refactor: Duplicate and update primitives made available.

cms/djangoapps/contentstore/tests/test_libraries.py

@@ -16,7 +16,7 @@
 
 from cms.djangoapps.contentstore.tests.utils import AjaxEnabledTestClient, parse_json
 from cms.djangoapps.contentstore.utils import reverse_library_url, reverse_url, reverse_usage_url
-from cms.djangoapps.contentstore.views.item import _duplicate_item
+from cms.djangoapps.contentstore.views.item import duplicate_block
 from cms.djangoapps.contentstore.views.preview import _load_preview_module
 from cms.djangoapps.contentstore.views.tests.test_library import LIBRARY_REST_URL
 from cms.djangoapps.course_creators.views import add_user_with_status_granted
@@ -947,7 +947,7 @@ def test_persistent_overrides(self, duplicate):
         if duplicate:
             # Check that this also works when the RCB is duplicated.
             self.lc_block = modulestore().get_item(
-                _duplicate_item(self.course.location, self.lc_block.location, self.user)
+                duplicate_block(self.course.location, self.lc_block.location, self.user)
             )
             self.problem_in_course = modulestore().get_item(self.lc_block.children[0])
         else:
@@ -1006,7 +1006,7 @@ def test_duplicated_version(self):
 
         # Duplicate self.lc_block:
         duplicate = store.get_item(
-            _duplicate_item(self.course.location, self.lc_block.location, self.user)
+            duplicate_block(self.course.location, self.lc_block.location, self.user)
         )
         # The duplicate should have identical children to the original:
         self.assertEqual(len(duplicate.children), 1)

cms/djangoapps/contentstore/views/item.py

@@ -239,11 +239,11 @@ def xblock_handler(request, usage_key_string=None):
                     status=400
                 )
 
-            dest_usage_key = _duplicate_item(
+            dest_usage_key = duplicate_block(
                 parent_usage_key,
                 duplicate_source_usage_key,
                 request.user,
-                request.json.get('display_name'),
+                display_name=request.json.get('display_name'),
             )
             return JsonResponse({
                 'locator': str(dest_usage_key),
@@ -873,47 +873,88 @@ def _move_item(source_usage_key, target_parent_usage_key, user, target_index=Non
         return JsonResponse(context)
 
