Batch component template properties

blueprint(set_component_properties_batch) writes several properties on component templates across several Blueprint assets. Each Blueprint is compiled once and saved once, even when several items address components in that same Blueprint. Saves target that Blueprint's package; unrelated dirty packages are not saved.

Use explicit items for a known set of assets:

{
  "action": "set_component_properties_batch",
  "items": [
    {
      "assetPath": "/Game/AI/BP_Guard",
      "componentName": "Combat",
      "properties": {
        "AttackMontage": "/Game/Animation/AM_Attack.AM_Attack",
        "BlockMontage": "/Game/Animation/AM_Block.AM_Block",
        "FinisherMontage": null
      }
    },
    {
      "assetPath": "/Game/AI/BP_Raider",
      "componentName": "Combat",
      "properties": {
        "AttackMontage": "/Game/Animation/AM_Attack.AM_Attack",
        "BlockMontage": "/Game/Animation/AM_Block.AM_Block"
      }
    }
  ],
  "dryRun": true
}

Alternatively, apply a shared map to Blueprint assets under a directory:

{
  "action": "set_component_properties_batch",
  "directory": "/Game/AI/Enemies",
  "classFilter": "/Script/Engine.Character",
  "componentName": "CharacterMovement",
  "properties": {
    "MaxWalkSpeed": 450,
    "bOrientRotationToMovement": true,
    "RotationRate.Yaw": 360
  },
  "recursive": true,
  "maxBlueprints": 200,
  "dryRun": false
}

items and directory selection are mutually exclusive. classFilter, componentName, properties and recursive at the top level belong to directory selection. classFilter accepts a native or Blueprint actor class and includes subclasses. recursive defaults to true. The Asset Registry's Blueprint assets are selected; maps and their level scripts are not enumerated.

maxBlueprints defaults to 200 and accepts 1 through 2000. Directory mode bounds the candidate count before loading and class/component filtering. Overflow refuses the call before any changes, rather than applying a truncated selection. Explicit mode accepts up to 10000 items, subject to the Blueprint limit.

Resolution and values

Component resolution is shared with set_component_property: own SCS templates, inherited SCS templates through the child's InheritableComponentHandler (ICH), then native default subobjects through the Blueprint's class default object. Use the SCS variable name, instance name, or native component property name such as CharacterMovement. An unambiguous component class name or class path is also accepted as a fallback by both setters. A class matching several components is refused; use a component name to disambiguate it.

Values use the single setter's parser: JSON numbers, booleans, strings, object references, structs, arrays, sets, maps and Unreal export text. null clears object/class/interface references. Dotted property names descend through structs, such as RotationRate.Yaw. Skeletal mesh aliases use SetSkeletalMeshAsset so the native skinned-asset state stays consistent.

Validation, results and saves

Every Blueprint's items are validated on transient component copies before its first edit. A failed property or missing explicit component refuses all items for that Blueprint. Other Blueprints can still succeed. A read-only or protected package is refused using the same write guard as the single setter, before any template changes or ICH creation. Dry runs use this guard too.

dryRun=true validates values without editing templates, creating ICH overrides, compiling or saving. It reports current values and proposedValues.

The response contains results in input order (sorted asset path order for directory selection), failed, skipped, blueprintsCompiled, blueprintsSaved and dryRun. Top-level success is false when any item fails. Each item includes index, assetPath, componentName, success, stage, saved and values. Resolved items also include previousValues, proposedValues, valuesText and inherited when available. values contains typed JSON read back from the template; valuesText contains Unreal export text. Readback after compilation resolves fresh templates, since compilation can replace the old class default object.

A missing or ambiguous component in directory mode is a selection skip with reason component_not_found_or_ambiguous; it does not fail the whole batch. Compiler, readback and save failures can leave in-memory edits. Results make those failures explicit with saved=false. There is no batch-wide transaction or automatic rollback, and successful Blueprints remain saved if another fails. Even an unchanged valid write compiles and saves its Blueprint once.

Rollback

When templates were edited, the result includes:

{
  "rollback": {
    "method": "set_blueprint_component_properties_batch",
    "payload": {
      "items": [
        {
          "assetPath": "/Game/AI/BP_Guard.BP_Guard",
          "componentName": "Combat",
          "properties": { "AttackMontage": "None" }
        }
      ],
      "maxBlueprints": 200
    }
  }
}

Flows replay rollback.method through the raw bridge task with rollback.payload. For a manual tool call, use blueprint, action=set_component_properties_batch, and the fields of rollback.payload as arguments. The payload includes touched items even when compilation or saving failed. It retains empty values, null references and structured map values. Dry runs and preflight refusals emit no rollback.

Rollback restores requested property values and saves them through the same batch action. It does not remove a newly created ICH override, restore a prior package dirty flag, reverse unrelated editor side effects, or restore disk contents independently of existing unsaved changes in the target package.