feat: upstream_block fields prototype (WIP)

cms/djangoapps/contentstore/helpers.py

@@ -11,9 +11,9 @@
 from django.conf import settings
 from django.utils.translation import gettext as _
 from opaque_keys.edx.keys import AssetKey, CourseKey, UsageKey
-from opaque_keys.edx.locator import DefinitionLocator, LocalId
+from opaque_keys.edx.locator import DefinitionLocator, LocalId, LibraryUsageLocatorV2
 from xblock.core import XBlock
-from xblock.fields import ScopeIds
+from xblock.fields import Scope, ScopeIds
 from xblock.runtime import IdGenerator
 from xmodule.contentstore.content import StaticContent
 from xmodule.contentstore.django import contentstore
@@ -23,6 +23,7 @@
 
 from cms.djangoapps.models.settings.course_grading import CourseGradingModel
 from openedx.core.djangoapps.site_configuration import helpers as configuration_helpers
+from openedx.core.djangoapps.content_libraries.api import get_library_block
 import openedx.core.djangoapps.content_staging.api as content_staging_api
 import openedx.core.djangoapps.content_tagging.api as content_tagging_api
 
@@ -293,7 +294,6 @@ def import_staged_content_from_user_clipboard(parent_key: UsageKey, request) ->
         staged_content_id=user_clipboard.content.id,
         static_files=static_files,
     )
-
     return new_xblock, notices
 
 
@@ -375,6 +375,20 @@ def _import_xml_node_to_parent(
     if copied_from_block:
         # Store a reference to where this block was copied from, in the 'copied_from_block' field (AuthoringMixin)
         temp_xblock.copied_from_block = copied_from_block
+        # If it was copied from a library, set the 'upstream_*' fields (AuthoringMixin)
+        copied_from_key = UsageKey.from_string(copied_from_block)  # @@TODO: param should be UsageKey, not str
+        if isinstance(copied_from_key, LibraryUsageLocatorV2):
+            temp_xblock.upstream_block = copied_from_block
+            temp_xblock.upstream_block_version = get_library_block(copied_from_key).version_num  # @@TODO: handle miss?
+            from openedx.core.djangoapps.xblock.api import load_block
+            from django.contrib.auth import get_user_model
+            upstream_xblock = load_block(copied_from_key, get_user_model().objects.get(id=user_id))
+            print(temp_xblock.upstream_block_settings)
+            temp_xblock.upstream_block_settings = {
+                field.name: getattr(upstream_xblock, field.name)
+                for field in upstream_xblock.fields
+                if field.scope == Scope.settings
+            }
     # Save the XBlock into modulestore. We need to save the block and its parent for this to work:
     new_xblock = store.update_item(temp_xblock, user_id, allow_not_found=True)
     parent_xblock.children.append(new_xblock.location)

cms/lib/xblock/authoring_mixin.py

@@ -8,7 +8,7 @@
 from django.conf import settings
 from web_fragments.fragment import Fragment
 from xblock.core import XBlock, XBlockMixin
-from xblock.fields import String, Scope
+from xblock.fields import Integer, String, Scope, Dict
 
 log = logging.getLogger(__name__)
 
@@ -51,3 +51,37 @@ def visibility_view(self, _context=None):
         scope=Scope.settings,
         enforce_type=True,
     )
+
+    # Note: upstream_* fields are only used by CMS. Not needed in the LMS.
+    upstream_block = String(
+        scope=Scope.settings,
+        help=(
+            "The usage key of a block (generally within a Content Library) which serves as a source of upstream "
+            "updates for this block, or None if there is no such upstream. Please note: It is valid for upstream_block "
+            "to hold a usage key for a block that does not exist (or does not *yet* exist) on this instance, "
+            "particularly if this block was imported from a different instance."
+        ),
+        hidden=True,
+        default=None,
+        enforce_type=True,
+    )
+    upstream_block_version = Integer(
+        scope=Scope.settings,
+        help=(
+            "The upstream_block's version number, at the time this block was created from it. "
+            "If this version is older than the upstream_block's latest version, then CMS will "
+            "allow this block to fetch updated content from upstream_block."
+        ),
+        hidden=True,
+        default=None,
+        enforce_type=True,
+    )
+    upstream_block_settings = Dict(
+        scope=Scope.settings,
+        help=(
+            "@@TODO"
+        ),
+        hidden=True,
+        default={},
+        enforce_type=True,
+    )

openedx/core/djangoapps/content_libraries/api.py

@@ -194,6 +194,7 @@ class LibraryXBlockMetadata:
     Class that represents the metadata about an XBlock in a content library.
     """
     usage_key = attr.ib(type=LibraryUsageLocatorV2)
+    version_num = attr.ib(type=int)
     display_name = attr.ib("")
     has_unpublished_changes = attr.ib(False)
     tags_count = attr.ib(0)
@@ -210,7 +211,8 @@ def from_component(cls, library_key, component):
                 component.local_key,
             ),
             display_name=component.versioning.draft.title,
-            has_unpublished_changes=component.versioning.has_unpublished_changes
+            has_unpublished_changes=component.versioning.has_unpublished_changes,
+            version_num=component.versioning.draft.version_num,
         )
 
 
@@ -651,6 +653,7 @@ def get_library_block(usage_key) -> LibraryXBlockMetadata:
         usage_key=usage_key,
         display_name=draft_version.title,
         has_unpublished_changes=(draft_version != published_version),
+        version_num=draft_version.version_num,
     )
 
 

xmodule/modulestore/inheritance.py

@@ -397,6 +397,11 @@ def default(self, block, name):
                     return field.read_json(ancestor)
                 else:
                     ancestor = ancestor.get_parent()
+        # @@TODO de-kludgify, move to core or mixin?
+        try:
+            return block.fields["upstream_block_settings"][name]
+        except KeyError:
+            pass
         return super().default(block, name)
 
 
@@ -448,4 +453,9 @@ def default(self, key):
         inheriting, this will raise KeyError which will cause the caller to use
         the field's global default.
         """
-        return self.inherited_settings[key.field_name]
+        try:
+            return self.inherited_settings[key.field_name]
+        except KeyError:
+            pass
+        # @@TODO de-kludgify, move to its own mixin, or core?
+        return self._fields.get("upstream_block_settings", {})[key.field_name]

xmodule/modulestore/split_mongo/split_mongo_kvs.py

@@ -163,7 +163,7 @@ def has_default_value(self, field_name):
         """
         Is the given field has default value in this kvs
         """
-        return field_name in self._defaults
+        return field_name in self._defaults or super().has_default_value(field_name)
 
     def default(self, key):
         """