 
-def _duplicate_item(parent_usage_key, duplicate_source_usage_key, user, display_name=None, is_child=False):
+def gather_block_attributes(source_item, display_name=None, is_child=False):
+    """
+    Gather all the attributes of the source block that need to be copied over to a new or updated block.
+    """
+    # Update the display name to indicate this is a duplicate (unless display name provided).
+    # Can't use own_metadata(), b/c it converts data for JSON serialization -
+    # not suitable for setting metadata of the new block
+    duplicate_metadata = {}
+    for field in source_item.fields.values():
+        if field.scope == Scope.settings and field.is_set_on(source_item):
+            duplicate_metadata[field.name] = field.read_from(source_item)
+
+    if is_child:
+        display_name = display_name or source_item.display_name or source_item.category
+
+    if display_name is not None:
+        duplicate_metadata['display_name'] = display_name
+    else:
+        if source_item.display_name is None:
+            duplicate_metadata['display_name'] = _("Duplicate of {0}").format(source_item.category)
+        else:
+            duplicate_metadata['display_name'] = _("Duplicate of '{0}'").format(source_item.display_name)
+
+    asides_to_create = []
+    for aside in source_item.runtime.get_asides(source_item):
+        for field in aside.fields.values():
+            if field.scope in (Scope.settings, Scope.content,) and field.is_set_on(aside):
+                asides_to_create.append(aside)
+                break
+
+    for aside in asides_to_create:
+        for field in aside.fields.values():
+            if field.scope not in (Scope.settings, Scope.content,):
+                field.delete_from(aside)
+    return duplicate_metadata, asides_to_create
+
+
+def update_from_source(*, source_block, destination_block, user_id):
+    """
+    Update a block to have all the settings and attributes of another source.
+
+    Copies over all attributes and settings of a source block to a destination
+    block. Blocks must be the same type. This function does not modify or duplicate
+    children.
+    """
+    duplicate_metadata, asides = gather_block_attributes(source_block, display_name=source_block.display_name)
+    for key, value in duplicate_metadata.items():
+        setattr(destination_block, key, value)
+    for key, value in source_block.get_explicitly_set_fields_by_scope(Scope.content).items():
+        setattr(destination_block, key, value)
+    modulestore().update_item(
+        destination_block,
+        user_id,
+        metadata=duplicate_metadata,
+        asides=asides,
+    )
+
+
+def duplicate_block(
+    parent_usage_key,
+    duplicate_source_usage_key,
+    user,
+    dest_usage_key=None,
+    display_name=None,
+    shallow=False,
+    is_child=False
+):
     """
     Duplicate an existing xblock as a child of the supplied parent_usage_key.
     """
     store = modulestore()
     with store.bulk_operations(duplicate_source_usage_key.course_key):
         source_item = store.get_item(duplicate_source_usage_key)
-        # Change the blockID to be unique.
-        dest_usage_key = source_item.location.replace(name=uuid4().hex)
-        category = dest_usage_key.block_type
-
-        # Update the display name to indicate this is a duplicate (unless display name provided).
-        # Can't use own_metadata(), b/c it converts data for JSON serialization -
-        # not suitable for setting metadata of the new block
-        duplicate_metadata = {}
-        for field in source_item.fields.values():
-            if field.scope == Scope.settings and field.is_set_on(source_item):
-                duplicate_metadata[field.name] = field.read_from(source_item)
-
-        if is_child:
-            display_name = display_name or source_item.display_name or source_item.category
-
-        if display_name is not None:
-            duplicate_metadata['display_name'] = display_name
-        else:
-            if source_item.display_name is None:
-                duplicate_metadata['display_name'] = _("Duplicate of {0}").format(source_item.category)
-            else:
-                duplicate_metadata['display_name'] = _("Duplicate of '{0}'").format(source_item.display_name)
+        if not dest_usage_key:
+            # Change the blockID to be unique.
+            dest_usage_key = source_item.location.replace(name=uuid4().hex)
 
-        asides_to_create = []
-        for aside in source_item.runtime.get_asides(source_item):
-            for field in aside.fields.values():
-                if field.scope in (Scope.settings, Scope.content,) and field.is_set_on(aside):
-                    asides_to_create.append(aside)
-                    break
+        category = dest_usage_key.block_type
 
-        for aside in asides_to_create:
-            for field in aside.fields.values():
-                if field.scope not in (Scope.settings, Scope.content,):
-                    field.delete_from(aside)
+        duplicate_metadata, asides_to_create = gather_block_attributes(
+            source_item, display_name=display_name, is_child=is_child,
+        )
 
         dest_module = store.create_item(
             user.id,
@@ -937,11 +978,11 @@ def _duplicate_item(parent_usage_key, duplicate_source_usage_key, user, display_
 
         # Children are not automatically copied over (and not all xblocks have a 'children' attribute).
         # Because DAGs are not fully supported, we need to actually duplicate each child as well.
-        if source_item.has_children and not children_handled:
+        if source_item.has_children and not shallow and not children_handled:
             dest_module.children = dest_module.children or []
             for child in source_item.children:
-                dupe = _duplicate_item(dest_module.location, child, user=user, is_child=True)
-                if dupe not in dest_module.children:  # _duplicate_item may add the child for us.
+                dupe = duplicate_block(dest_module.location, child, user=user, is_child=True)
+                if dupe not in dest_module.children:  # _duplicate_block may add the child for us.
                     dest_module.children.append(dupe)
             store.update_item(dest_module, user.id)
 

cms/djangoapps/contentstore/views/tests/test_item.py

@@ -68,7 +68,7 @@
     _get_source_index,
     _xblock_type_and_display_name,
     add_container_page_publishing_info,
-    create_xblock_info,
+    create_xblock_info, duplicate_block, update_from_source,
 )
 
