Using the “modify”-Preset

MizEdit’s modify DSL (Domain Specific Language) lets you search and modify Lua tables inside DCS .miz files.

A .miz file is a ZIP archive containing three Lua table files:

File	Contents
`mission`	Units, routes, weather, triggers, coalition data — the main mission
`options`	Mission options (overrides the player’s `options.lua`)
`warehouses`	Airport warehouse data and dynamic spawn configuration

MizEdit unpacks the .miz, amends these Lua tables, and repacks into a new .miz file.

DSL Overview

Every modify block follows this structure:

# config/presets.yaml
PresetName:
  modify:
    file: mission          # which Lua file to modify: mission | options | warehouses
    variables: ...         # optional: extract or define variables
    if: ...                # optional: condition that must be true
    for-each: <path>       # required: path to elements to iterate
    where: ...             # optional: filter on the reference element
    select: <path>         # optional: navigate deeper to the element to change
    replace: ...           # modify existing values
    delete: ...            # remove elements
    insert: ...            # add new keys/values
    merge: ...             # merge two Lua tables
    run: <python.func>     # call a Python function for complex logic
    debug: true            # optional: verbose logging

Paths navigate the Lua table tree from root to leaf:

Syntax	Meaning
`/node`	Descend into a named key
`*`	Iterate all elements in a list or table
`[x]`	Select the n-th element from a Lua list (1-based) or a specific key from a table
`[x,y]`	Select multiple elements
`$'...'`	Evaluate the content as a Python expression (returns a boolean for filtering, or a value for replacement)
`'{var}'`	Substitute a previously defined variable’s value

Important on indexing: Lua lists are 1-based, so [1] is the first element. However, when accessing data via Python expressions (inside $'...' or reference), use Python 0-based indexing: reference[units][0].

Finding Elements

`for-each` — sets the iteration and the reference element

for-each defines which elements to iterate over. The matched element becomes the reference element — the context you work with.

for-each: coalition/blue/country/*/ship/group/*/units/$'{type}' in ['CVN_71','CVN_72','CVN_73','CVN_74','CVN_75']

This walks the mission tree and selects every individual carrier unit matching the type list. The reference element is each unit.

`where` — filters without changing the reference

where filters which reference elements to process, but does NOT change what the reference points to.

for-each: coalition/blue/country/*/ship/group/*
where: units/$'{type}' in ['CVN_71','CVN_72','CVN_73','CVN_74','CVN_75']

This iterates all groups, but only processes groups containing a matching carrier. The reference element is each group (not the unit). This matters when you need to modify group-level data like routes.

Rule: Use for-each alone when you want to modify the iterated elements directly. Add where when you need to filter by a child property but work on the parent.

`select` — navigates deeper to the target

select navigates from the reference element to the specific sub-element to modify. The reference stays the same.

for-each: coalition/blue/country/*/ship/group/*
where: units/$'{type}' in ['CVN_71','CVN_72','CVN_73','CN_74','CVN_75']
select: route/points/*/task/params/tasks/$'{id}' == 'WrappedAction'/params/action/$'{id}' == 'ActivateBeacon'/params

This finds blue carrier groups, then drills into their route tasks to find TACAN beacon parameters.

Modification Operations

`replace` — overwrite values

Simple replacement:

replace:
  frequency: 371000000
  modeChannel: X

Conditional replacement (switch/case): When a replace value is a mapping, each key is a Python expression. The first expression that evaluates to True determines the value:

replace:
  frequency:
    $'{reference[units][0][type]}'[-2:] == '72': 1158000000
    $'{reference[units][0][type]}'[-2:] == '73': 1160000000

`delete` — remove elements

delete: $'{type}' == 'FA-18C_hornet'

`insert` — add new keys/values

Use insert when the target key doesn’t exist yet:

insert:
  Radio:
    - channels:
        - 243

`merge` — combine Lua tables

Merges two parts of a mission file together, e.g., merging neutral country data into blue:

merge:
  source: coalition/neutral
  target: coalition/blue

Built-in Variables

The following variables are available in all modify blocks:

Variable	Description
`{reference}`	The current reference element (set by `for-each`). Access properties like `{reference[units][0][type]}`. Uses Python 0-based indexing.
`{type}`	The type name of the current element (when iterating units)

Custom Variables

Extract values from the mission or define your own:

variables:
  theatre: theatre                          # extract from mission
  temperature: weather/season/temperature   # extract nested value
  speed: 40                                 # fixed value
  rand: '$random.randint(1, 10)'            # Python random
  mylist: '$list(range(1, {rand}))'         # use other variables

Reference variables with {variablename} in paths and expressions.

