InternalActionsWML

Internal actions

Internal actions are actions that WML uses internally that do not directly affect gameplay, for example storing a variable.

The internal actions [if], [while], and [event] describe when/whether sets of actions should be executed.

[if]

Executes different sets of actions based on whether the conditions described in the condition tags are true or not.

Condition tags:

[have_unit]: a unit passing this filter with >0 HP exists
- StandardUnitFilter (almost... Note: does not check for matching units in the recall list)

[have_location]: a location passing this filter exists
- StandardLocationFilter

[and]: If an [and] is present, all must evaluate to true in order for the [if] to evaluate true. Useful as a bracket for complex conditions, but not strictly necessary.
- condition tags as in [if]: if these evaluate to true, [and] evaluates to true.

[or]: If an [or] is present, one must evaluate to true in order for the [if] to evaluate true. (Example)
- condition tags as in [if]: if these evaluate to true, [or] evaluates to true.

[not]: If a [not] is present, none must evaluate to true in order for the [if] to evaluate true.
- condition tags as in [if]: if these evaluate to true, [not] evaluates to false.

[and],[or],[not]: all top-level filters will support in-order conditional handling of and, or, and not. One important thing to remember is, if you have multiple [or]s, you should not wrap your first conditional statement into an [or] block.

[variable]: tests something about the value of a WML variable (see VariablesWML)
- name: the name of the variable to test the value of
  Only one of the following keys should be used for comparing the value of the variable to another value:
- equals: $name is equal (string wise) to this
- not_equals: $name is not equal to this
- greater_than: $name is numerically greater than this
- less_than: $name is less than this
- greater_than_equal_to: $name is not less than this
- less_than_equal_to: $name is not greater than this
- numerical_not_equals: $name is greater than or less than this
- numerical_equals: $name is not greater than or less than this
- boolean_equals: $name has the same boolean value (e.g. off, false, 0, no)
- contains: $name contains this string
- Template:DevFeature boolean_not_equals: $name has not the same boolean value. Strictly a syntactic shortcut for the following syntax that served its absence in 1.4:

 [not]
   [variable]
     name=...
     boolean_equals=...
   [/variable]
 [/not]

After condition tags:

[then]: contains a set of action tags which should be executed if all conditions are true, or all conditions in any single [or] are true
[else]: contains a set of action tags which should be executed if any condition is false, and all [or] tags are false

[switch] Template:DevFeature

Executes different sets of action based ont the value of a variable.

 [switch]
    variable=foo
    [case]
       value="A"
       ... WML if foo=A ...
    [/case]
    [case]
       value="B"
       ... WML if foo=B ...
    [/case]
    [else]
       ... WML if not foo=A nor foo=B ...
    [/else]
 [/switch]

variable: variable to check.
[case]: Case block. Contains:
- value: the value to test the variable against.
- the action WML to execute if the variable matches the value (rest of the block).
[else]: Block of action WML to execute if no [case] block matches.

[while]

Executes commands if all conditions are true. Continues to execute them until a condition is not true.

Executes a maximum of 1024 iterations per invocation. Condition tags are the same as for [if]

After condition tags:

[do]: contains actions that should be executed repeatedly until some condition is false.

The [while] tag is useful for iterating over an array. An array is a list of values. The numberth value in the array array is stored in the WML variable array[number]. Note that if number is the value of the variable variable, the expression $array[$variable] will return the numberth value in array. The macros 'FOREACH' and 'NEXT' (UtilWML) can be used to iterate over an array; i.e. run a set of actions once per element of the array.

{FOREACH}

If you wish to use a "for-each" iteration format (useful for example when you want to do an iteration for each row in a table) you can use the FOREACH and NEXT prededined macros.

{REPEAT}

You can use the REPEAT macro to perform a quick iteration for a number of times you specify.

