refactor: hold element in StaticStructureElementInstaance

Author: yt-ms

src/structurizr/model/container_instance.py

@@ -20,6 +20,7 @@
 
 from pydantic import Field
 
+from .container import Container
 from .static_structure_element_instance import (
     StaticStructureElementInstance,
     StaticStructureElementInstanceIO,
@@ -28,7 +29,6 @@
 
 
 if TYPE_CHECKING:
-    from .container import Container
     from .deployment_node import DeploymentNode
     from .model import Model
 
@@ -45,12 +45,16 @@ class ContainerInstanceIO(StaticStructureElementInstanceIO):
 class ContainerInstance(StaticStructureElementInstance):
     """Represents a container instance which can be added to a deployment node."""
 
-    def __init__(self, *, container: "Container", **kwargs) -> None:
+    def __init__(self, *, container: Container, **kwargs) -> None:
         """Initialize a container instance."""
         super().__init__(element=container, **kwargs)
-        self.container = container
         self.tags.add(Tags.CONTAINER_INSTANCE)
 
+    @property
+    def container(self) -> Container:
+        """Return the container for this instance."""
+        return self.element
+
     @property
     def container_id(self) -> str:
         """Return the ID of the container for this instance."""

src/structurizr/model/software_system_instance.py

@@ -48,9 +48,13 @@ class SoftwareSystemInstance(StaticStructureElementInstance):
     def __init__(self, *, software_system: SoftwareSystem, **kwargs) -> None:
         """Initialize a software system instance."""
         super().__init__(element=software_system, **kwargs)
-        self.software_system = software_system
         self.tags.add(Tags.SOFTWARE_SYSTEM_INSTANCE)
 
+    @property
+    def software_system(self) -> SoftwareSystem:
+        """Return the software system for this instance."""
+        return self.element
+
     @property
     def software_system_id(self) -> str:
         """Return the ID of the software system for this instance."""

src/structurizr/model/static_structure_element_instance.py

@@ -55,6 +55,7 @@ def __init__(
         # StaticStructureElementInstance.getName() in the Java API.
         kwargs["name"] = element.name
         super().__init__(**kwargs)
+        self.element = element
         self.instance_id = instance_id
         self.health_checks = set(health_checks)
         self.parent = parent