143 lines
6.0 KiB
Python
143 lines
6.0 KiB
Python
# IfcOpenShell - IFC toolkit and geometry engine
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# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
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#
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# This file is part of IfcOpenShell.
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#
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# IfcOpenShell is free software: you can redistribute it and/or modify
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# it under the terms of the GNU Lesser General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# IfcOpenShell is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Lesser General Public License for more details.
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#
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# You should have received a copy of the GNU Lesser General Public License
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# along with IfcOpenShell. If not, see <http://www.gnu.org/licenses/>.
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from typing import Union
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import ifcopenshell
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import ifcopenshell.api.owner
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import ifcopenshell.guid
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import ifcopenshell.util.element
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def assign_declaration(
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file: ifcopenshell.file,
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definitions: list[ifcopenshell.entity_instance],
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relating_context: ifcopenshell.entity_instance,
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) -> Union[ifcopenshell.entity_instance, None]:
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"""Declares the list of elements to the project
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Feature was added in IFC4.
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All data in a model must be directly or indirectly related to the
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project. Most data is indirectly related, existing instead within the
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spatial decomposition tree. Other data, such as types, may be declared
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at the top level.
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Most of the time, the API handles declaration automatically for you.
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There is one scenario where you might want to explicitly declare objects
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to the project, and that's when you want to organise objects into
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project libraries for future use (such as an assets library). Assigning
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a declaration lets you say that an object belongs to a library.
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:param definitions: The list of objects you want to declare. Typically a list of assets.
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:param relating_context: The IfcProject, or more commonly the
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IfcProjectLibrary that you want the object to be part of.
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:return: The new IfcRelDeclares relationship or None if all definitions
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were already declared / do not support declaration.
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Example:
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.. code:: python
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# Programmatically generate a library. You could do this visually too.
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library = ifcopenshell.api.project.create_file()
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root = ifcopenshell.api.root.create_entity(library, ifc_class="IfcProject", name="Demo Library")
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context = ifcopenshell.api.root.create_entity(library,
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ifc_class="IfcProjectLibrary", name="Demo Library")
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# It's necessary to say our library is part of our project.
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ifcopenshell.api.project.assign_declaration(library, definitions=[context], relating_context=root)
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# Assign units for our example library
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unit = ifcopenshell.api.unit.add_si_unit(library,
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unit_type="LENGTHUNIT", prefix="MILLI")
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ifcopenshell.api.unit.assign_unit(library, units=[unit])
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# Let's create a single asset of a 200mm thick concrete wall
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wall_type = ifcopenshell.api.root.create_entity(library, ifc_class="IfcWallType", name="WAL01")
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concrete = ifcopenshell.api.material.add_material(file, name="CON", category="concrete")
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rel = ifcopenshell.api.material.assign_material(library,
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products=[wall_type], type="IfcMaterialLayerSet")
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layer = ifcopenshell.api.material.add_layer(library,
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layer_set=rel.RelatingMaterial, material=concrete)
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layer.Name = "Structure"
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layer.LayerThickness = 200
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# Mark our wall type as a reusable asset in our library.
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ifcopenshell.api.project.assign_declaration(library,
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definitions=[wall_type], relating_context=context)
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# All done, just for fun let's save our asset library to disk for later use.
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library.write("/path/to/my-library.ifc")
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"""
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all_declares = relating_context.Declares
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definitions_set = set(definitions)
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previous_declares_rels: set[ifcopenshell.entity_instance] = set()
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objects_without_contexts: list[ifcopenshell.entity_instance] = []
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objects_with_contexts: list[ifcopenshell.entity_instance] = []
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# check if there is anything to change
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for definition in definitions_set:
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has_context = getattr(definition, "HasContext", None)
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if has_context is None:
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continue
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object_rel = next(iter(has_context), None)
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if object_rel is None:
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objects_without_contexts.append(definition)
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continue
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# either rel doesn't exist or product is part of different rel
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if object_rel not in all_declares:
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previous_declares_rels.add(object_rel)
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objects_with_contexts.append(definition)
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objects_to_change = objects_without_contexts + objects_with_contexts
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# nothing to change
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if not objects_to_change:
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return None
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for has_context in previous_declares_rels:
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related_definitions = set(has_context.RelatedDefinitions) - set(objects_with_contexts)
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if related_definitions:
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has_context.RelatedDefinitions = list(related_definitions)
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ifcopenshell.api.owner.update_owner_history(file, element=has_context)
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else:
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history = has_context.OwnerHistory
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file.remove(has_context)
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if history:
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ifcopenshell.util.element.remove_deep2(file, history)
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declares = next(iter(all_declares), None)
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if declares:
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declares.RelatedDefinitions = list(set(declares.RelatedDefinitions) | set(objects_to_change))
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ifcopenshell.api.owner.update_owner_history(file, element=declares)
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else:
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declares = file.create_entity(
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"IfcRelDeclares",
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**{
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"GlobalId": ifcopenshell.guid.new(),
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"OwnerHistory": ifcopenshell.api.owner.create_owner_history(file),
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"RelatedDefinitions": list(objects_to_change),
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"RelatingContext": relating_context,
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},
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)
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return declares
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