[event]

This adds a new event to the scenario. The event is in the normal format for an [event] tag (See EventWML). This is useful if you want an event that can only be triggered when a prior event is fulfilled

These tags describe actions that affect the values of WML variables (see VariablesWML for information on WML variables, and UtilWML for convenient macro shortcuts for some of these):

[set_variable]: manipulates a WML variable. (Note: You can use the VARIABLE predefined macro to achieve the same result in a shorter format)
- name: the name of the variable to manipulate
- value: set the variable to the given value (can be numeric or string). This only interprets dollars signs if it is the very first character, and then the entire value must be a simple variable name. (in 1.3.2, has the same effect as format. Use literal for no substitution)
- literal: set the variable to the given value (can be numeric or string). This does not interpret any dollars signs.
- format: set the variable to the given value. Interprets the dollar sign to a higher degree than most actions. (see VariablesWML)
- to_variable: Fully processes its value as in format, and then gets the variable with that name.
- add: add the given amount to the variable. To subtract, add a negative number.
- multiply: multiply the variable by the given number. To divide, multiply by the inverse eg: 4/2 = 4 * 1/2 = 4 * 0.5. To negate, multiply by -1. The result is an integer.
- divide: divide the variable by the given number. The result is an integer.
- modulo: returns the remainder of an integer division. Both variables need to be an integer, the result is also an integer. eg 5 % 2 = 1.
- random: the variable will be randomly set.
  You may provide a comma separated list of possibilities, e.g. 'random=Bob,Bill,Bella'.
  You may provide a range of numbers (integers), e.g. 'random=3..5'.
  You may combine these, e.g. 'random=100,1..9', in which case there would be 1/10th chance of getting 100, just like for each of 1 to 9. Dollars signs are only normally interpreted here, so it is harder to have a dynamically determined range. You would need to create the random-string with format.
- rand: does the same as random, but has better MP support. See BuildingMultiplayerExamples for more info on the MP case. It is highly recommended that you use this feature for randomization.
- time=stamp: Retrieves a timestamp in milliseconds since wesnoth was started, can be used as timing aid. Don't try to use this as random value in MP since it will cause an OOS.
- Template:DevFeature string_length: Retrieves the length in characters of the string passed as this attribute's value; such string is parsed and variable substitution applied automatically (see VariablesWML for details).
- Template:DevFeature [join] joins an array of strings to a textual list
  - variable: name of the array
  - key: array[$i].key to look for the strings
  - separator: separator to connect the elements
  - remove_empty: wether to ignore empty elements

Template:DevFeature [set_variables]: manipulates a WML array
- name: the name of the container to manipulate
- mode: one of the following values:
  - replace: will clean the array name and replace it with given data
  - append: will append given data to the current array
  - merge: will merge in the given data into name
- to_variable: data will be set to the given array
- [value]: the WML inside the [value] tags will be stored in data, variables will be interpolated directly, use $| in order to escape the $ sign, you can store arrays of WML by supplying multiple [value] tags
- [literal]: same as [value], but variables will not be substituted, [literal] and [value] can not be used at once
- [split] splits a textual list into an array which will then be set to data
  - list: textual list to split
  - key: array[$i].key to put the elements in
  - separator: separator to separate the elements
  - remove_empty: wether to ignore empty elements

[store_unit]: stores details about units into game variables.
Common usage is to manipulate a unit by using [store_unit] to store it into a variable, followed by manipulation of the variable, and then [unstore_unit] to re-create the unit with the modified variables.
Note: stored units also exist on the field, and modifying the stored variable will not automatically change the stats of the units. You need to use [unstore_unit]. See also [unstore_unit], DirectActionsWML, and FOREACH, UtilWML
- [filter]: StandardUnitFilter all units matching this filter will be stored. If there are multiple units, they will be stored into an array of variables.
- variable: the name of the variable into which to store the unit(s)
- mode: defaults to always_clear, which clears the variable, whether or not a match is found. If mode is set to replace, the variable will only be cleared if a match is found. If mode is set to append, the variable will not be cleared.
- kill: if 'yes' the units that are stored will be removed from play. This is useful for instance to remove access to a player's recall list, with the intent to restore the recall list later.

