UE Editor Integration

Everything else in these docs happens at runtime: YAML is re-applied every session and never touches the assets on disk. This page covers the opposite workflow, for mod developers working inside the Unreal Editor. You apply your YAML packs directly onto the editor’s assets so the changes can be saved and become permanent.

Editor builds only (WITH_EDITOR). None of this exists in the packaged game or on dedicated servers. Players keep the runtime pipeline.

KDF.ApplyToAssets [PathFilter]

KDF.ApplyToAssets is a console command available only in editor builds. Run it with no arguments to sweep every scanned pack, or pass a path prefix to restrict the sweep to one branch of the content tree:

KDF.ApplyToAssets
KDF.ApplyToAssets /Game/FactoryGame/Recipes

It only touches documents that explicitly set type: cdo. It uses the same property-path parser and reflection operation engine (FKDFOpEngine::ApplyOp) as runtime, pointed at editor objects. Other document types (item, recipe, asset, …) are runtime concepts, and this command skips them.

For each cdo patch, the optional PathFilter restricts application to targets whose path starts with the filter. For example, /Game/FactoryGame/Recipes applies only recipe patches and leaves everything else untouched. The target field resolves the same way it does elsewhere in cdo patches: a class path resolves to that class’s CDO, and anything else is loaded as an object path.

Every modified package is marked dirty. For a Blueprint CDO, that is the generated class’s outer package, so the standard editor save flow (Save All or source-control checkout) persists the changes. Your YAML pack has effectively become a set of permanent asset edits. Afterwards, a summary line is logged with the number of ops applied, assets touched, and packages marked dirty.

Caution

This command is a narrow importer, not the runtime document dispatcher. It reads explicit target: paths and properties: only. It does not expand allAssetsOfClass or matchTag, and it does not reproduce applyToSubclasses, applyToSpawnedActors, or deferOneGameTick. Document conditions and include: ordering are also not evaluated here. Write editor-import patches with explicit targets and review the dirty packages before saving.

In-game editor property categories

The in-game /kdf editor groups reflected fields by their Unreal Category metadata. Categories are collapsed by default so large CDOs remain navigable. Reflected fields without CPF_Edit are placed in a separate Non-UPROPERTY / Internal category. Despite that UI label, they are still reflected FProperty fields; they simply lack the normal edit flag or category metadata. They remain available for inspection and editing through the same reflection operation pipeline.

CDO exports include these non-edit reflected fields as well.

Runtime-only defer flag

Set deferOneGameTick: true on a type: cdo patch when the base game initializes the target during startup and the patch must run after that initialization:

type: cdo
patches:
  - target: /Game/FactoryGame/Some/Class.Some_C
    deferOneGameTick: true
    properties:
      - path: SomeProperty
        value: 123

KDataForge waits for the matching world to enter BeginPlay, then applies the patch on the following game tick. The flag is deliberately a one-tick startup delay, not a general timer. KDF.ApplyToAssets ignores this flag and applies explicit targets immediately.

When to use which pipeline

Both pipelines share the same operation engine and property-path resolution. Target discovery, conditions, timing, and runtime modifiers differ as described above:

	Runtime (players, packs)	Editor (KDF.ApplyToAssets)
Changes live in	YAML, re-applied every session	The assets themselves, after saving
Reversible	Usually on next session. resourcenode destruction can persist in saves; recipe removal self-heals on a later load without the pack	Via source control / not saving
Audience	Players, pack authors	Mod developers cooking their own content
Document types	All (item, recipe, asset, cdo, …)	Explicitly typed cdo with explicit target: only
Diagnostics	debug: / KDF.Debug plus /kdf report	Command warnings and one summary log; no runtime patch report

See Resource Node removal before treating runtime YAML as reversible. Vanilla can retain destruction tombstones after that pack is removed.

Still open

Asset/image import into the editor (bringing type: asset files in as real texture assets) and editor-side UI polish (search/filter/sort over patchable assets) are not implemented yet.

Do not confuse this with the in-game editor (/kdf editor, opened from chat while playing). That is a separate, runtime-only tool for browsing and editing content live in a running session.