[Bug]: Studio Data Importer — Advanced Many-to-Many relation fields cannot be selected as mapping target #536

Affected Version

2026.2 (pimcore/data-importer v2026.2.4) — the affected code is unchanged on the current 2026.2 branch.

Affected capability

DataHub (Data Importer, Studio UI — mapping step, data target)

Steps to reproduce

1. Have a data object class with an Advanced Many-to-Many Object Relation field (e.g. components).
2. Open a Data Objects importer configuration in Studio for that class and run a preview import.
3. Add a mapping whose transformation pipeline results in a dataObjectArray (e.g. Load Data Object followed by As Array).
4. In the advanced mapping modal, set the data target type to Many-to-Many Relation and open the field select.

Actual Behavior

The field select only lists manyToManyRelation / manyToManyObjectRelation fields. Advanced Many-to-Many (Object) Relation fields are never offered — with any data target type — so they cannot be used as an import target from Studio at all, even though the ManyToManyRelation data target explicitly supports them on the backend.

Expected Behavior

With the Many-to-Many Relation data target, the field select also lists advancedManyToManyRelation and advancedManyToManyObjectRelation fields, like the classic admin UI did.

Cause & fix

The backend already supports this: class-attributes takes a loadAdvancedRelations flag, and TransformationDataTypeService::getPimcoreDataTypes() then swaps dataObjectArray / assetArray for their advanced variants. The Studio UI never sends that flag, and it caches class attributes per transformation result type only, regardless of the data target type.

A pull request with the fix is attached: pimcore/data-importer#702