 
@@ -780,6 +780,29 @@ def verify_name(source_usage_key, parent_usage_key, expected_name, display_name=
         # Now send a custom display name for the duplicate.
         verify_name(self.seq_usage_key, self.chapter_usage_key, "customized name", display_name="customized name")
 
+    def test_shallow_duplicate(self):
+        """
+        Test that shallow_duplicate creates a new block.
+        """
+        source_course = CourseFactory()
+        user = UserFactory.create()
+        source_chapter = ItemFactory(parent=source_course, category='chapter', display_name='Source Chapter')
+        ItemFactory(parent=source_chapter, category='html', display_name='Child')
+        # Refresh.
+        source_chapter = self.store.get_item(source_chapter.location)
+        self.assertEqual(len(source_chapter.get_children()), 1)
+        destination_course = CourseFactory()
+        destination_location = duplicate_block(
+            parent_usage_key=destination_course.location, duplicate_source_usage_key=source_chapter.location,
+            user=user,
+            display_name=source_chapter.display_name,
+            shallow=True,
+        )
+        # Refresh here, too, just to be sure.
+        destination_chapter = self.store.get_item(destination_location)
+        self.assertEqual(len(destination_chapter.get_children()), 0)
+        self.assertEqual(destination_chapter.display_name, 'Source Chapter')
+
 
 @ddt.ddt
 class TestMoveItem(ItemTest):
@@ -3587,3 +3610,111 @@ def test_creator_show_delete_button_with_waffle(self):
             )
 
         self.assertFalse(xblock_info['show_delete_button'])
+
+
+@patch('xmodule.modulestore.split_mongo.caching_descriptor_system.CachingDescriptorSystem.applicable_aside_types',
+       lambda self, block: ['test_aside'])
+class TestUpdateFromSource(ModuleStoreTestCase):
+    """
+    Test update_from_source.
+    """
+
+    def setUp(self):
+        """
+        Set up the runtime for tests.
+        """
+        super().setUp()
+        key_store = DictKeyValueStore()
+        field_data = KvsFieldData(key_store)
+        self.runtime = TestRuntime(services={'field-data': field_data})
+
+    def create_source_block(self, course):
+        """
+        Create a chapter with all the fixings.
+        """
+        source_block = ItemFactory(
+            parent=course,
+            category='course_info',
+            display_name='Source Block',
+            metadata={'due': datetime(2010, 11, 22, 4, 0, tzinfo=UTC)},
+        )
+
+        def_id = self.runtime.id_generator.create_definition('html')
+        usage_id = self.runtime.id_generator.create_usage(def_id)
+
+        aside = AsideTest(scope_ids=ScopeIds('user', 'html', def_id, usage_id), runtime=self.runtime)
+        aside.field11 = 'html_new_value1'
+
+        # The data attribute is handled in a special manner and should be updated.
+        source_block.data = '<div>test</div>'
+        # This field is set on the content scope (definition_data), which should be updated.
+        source_block.items = ['test', 'beep']
+
+        self.store.update_item(source_block, self.user.id, asides=[aside])
+
+        # quick sanity checks
+        source_block = self.store.get_item(source_block.location)
+        self.assertEqual(source_block.due, datetime(2010, 11, 22, 4, 0, tzinfo=UTC))
+        self.assertEqual(source_block.display_name, 'Source Block')
+        self.assertEqual(source_block.runtime.get_asides(source_block)[0].field11, 'html_new_value1')
+        self.assertEqual(source_block.data, '<div>test</div>')
+        self.assertEqual(source_block.items, ['test', 'beep'])
+
+        return source_block
+
+    def check_updated(self, source_block, destination_key):
+        """
+        Check that the destination block has been updated to match our source block.
+        """
+        revised = self.store.get_item(destination_key)
+        self.assertEqual(source_block.display_name, revised.display_name)
+        self.assertEqual(source_block.due, revised.due)
+        self.assertEqual(revised.data, source_block.data)
+        self.assertEqual(revised.items, source_block.items)
+
+        self.assertEqual(
+            revised.runtime.get_asides(revised)[0].field11,
+            source_block.runtime.get_asides(source_block)[0].field11,
+        )
+
+    @XBlockAside.register_temp_plugin(AsideTest, 'test_aside')
+    def test_update_from_source(self):
+        """
+        Test that update_from_source updates the destination block.
+        """
+        course = CourseFactory()
+        user = UserFactory.create()
+
+        source_block = self.create_source_block(course)
+
+        destination_block = ItemFactory(parent=course, category='course_info', display_name='Destination Problem')
+        update_from_source(source_block=source_block, destination_block=destination_block, user_id=user.id)
+        self.check_updated(source_block, destination_block.location)
+
+    @XBlockAside.register_temp_plugin(AsideTest, 'test_aside')
+    def test_update_clobbers(self):
+        """
+        Verify that our update clobbers everything.
+        """
+        course = CourseFactory()
+        user = UserFactory.create()
+
+        source_block = self.create_source_block(course)
+
+        destination_block = ItemFactory(
+            parent=course,
+            category='course_info',
+            display_name='Destination Chapter',
+            metadata={'due': datetime(2025, 10, 21, 6, 5, tzinfo=UTC)},
+        )
+
+        def_id = self.runtime.id_generator.create_definition('html')
+        usage_id = self.runtime.id_generator.create_usage(def_id)
+        aside = AsideTest(scope_ids=ScopeIds('user', 'html', def_id, usage_id), runtime=self.runtime)
+        aside.field11 = 'Other stuff'
+        destination_block.data = '<div>other stuff</div>'
+        destination_block.items = ['other stuff', 'boop']
+        self.store.update_item(destination_block, user.id, asides=[aside])
+
+        update_from_source(source_block=source_block, destination_block=destination_block, user_id=user.id)
+        self.check_updated(source_block, destination_block.location)

