First attempt at ripping out agnostic code into ifcopenshell.api namespace. See #1399.

src/ifcopenshell-python/ifcopenshell/api/structural/data.py

@@ -0,0 +1,66 @@
+class Data:
+    is_loaded = False
+    products = {}
+    boundary_conditions = {}
+    structural_analysis_models = {}
+
+    @classmethod
+    def purge(cls):
+        cls.is_loaded = False
+        cls.products = {}
+        cls.boundary_conditions = {}
+        cls.connected_structural_members = {}
+        cls.structural_analysis_models = {}
+
+    @classmethod
+    def load(cls, file, product_id=None):
+        cls._file = file
+        if product_id:
+            cls.boundary_conditions = {}
+            return cls.load_structural_connection(product_id)
+        cls.products = {}
+        cls.structural_analysis_models = {}
+        cls.load_structural_analysis_models()
+        cls.is_loaded = True
+
+    @classmethod
+    def load_structural_analysis_models(cls):
+        for model in cls._file.by_type("IfcStructuralAnalysisModel"):
+            if model.IsGroupedBy:
+                for rel in model.IsGroupedBy:
+                    for product in rel.RelatedObjects:
+                        cls.products.setdefault(product.id(), []).append(model.id())
+            data = model.get_info()
+            del data["OwnerHistory"]
+            del data["OrientationOf2DPlane"]
+
+            loaded_by = []
+            for load_group in model.LoadedBy or []:
+                loaded_by.append(load_group.id())
+            data["LoadedBy"] = loaded_by
+
+            has_results = []
+            for result_group in model.HasResults or []:
+                has_results.append(result_group.id())
+            data["HasResults"] = has_results
+
+            cls.structural_analysis_models[model.id()] = data
+
+    @classmethod
+    def load_structural_connection(cls, product_id):
+        connection = cls._file.by_id(product_id)
+        if connection.AppliedCondition:
+            data = connection.AppliedCondition.get_info()
+            for key, value in data.items():
+                if not value or key in ["Name", "type", "id"]:
+                    continue
+                data[key] = value.wrappedValue
+        else:
+            data = {}
+        cls.boundary_conditions[connection.id()] = data
+
+        cls.connected_structural_members[connection.id()] = [
+            rel.RelatingStructuralMember.id()
+            for rel in connection.ConnectsStructuralMembers or []
+        ]
+