api for assigning/unassigning flow controls #3981

src/ifcopenshell-python/ifcopenshell/api/system/assign_flow_control.py

@@ -0,0 +1,85 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# 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 <http://www.gnu.org/licenses/>.
+
+import ifcopenshell
+import ifcopenshell.api
+
+
+class Usecase:
+    def __init__(self, file, relating_flow_element=None, related_flow_control=None):
+        """Assigns to the flow element control element that either sense or control
+        some aspect of the flow element.
+
+        Note that control can be assigned only to the one flow element.
+
+        :param related_flow_control: IfcDistributionControlElement
+            which may be used to impart control on the flow element
+        :type related_flow_control: ifcopenshell.entity_instance.entity_instance
+        :param relating_flow_element: The IfcDistributionFlowElement that is being controlled / sensed
+        :type relating_flow_element: ifcopenshell.entity_instance.entity_instance
+        :return: Matching or newly created IfcRelFlowControlElements. If control
+            is already assigned to some other element method will return None.
+        :rtype: ifcopenshell.entity_instance.entity_instance, None
+
+        Example:
+
+        .. code:: python
+
+            flow_element = model.createIfcFlowSegment()
+            flow_control = model.createIfcController()
+            relation = ifcopenshell.api.run(
+                "system.assign_flow_control", model,
+                related_flow_control=flow_control, relating_flow_element=flow_element
+            )
+        """
+        self.file = file
+        self.settings = {
+            "relating_flow_element": relating_flow_element,
+            "related_flow_control": related_flow_control,
+        }
+
+    def execute(self):
+        if self.settings["related_flow_control"].AssignedToFlowElement:
+            # only 1 control per 1 flow element is possible
+            assignment = self.settings["related_flow_control"].AssignedToFlowElement[0]
+            if assignment.RelatingFlowElement == self.settings["relating_flow_element"]:
+                return assignment
+            # return None if this control is already assigned to another flow element
+            return
+
+        if self.settings["relating_flow_element"].HasControlElements:
+            assignment = self.settings["relating_flow_element"].HasControlElements[0]
+            if self.settings["related_flow_control"] in assignment.RelatedControlElements:
+                return assignment
+
+            related_flow_controls = set(assignment.RelatedControlElements)
+            related_flow_controls.add(self.settings["related_flow_control"])
+            assignment.RelatedControlElements = list(related_flow_controls)
+            ifcopenshell.api.run("owner.update_owner_history", self.file, **{"element": assignment})
+            return assignment
+
+        assignment = self.file.create_entity(
+            "IfcRelFlowControlElements",
+            **{
+                "GlobalId": ifcopenshell.guid.new(),
+                "OwnerHistory": ifcopenshell.api.run("owner.create_owner_history", self.file),
+                "RelatedControlElements": [self.settings["related_flow_control"]],
+                "RelatingFlowElement": self.settings["relating_flow_element"],
+            },
+        )
+        return assignment

src/ifcopenshell-python/ifcopenshell/api/system/unassign_flow_control.py

@@ -0,0 +1,72 @@
+# IfcOpenShell - IFC toolkit and geometry engine
+# Copyright (C) 2021 Dion Moult <dion@thinkmoult.com>
+#
+# 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 <http://www.gnu.org/licenses/>.
+
+import ifcopenshell
+import ifcopenshell.api
+
+
+class Usecase:
+    def __init__(self, file, relating_flow_element=None, related_flow_control=None):
+        """Unassigns flow control element from the flow element.
+
+        :param related_flow_control: IfcDistributionControlElement controling the
+            flow element
+        :type related_flow_control: ifcopenshell.entity_instance.entity_instance
+        :param relating_flow_element: The IfcDistributionFlowElement that is being controlled
+        :type relating_flow_element: ifcopenshell.entity_instance.entity_instance
+        :return: If the control still is related to other objects, the
+            IfcRelFlowControlElements is returned, otherwise None.
+        :rtype: ifcopenshell.entity_instance.entity_instance, None
+
+        Example:
+
+        .. code:: python
+
+            # assign control to the flow element
+            flow_element = self.file.createIfcFlowSegment()
+            flow_control = self.file.createIfcController()
+            relation = ifcopenshell.api.run(
+                "system.assign_flow_control", self.file,
+                relating_control=flow_control, related_object=flow_element
+            )
+
+            # und unassign it
+            ifcopenshell.api.run("system.unassign_flow_control", self.file,
+                relating_control=flow_control, related_object=flow_element
+            )
+        """
+
+        self.file = file
+        self.settings = {
+            "relating_flow_element": relating_flow_element,
+            "related_flow_control": related_flow_control,
+        }
+
+    def execute(self):
+        if not self.settings["related_flow_control"].AssignedToFlowElement:
+            return
+        assignment = self.settings["related_flow_control"].AssignedToFlowElement[0]
+        if assignment.RelatingFlowElement != self.settings["relating_flow_element"]:
+            return
+        if len(assignment.RelatedControlElements) == 1:
+            return self.file.remove(assignment)
+        related_flow_controls = list(assignment.RelatedControlElements)
+        related_flow_controls.remove(self.settings["related_flow_control"])
+        assignment.RelatedControlElements = related_flow_controls
+        ifcopenshell.api.run("owner.update_owner_history", self.file, **{"element": assignment})
+        return assignment