Conditions

Run the modification only when a condition is met:

variables:
  start_time: start_time
  theatre: theatre
if: ${start_time} > 20000 and '{theatre}' == 'Caucasus'

Python Functions

For complex logic, call a Python function:

variables:
  wind: weather/wind/atGround
for-each: coalition/*/country/*/ship/group/*
where: units/$'{type}' in ['CVN_71','CVN_72','CVN_73','CVN_74','CVN_75', "Stennis", "LHA_Tarawa"]
run: core.utils.mizedit.relocate_carrier

The function receives three arguments:

Parameter	Description
`data`	The selected element
`reference`	The reference element
`kwargs`	All defined variables

def my_function(data: dict, reference: dict, **kwargs) -> dict:
    # modify data in place or return a replacement dict
    return data

See the DCSServerBot source for available built-in functions.

Debugging

Set debug: true to enable verbose logging. The log shows which elements were matched and what changes were made. Check the DCSServerBot log file for output.

Examples

Example 1: Change carrier frequencies (simple replacement)

Select every blue carrier unit and set its frequency based on type:

# config/presets.yaml
SetCarrierFreqs:
  modify:
    file: mission
    for-each: coalition/blue/country/*/ship/group/*/units/$'{type}' in ['CVN_71','CVN_72','CVN_73','CVN_74','CVN_75']
    replace:
      frequency:
        "$'{type}' == 'CVN_71'": 371000000
        "$'{type}' == 'CVN_72'": 372000000
        "$'{type}' == 'CVN_73'": 373000000
        "$'{type}' == 'CVN_74'": 374000000
        "$'{type}' == 'CVN_75'": 375000000

Shorter version using a Python calculation:

# config/presets.yaml
SetCarrierFreqs:
  modify:
    file: mission
    for-each: coalition/blue/country/*/ship/group/*/units/$'{type}' in ['CVN_71','CVN_72','CVN_73','CVN_74','CVN_75']
    replace:
      frequency: $int('3' + '{type}'[-2:] + '000000')

Example 2: Change TACAN frequencies (deep navigation with `where` + `select`)

TACAN data is nested inside the group’s route, not on the unit itself. We use for-each to iterate groups, where to filter for carrier groups, and select to reach the beacon parameters:

# config/presets.yaml
SetTACAN:
  modify:
    file: mission
    for-each: coalition/blue/country/*/ship/group/*
    where: units/$'{type}' in ['CVN_71','CVN_72','CVN_73','CVN_74','CVN_75']
    select: route/points/*/task/params/tasks/$'{id}' == 'WrappedAction'/params/action/$'{id}' == 'ActivateBeacon'/params
    replace:
      modeChannel: X
      channel: $'{reference[units][0][type]}'[-2:]
      frequency:
        $'{reference[units][0][type]}'[-2:] == '72': 1158000000
        $'{reference[units][0][type]}'[-2:] == '73': 1160000000

Here {reference} points to the group (from for-each), so {reference[units][0][type]} gets the first unit’s type name. The [-2:] slice extracts the carrier number (e.g. “72” from “CVN_72”).

Example 3: Set radio presets (with `insert`)

Set the first radio channel of all blue F-14Bs. Uses insert to add the Radio key if it doesn’t exist:

# config/presets.yaml
ChangeRadios:
  modify:
    file: mission
    for-each: coalition/blue/country/*/plane/group/*/units/$'{type}' in ['F-14B']
    select: Radio/[1]/channels
    replace:
      1: 243
    insert:
      Radio:
        - channels:
            - 243

Example 4: Delete all Hornets (with `delete`)

# config/presets.yaml
DeleteAllHornets:
  modify:
    file: mission
    for-each: coalition/[blue,red]/country/*/plane/group/*/units
    delete: $'{type}' == 'FA-18C_hornet'

Example 5: Enable dynamic cargo on blue warehouses (different target file)

# config/presets.yaml
EnableDynamicCargo:
  modify:
    file: warehouses
    debug: true
    for-each: airports/*/$'{coalition}' == 'BLUE'
    replace:
      dynamicCargo: true

Example 6: Search path walkthrough

The path coalition/[blue,red]/country/*/ship/group/*/units/$'{type}' in ['CVN_71'..'CVN_75'] walks the tree:

|_ coalition
   |_ blue
      |_ country
         |_ ... all countries ...
            |_ ship
               |_ group
                  |_ ... all groups ...
                      |_ units
                            |_ elements where ["type"] is one of ['CVN_71'..'CVN_75']
   |_ red
      |_ ... same structure ...

Using the “modify”-Preset

DSL Overview

Path Navigation

Finding Elements

for-each — sets the iteration and the reference element

where — filters without changing the reference

select — navigates deeper to the target