feat: Python api and rest api for History log logic [FC-0123]

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

@@ -3,6 +3,7 @@
 """
 from __future__ import annotations
 from dataclasses import dataclass
+from datetime import datetime
 
 from django.utils.translation import gettext as _
 from opaque_keys.edx.locator import LibraryUsageLocatorV2
@@ -15,6 +16,7 @@
 __all__ = [
     "LibraryXBlockMetadata",
     "LibraryXBlockStaticFile",
+    "LibraryComponentDraftHistoryEntry",
 ]
 
 
@@ -64,6 +66,17 @@ def from_component(cls, library_key, component, associated_collections=None):
         )
 
 
+@dataclass(frozen=True)
+class LibraryComponentDraftHistoryEntry:
+    """
+    One entry in the draft change history of a library component.
+    """
+    changed_by: object       # AUTH_USER_MODEL instance or None
+    changed_at: datetime
+    title: str               # title at time of change
+    action: str              # "edited" | "renamed"
+
+
 @dataclass(frozen=True)
 class LibraryXBlockStaticFile:
     """

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

@@ -58,7 +58,7 @@
     InvalidNameError,
     LibraryBlockAlreadyExists,
 )
-from .block_metadata import LibraryXBlockMetadata, LibraryXBlockStaticFile
+from .block_metadata import LibraryComponentDraftHistoryEntry, LibraryXBlockMetadata, LibraryXBlockStaticFile
 from .containers import (
     create_container,
     get_container,
@@ -98,6 +98,7 @@
     "add_library_block_static_asset_file",
     "delete_library_block_static_asset_file",
     "publish_component_changes",
+    "get_library_component_draft_history",
 ]
 
 
@@ -191,6 +192,37 @@ def get_library_block(usage_key: LibraryUsageLocatorV2, include_collections=Fals
     return xblock_metadata
 
 
+def get_library_component_draft_history(usage_key: LibraryUsageLocatorV2) -> list[LibraryComponentDraftHistoryEntry]:
+    """
+    Return the draft change history for a library component since its last publication,
+    ordered from most recent to oldest.
+
+    Raises ContentLibraryBlockNotFound if the component does not exist.
+    """
+    try:
+        component = get_component_from_usage_key(usage_key)
+    except ObjectDoesNotExist as exc:
+        raise ContentLibraryBlockNotFound(usage_key) from exc
+
+    records = content_api.get_entity_draft_history(component.publishable_entity)
+
+    return [
+        LibraryComponentDraftHistoryEntry(
+            changed_by=record.draft_change_log.changed_by,
+            changed_at=record.draft_change_log.changed_at,
+            title=(record.new_version or record.old_version).title,
+            action=_resolve_draft_action(record.old_version, record.new_version),
+        )
+        for record in records
+    ]
+
+
+def _resolve_draft_action(old_version, new_version) -> str:
+    if old_version and new_version and old_version.title != new_version.title:
+        return "renamed"
+    return "edited"
+
+
 def set_library_block_olx(usage_key: LibraryUsageLocatorV2, new_olx_str: str) -> ComponentVersion:
     """
     Replace the OLX source of the given XBlock.
@@ -682,7 +714,6 @@ def import_staged_content_from_user_clipboard(library_key: LibraryLocatorV2, use
             now,
         )
 
-
 def get_or_create_olx_media_type(block_type: str) -> MediaType:
     """
     Get or create a MediaType for the block type.

openedx/core/djangoapps/content_libraries/rest_api/blocks.py

@@ -140,6 +140,25 @@ def delete(self, request, usage_key_str):  # pylint: disable=unused-argument
         return Response({})
 
 
+@method_decorator(non_atomic_requests, name="dispatch")
+@view_auth_classes()
+class LibraryComponentDraftHistoryView(APIView):
+    """
+    View to get the draft change history of a library component.
+    """
+    serializer_class = serializers.LibraryComponentDraftHistoryEntrySerializer
+
+    @convert_exceptions
+    def get(self, request, usage_key_str):
+        """
+        Get the draft change history for a library component since its last publication.
+        """
+        key = LibraryUsageLocatorV2.from_string(usage_key_str)
+        api.require_permission_for_library_key(key.lib_key, request.user, permissions.CAN_VIEW_THIS_CONTENT_LIBRARY)
+        history = api.get_library_component_draft_history(key)
+        return Response(self.serializer_class(history, many=True).data)
+
+
 @method_decorator(non_atomic_requests, name="dispatch")
 @view_auth_classes()
 class LibraryBlockAssetListView(APIView):

openedx/core/djangoapps/content_libraries/rest_api/serializers.py

@@ -180,6 +180,21 @@ class LibraryXBlockMetadataSerializer(PublishableItemSerializer):
     block_type = serializers.CharField(source="usage_key.block_type")
 
 
+class LibraryComponentDraftHistoryEntrySerializer(serializers.Serializer):
+    """
+    Serializer for a single entry in the draft history of a library component.
+    """
+    changed_by = serializers.SerializerMethodField()
+    changed_at = serializers.DateTimeField(format=DATETIME_FORMAT, read_only=True)
+    title = serializers.CharField()
+    action = serializers.CharField()
+
+    def get_changed_by(self, obj) -> str | None:
+        if obj.changed_by is None:
+            return None
+        return obj.changed_by.username
+
+
 class LibraryXBlockTypeSerializer(serializers.Serializer):
     """
     Serializer for LibraryXBlockType

openedx/core/djangoapps/content_libraries/urls.py

@@ -77,6 +77,8 @@
             path('assets/', blocks.LibraryBlockAssetListView.as_view()),
             path('assets/<path:file_path>', blocks.LibraryBlockAssetView.as_view()),
             path('publish/', blocks.LibraryBlockPublishView.as_view()),
+            # Get the draft change history for this block
+            path('draft_history/', blocks.LibraryComponentDraftHistoryView.as_view()),
             # Future: discard changes for just this one block
         ])),
         # Containers are Sections, Subsections, and Units