# IfcOpenShell - IFC toolkit and geometry engine # Copyright (C) 2021 Dion Moult # # This file is part of IfcOpenShell. # # IfcOpenShell is free software: you can redistribute it and/or modify # it under the terms of the GNU Lesser General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # IfcOpenShell is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public License # along with IfcOpenShell. If not, see . import ifcopenshell import ifcopenshell.api.owner import ifcopenshell.guid import ifcopenshell.util.element import ifcopenshell.util.schema from typing import Optional, Union def add_reference( file: ifcopenshell.file, products: list[ifcopenshell.entity_instance], reference: Optional[ifcopenshell.entity_instance] = None, identification: Optional[str] = None, name: Optional[str] = None, classification: Optional[ifcopenshell.entity_instance] = None, is_lightweight=True, ) -> Union[ifcopenshell.entity_instance, None]: """Adds a new classification reference and assigns it to the list of products A classification reference is a single entry such as "Pr_12_23_34" that is part of an external classification system (such as Uniclass or Omniclass). References can be added to almost any object in IFC, including physical objects, object types, properties, tasks, costs, resources, or even resources such as profiles, documents, libraries, and so on. Classification references can be added in two ways. Option 1) specify a custom arbitrary reference, where you have to manually specify the identification (e.g. "Pr_12_23_45") and name (e.g. "Door Products"). Option 2) add a reference from an IFC classification library. The latter is preferred if you are using a common classification system such as Uniclass, as the library will be prepopulated with all the valid classifications already. Objects are allowed to have multiple classification references from multiple classification systems. This means that adding a new reference will not remove existing references. References can be inherited from types. This means that if an IfcWallType has a classification reference of Pr_12_23_34, then all IfcWall occurrences of that type automatically get the same classification of Pr_12_23_34. This means that it is more efficient to assign to types where possible. If a classification reference is assigned to both the type and an occurrence, then the assignment at the occurrence will override the type classification. :param product: The list of IFC objects, properties, or resources you want to associate the classification reference to. :type product: list[ifcopenshell.entity_instance] :param reference: The classification reference entity taken from an IFC classification library. If you supply this parameter, you will use option 2. :type reference: ifcopenshell.entity_instance, optional :param identification: If you choose option 1 and do not specify a reference, you may manually specify an identification code. The code is typically a short identifier and may have punctuation to separate the levels of hierarchy in the classificaion (e.g. Pr_12_23_34). :type identification: str, optional :param name: If you choose option 1 and do not specify a reference, you may manually specify a name. The name is typically human readable. :type name: str, optional :param classification: The IfcClassification entity in your IFC model (not the library, if you are doing option 2) that the reference is part of. :type classification: ifcopenshell.entity_instance :param is_lightweight: If you are doing option 2, choose whether or not to only add that particular reference (lighweight) or also add all of its parent references in the classification hierarchy (not lighweight). For example, adding a lightweight reference to Pr_12_23_34 will only add Pr_12_23_34, but adding a heavy reference to Pr_12_23_34 will also add Pr_12_23 and Pr_12. These parent references merely help describe the "tree" of classifications, but is generally unnecessary. Using lightweight classifications are recommended and is the default. :type is_lightweight: bool, optional :raises TypeError: If file is IFC2X3 and `products` has non-IfcRoot elements. :return: The newly added IfcClassificationReference or `None` if `products` was empty list. :rtype: Union[ifcopenshell.entity_instance, None] Example: .. code:: python # Option 1: adding and assigning a new reference from scratch wall_type = model.by_type("IfcWallType")[0] classification = ifcopenshell.api.classification.add_classification( model, classification="MyCustomClassification") ifcopenshell.api.classification.add_reference(model, products=[wall_type], classification=classification, identification="W_01", name="Interior Walls") # Option 2: adding a popular classification from a library library = ifcopenshell.open("/path/to/Uniclass.ifc") lib_classification = library.by_type("IfcClassification")[0] classification = ifcopenshell.api.classification.add_classification( model, classification=lib_classification) reference = [r for r in library.by_type("IfcClassificationReference") if r.Identification == "XYZ"][0] ifcopenshell.api.classification.add_reference(model, products=[wall_type], classification=classification, reference=reference) """ usecase = Usecase() usecase.file = file usecase.settings = { "products": products, "reference": reference, "identification": identification, "name": name, "classification": classification, "is_lightweight": is_lightweight, } return usecase.execute() class Usecase: def execute(self): if not self.settings["products"]: return if self.settings["reference"]: referenced = ifcopenshell.util.element.get_referenced_elements(self.settings["reference"]) if set(self.settings["products"]).issubset(referenced): # nothing to do, all elements already have this reference assigned return self.settings["reference"] self.rooted_products: set[ifcopenshell.entity_instance] = set() self.non_rooted_products: set[ifcopenshell.entity_instance] = set() for product in self.settings["products"]: if product.is_a("IfcRoot"): self.rooted_products.add(product) else: self.non_rooted_products.add(product) if self.non_rooted_products and self.file.schema == "IFC2X3": raise TypeError(f"Cannot add reference to non-IfcRoot element in IFC2X3: {self.non_rooted_products}.") if self.settings["reference"]: return self.add_from_library() return self.add_from_identification() def add_from_identification(self): reference = self.get_existing_reference(self.settings["identification"]) if not reference: reference = self.file.createIfcClassificationReference( Name=self.settings["name"], ReferencedSource=self.settings["classification"] ) if self.file.schema == "IFC2X3": reference.ItemReference = self.settings["identification"] else: reference.Identification = self.settings["identification"] self.update_relationships(reference) return reference def add_from_library(self) -> ifcopenshell.entity_instance: if hasattr(self.settings["reference"], "ItemReference"): identification = self.settings["reference"].ItemReference # IFC2X3 else: identification = self.settings["reference"].Identification reference = self.get_existing_reference(identification) if not reference: migrator = ifcopenshell.util.schema.Migrator() if self.settings["is_lightweight"]: old_referenced_source = self.settings["reference"].ReferencedSource self.settings["reference"].ReferencedSource = None else: classification_name = self.settings["classification"].Name existing_classification = [ c for c in self.file.by_type("IfcClassification") if c.Name == classification_name ] reference = migrator.migrate(self.settings["reference"], self.file) if self.settings["is_lightweight"]: reference.ReferencedSource = self.settings["classification"] self.settings["reference"].ReferencedSource = old_referenced_source elif existing_classification: to_delete = set() for traversed_reference in self.file.traverse(reference): if traversed_reference.ReferencedSource.is_a("IfcClassification"): to_delete.add(traversed_reference.ReferencedSource) traversed_reference.ReferencedSource = existing_classification[0] break for element in to_delete: self.file.remove(element) self.update_relationships(reference) return reference def get_existing_reference(self, identification: Optional[str] = None) -> Union[ifcopenshell.entity_instance, None]: for reference in self.file.by_type("IfcClassificationReference"): if self.file.schema == "IFC2X3": if reference.ItemReference == identification: return reference else: if reference.Identification == identification: return reference def update_relationships(self, reference: ifcopenshell.entity_instance) -> None: root_rel, non_root_rel = None, None if self.rooted_products: if self.file.schema == "IFC2X3": for rel in self.file.by_type("IfcRelAssociatesClassification"): if rel.RelatingClassification == reference: root_rel = rel break else: root_rel = next(iter(reference.ClassificationRefForObjects), None) if root_rel: related_objects = set(root_rel.RelatedObjects) | self.rooted_products root_rel.RelatedObjects = list(related_objects) ifcopenshell.api.owner.update_owner_history(self.file, **{"element": root_rel}) else: self.file.create_entity( "IfcRelAssociatesClassification", OwnerHistory=ifcopenshell.api.owner.create_owner_history(self.file), GlobalId=ifcopenshell.guid.new(), RelatedObjects=list(self.rooted_products), RelatingClassification=reference, ) if self.non_rooted_products: # NOTE: Only Ifc4+. Ifc2x3 is already handled by raising TypeError non_root_rel = next(iter(reference.ExternalReferenceForResources), None) if non_root_rel: related_objects = set(non_root_rel.RelatedResourceObjects) | self.non_rooted_products non_root_rel.RelatedResourceObjects = list(related_objects) else: self.file.create_entity( "IfcExternalReferenceRelationship", RelatingReference=reference, RelatedResourceObjects=list(self.non_rooted_products), )