refactor: adds _get_container method to api to reduce code duplication

Author: pomegranited

openedx/core/djangoapps/content_libraries/api/containers.py

@@ -19,14 +19,15 @@
     LIBRARY_CONTAINER_UPDATED,
 )
 from openedx_learning.api import authoring as authoring_api
-from openedx_learning.api import authoring_models
+from openedx_learning.api.authoring_models import Container
 
 from ..models import ContentLibrary
 from .libraries import PublishableItem
 
 
 # The public API is only the following symbols:
 __all__ = [
+    "ContentLibraryContainerNotFound",
     "ContainerMetadata",
     "ContainerType",
     "get_container",
@@ -37,6 +38,9 @@
 ]
 
 
+ContentLibraryContainerNotFound = Container.DoesNotExist
+
+
 class ContainerType(Enum):
     Unit = "unit"
 
@@ -50,7 +54,7 @@ class ContainerMetadata(PublishableItem):
     container_type: ContainerType
 
     @classmethod
-    def from_container(cls, library_key, container: authoring_models.Container, associated_collections=None):
+    def from_container(cls, library_key, container: Container, associated_collections=None):
         """
         Construct a ContainerMetadata object from a Container object.
         """
@@ -92,7 +96,7 @@ def from_container(cls, library_key, container: authoring_models.Container, asso
 
 def library_container_locator(
     library_key: LibraryLocatorV2,
-    container: authoring_models.Container,
+    container: Container,
 ) -> LibraryContainerLocator:
     """
     Returns a LibraryContainerLocator for the given library + container.
@@ -109,9 +113,11 @@ def library_container_locator(
     )
 
 
-def get_container(container_key: LibraryContainerLocator) -> ContainerMetadata:
+def _get_container(container_key: LibraryContainerLocator) -> Container:
     """
-    Get a container (a Section, Subsection, or Unit).
+    Internal method to fetch the Container object from its LibraryContainerLocator
+
+    Raises ContentLibraryContainerNotFound if no container found, or if the container has been soft deleted.
     """
     assert isinstance(container_key, LibraryContainerLocator)
     content_library = ContentLibrary.objects.get_by_key(container_key.library_key)
@@ -121,6 +127,16 @@ def get_container(container_key: LibraryContainerLocator) -> ContainerMetadata:
         learning_package.id,
         key=container_key.container_id,
     )
+    if container and container.versioning.draft:
+        return container
+    raise ContentLibraryContainerNotFound
+
+
+def get_container(container_key: LibraryContainerLocator) -> ContainerMetadata:
+    """
+    Get a container (a Section, Subsection, or Unit).
+    """
+    container = _get_container(container_key)
     container_meta = ContainerMetadata.from_container(container_key.library_key, container)
     assert container_meta.container_type.value == container_key.container_type
     return container_meta
@@ -181,15 +197,8 @@ def update_container(
     """
     Update a container (e.g. a Unit) title.
     """
-    assert isinstance(container_key, LibraryContainerLocator)
+    container = _get_container(container_key)
     library_key = container_key.library_key
-    content_library = ContentLibrary.objects.get_by_key(library_key)
-    learning_package = content_library.learning_package
-    assert learning_package is not None
-    container = authoring_api.get_container_by_key(
-        learning_package.id,
-        key=container_key.container_id,
-    )
 
     assert container.unit
     unit_version = authoring_api.create_next_unit_version(