common/lib/xmodule/xmodule/modulestore/split_mongo/split.py

@@ -57,7 +57,6 @@
 
 import copy
 import datetime
-import hashlib
 import logging
 from collections import defaultdict
 from importlib import import_module
@@ -102,7 +101,7 @@
 )
 from xmodule.modulestore.split_mongo import BlockKey, CourseEnvelope
 from xmodule.modulestore.split_mongo.mongo_connection import DuplicateKeyError, DjangoFlexPersistenceBackend
-from xmodule.modulestore.store_utilities import DETACHED_XBLOCK_TYPES
+from xmodule.modulestore.store_utilities import DETACHED_XBLOCK_TYPES, derived_key
 from xmodule.partitions.partitions_service import PartitionService
 
 from ..exceptions import ItemNotFoundError
@@ -2428,23 +2427,14 @@ def _copy_from_template(
 
         for usage_key in source_keys:
             src_course_key = usage_key.course_key
-            hashable_source_id = src_course_key.for_version(None)
             block_key = BlockKey(usage_key.block_type, usage_key.block_id)
             source_structure = source_structures[src_course_key]
 
             if block_key not in source_structure['blocks']:
                 raise ItemNotFoundError(usage_key)
             source_block_info = source_structure['blocks'][block_key]
 
-            # Compute a new block ID. This new block ID must be consistent when this
-            # method is called with the same (source_key, dest_structure) pair
-            unique_data = "{}:{}:{}".format(
-                str(hashable_source_id).encode("utf-8"),
-                block_key.id,
-                new_parent_block_key.id,
-            )
-            new_block_id = hashlib.sha1(unique_data.encode('utf-8')).hexdigest()[:20]
-            new_block_key = BlockKey(block_key.type, new_block_id)
+            new_block_key = derived_key(src_course_key, block_key, new_parent_block_key)
 
             # Now clone block_key to new_block_key:
             new_block_info = copy.deepcopy(source_block_info)