it started on or any location it travels on.
  • sighted': this event triggers when primary_unit moves to a location where secondary_unit is in primary_units sight range. Works only in shroud or fog.
  • attack: this event triggers when primary_unit attacks secondary_unit.
  • attacker_hits: this event triggers when the attacker (primary_unit) hits the defender (secondary_unit).
  • attacker_misses: same as attacker_hits, but is triggered when the attacker misses.
  • defender_hits: this event triggers when the attacker (primary_unit) is hit in retaliation by the defender (secondary_unit).
  • defender_misses: same as defender_hits, but is triggered when the defender misses.
  • attack_end: is similar to attack, but is instead triggered after the fight, not before. Note that if either unit is killed during the fight, this event triggers before any die events.
  • stone: this event triggers when primary_unit is hit by an attack with the 'stones' ability (See stones, AbilitiesWML) by secondary_unit (secondary_unit is the unit with the 'stones' ability.)
  • last breath: this event triggers when primary_unit is killed by secondary_unit, but before the death animation is triggered.
  • die: this event triggers when primary_unit is killed by secondary_unit.
  • capture: this event triggers when primary_unit captures a village. The village may have been previously neutral, or previously owned by another side; merely moving into your own villages does not constitute a capture.
  • recruit: this event triggers when primary_unit is recruited or recalled. (That is, when a unit is recruited or recalled, it will trigger this event and this event's filter will filter that unit.)
  • prerecruit: this event triggers when primary_unit is recruited, but before it is displayed.
  • advance: this event triggers just before primary_unit is going to advance to another unit.
  • post_advance: this event triggers just after primary_unit has advanced to another unit.
  • select: triggers when a unit is selected. Note: in networked multiplayer, these events are only executed by the client on which the event is triggered, leading to out of sync errors if you modify the game state in the event.
  • menu item X: triggers when a WML menu item with id=X is selected. Note: if the menu item has a [command], this event may be executed before or after the command; there is no guarantee.


An [allow_undo] tag anywhere within a moveto event will cancel any lack of undo functionality the event would have caused. Note that undo functionality will only move the unit back to its former location; it will not other changes to the game caused by the event. Thus it is up to the scenario designer to use this tag correctly.

Primary_unit can be referred to as unit and Secondary_unit can be referred to as second_unit in [message] tags. For example: 

[event]
name=die
  [message]
  speaker=second_unit
  message="Hahaha, I finally killed you!"
  [/message]

  [message]
  speaker=unit
  message="It's not over yet! I'll come back to haunt you!"
  [/message]
[/event]

These keys and tags are more complex ways to filter when an event should trigger:

  • first_time_only: whether the event should be removed from the scenario after it is triggered. Default is yes.
  • [filter]: the event will only trigger if primary_unit matches this filter.
    • standard unit filter: attributes for [filter] are described in FilterWML
  • [filter_second]: is like [filter], but for secondary_unit.
    • standard unit filter
  • [special_filter] and [special_filter_second]: can be used to set some additional filtering criteria for primary_unit and secondary_unit that are not generally available in a standard unit filter. Can be used in events attack, attacker_hits, attacker_misses, defender_hits, defender_misses and attack_end.
    • weapon: the name of the weapon used.
    • terrain: the code for the terrain the unit is on.

Actions triggered by [event]

After the trigger conditions have been met, all action tags within the [event] tag are executed in the order they are written in.

There are 3 main types of actions:

Several actions use standard filters to find out which units to execute the command on. These are denoted by the phrases "standard unit filter" and "standard location filter".

Nested events

There is 1 special type of action: event creation. By placing an [event] tag inside another [event] tag, the nested event is created when the nested event is encountered (when executing the contents of the event). For example, you could create a portal that opens on turn 10. The outer event executes on turn 10, creating the nested moveto event, which executes when a player steps on a certain spot. An equivalent way of doing this would be to a single moveto event with an if statement to check for turn number, but using nested [event] tags is a simple and elegant way to accomplish more complex tasks without resorting to excessive if statements.

Example: 

[event]
    name=turn 10

    [event]
        name=moveto

        [filter]
            x,y=5,8
        [/filter]

        # moving to 5,8 will trigger this event only on turn 10 and after
    [/event]
[/event]

See Also

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