Bonsai Property Set Management

Version: Bonsai v0.8.x | IfcOpenShell v0.8+ | Blender 4.2.0+ | Python 3.11 Module path: bonsai.bim.module.pset, bonsai.bim.module.pset_template, bonsai.bim.module.qto IFC API: ifcopenshell.api.pset, ifcopenshell.api.pset_template

Critical Warnings

1. ALWAYS use ifcopenshell.api.run("pset.edit_pset", ...) to modify properties. NEVER set prop.NominalValue directly — it bypasses template validation, type inference, and owner history.
2. ALWAYS pass product (singular) to pset.add_pset and pset.add_qto. Pass products (list) to pset.assign_pset.
3. NEVER use the Pset_ or Qto_ prefix for custom property sets — these are reserved for buildingSMART standards. Use a company or project prefix (e.g., Acme_StructuralData).
4. ALWAYS check pset applicability before assigning a standard pset. Pset_WallCommon only applies to IfcWall/IfcWallType, not to IfcBeam.
5. NEVER pass None values in edit_qto expecting them to be kept. Quantities set to None are ALWAYS removed — there is no should_purge parameter for quantity sets.
6. ALWAYS use ifcopenshell.util.element.get_psets() for reading. NEVER traverse IsDefinedBy relationships manually.
7. ALWAYS use pset.add_pset() before pset.edit_pset(). The add function is idempotent — it returns the existing pset if one with the same name already exists.
8. NEVER assume bool maps to IfcInteger. Python bool is a subclass of int, but IfcOpenShell checks bool first and maps it to IfcBoolean.

Decision Tree: Property Operations