When a unit is stored, the following values may be manipulated with [set_variable]

description
experience
facing
gender
canrecruit
overlays
goto_x
goto_y
hitpoints
moves
resting
side
type
unrenamable
upkeep
user_description
x
y
[variables]
[status]
[modifications]

Variables, status, and modifications are children of the stored unit variable. Example:

[set_variable]
name=unit_store.status.poisoned
value=yes
[/set_variable]

All keys and tags in the unit definition may be manipulated, including some others. Here is a sample list. If you have a doubt about what keys are valid or what the valid value range is for each key, code a [store_unit] event, save the game, and examine what keys are in the file.

advanceto
alignment
alpha
attacks_left
canrecruit
controller
cost
description
experience
facing
flying
fog
gender
get_hit_sound
gold
goto_x
goto_y
hitpoints
id
image
image_defensive
income
language_name (same as the name key in the unit config)
level
max_attacks
max_experience
max_hitpoints
max_moves
movement
movement_type
moves
race
resting
shroud
side
team_name
type
unit_description
unrenamable
usage
value
x
y
zoc
[advancement]
[/advancement]
[movement_costs]
[/movement_costs]
[defense]
[/defense]
[resistance]
[/resistance]
[variables]
[/variables]
[status]
[/status]
[attack]
[/attack]
[modifications_description]
[/modifications_description]
[modifications]
[/modifications]

[store_starting_location]: Stores the starting location of a side's leader in a variable. The variable is a composite type which will have members 'x', 'y', and 'terrain' (the terrain type for a starting location is always 'K' unless it has been changed)
- side: the side whose starting location is to be stored
- variable: (default='location'): the name of the variable to store the location in
[store_locations]: Stores a series of locations that pass certain criteria into an array. Each member of the array has members 'x' and 'y' (the position) and 'terrain' (the terrain type).
- StandardLocationFilter: a location or location range which specifies the locations to store. You must specify this or no locations will be stored.
- variable: the name of the variable (array) into which to store the locations
- terrain: a comma-sperated list of terrain codes. (See TerrainCodesWML for possible values.) If present, locations will only be chosen if the code for the terrain type of that location is listed.
- radius: if present, any locations which are within radius hexes of the location filter will also be stored
- [filter]: StandardUnitFilter only locations with units on them that match the filter will be stored. Use a blank filter to only store locations with units.
[store_villages]: Stores a series of locations of villages that pass certain criteria into an array. Each member of the array has members 'x' and 'y' (the position) and 'terrain' (the terrain type).
- owner_side: a side number. If present, only villages owned by this side will be choosen. If owner_side=0, store the unowned villages.
- variable: the name of the variable (array) into which to store the locations
- terrain: a series of terrain characters. (See TerrainLettersWML for possible values.) If present, villages will only be chosen if the terrain code of the terrain type of that location is listed. You may give a comma separated list of terrains.
- side: (default=1) the side for which the gold should be stored
- variable: (default='gold') the name of the variable to store the gold in
[store_side]: stores information about a certain side in a variable. The variable will contain the member variables 'name', 'team_name', 'gold' and 'income', 'fog', 'shroud', 'user_team_name', 'colour', 'controller', 'village_gold' and 'recruit'.)
- side: the side whose information should be stored
- variable: the name of the variable to store the information in
[clear_variable]: This will delete the given variable or array. This is good to use to clean up the set of variables -- e.g. a well-behaved scenario will delete any variables that shouldn't be kept for the next scenario before the end of the scenario.
Tags and variables of stored units can also be cleared, meaning that [trait]s and [object]s, for example, can be removed.
- name: the name of the variable to clear.
[role]: tries to find a unit to assign a role to.
This is useful if you want to choose a non-major character to say some things during the game. Once a role is assigned, you can use role= in a unit filter to identify the unit with that role (See FilterWML).
However, there is no guarantee that roles will ever be assigned. You can use [have_unit] (see [if]) to see whether a role was assigned. This tag uses a StandardUnitFilter with the modification to order the search by type, mark only the first unit found with the role, and the role attribute is not used in the search. If for some reason you want to search for units that have or don't have existing roles, you can use one or more [not] filters. The will check recall lists in addition to units on the map. In normal use, you will probably want to include a side attribute to force the unit to be on a particular side.
- role: the value to store as the unit's role. This role is not used in the StandardUnitFilter when doing the search for the unit to assign this role to.
- type: a comma-separated list of possible types the unit can be. If any types are given, then units will be searched by type in the order listed. If no type is given, then no particular order with respect to type is guaranteed.
Template:DevFeature [store_map_dimensions]: Stores the map dimensions in a variable.
- variable: the name of the variable where the values will be saved into. If it is skipped, a variable 'map_size' is used, and its contents overridden, if they existed already. The result is a container variable, with members width and height.

InternalActionsWML

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