Explicitly re-save XBlock fields during import

common/lib/xmodule/xmodule/modulestore/tests/test_xml_importer.py

@@ -0,0 +1,122 @@
+"""
+Tests for XML importer.
+"""
+from unittest import TestCase
+import mock
+from xblock.core import XBlock
+from xblock.fields import String, Scope, ScopeIds
+from xblock.runtime import Runtime, KvsFieldData, DictKeyValueStore
+from xmodule.x_module import XModuleMixin
+from xmodule.modulestore import Location
+from xmodule.modulestore.inheritance import InheritanceMixin
+from xmodule.modulestore.xml_importer import remap_namespace
+
+
+class StubXBlock(XBlock, XModuleMixin, InheritanceMixin):
+    """
+    Stub XBlock used for testing.
+    """
+    test_content_field = String(
+        help="A content field that will be explicitly set",
+        scope=Scope.content,
+        default="default value"
+    )
+
+    test_settings_field = String(
+        help="A settings field that will be explicitly set",
+        scope=Scope.settings,
+        default="default value"
+    )
+
+
+class RemapNamespaceTest(TestCase):
+    """
+    Test that remapping the namespace from import to the actual course location.
+    """
+
+    def setUp(self):
+        """
+        Create a stub XBlock backed by in-memory storage.
+        """
+        self.runtime = mock.MagicMock(Runtime)
+        self.field_data = KvsFieldData(kvs=DictKeyValueStore())
+        self.scope_ids = ScopeIds('Bob', 'stubxblock', '123', 'import')
+        self.xblock = StubXBlock(self.runtime, self.field_data, self.scope_ids)
+
+    def test_remap_namespace_native_xblock(self):
+
+        # Set the XBlock's location
+        self.xblock.location = Location("i4x://import/org/run/stubxblock")
+
+        # Explicitly set the content and settings fields
+        self.xblock.test_content_field = "Explicitly set"
+        self.xblock.test_settings_field = "Explicitly set"
+        self.xblock.save()
+
+        # Remap the namespace
+        target_location_namespace = Location("i4x://course/org/run/stubxblock")
+        remap_namespace(self.xblock, target_location_namespace)
+
+        # Check the XBlock's location
+        self.assertEqual(self.xblock.location, target_location_namespace)
+
+        # Check the values of the fields.
+        # The content and settings fields should be preserved
+        self.assertEqual(self.xblock.test_content_field, 'Explicitly set')
+        self.assertEqual(self.xblock.test_settings_field, 'Explicitly set')
+
+        # Expect that these fields are marked explicitly set
+        self.assertIn(
+            'test_content_field',
+            self.xblock.get_explicitly_set_fields_by_scope(scope=Scope.content)
+        )
+        self.assertIn(
+            'test_settings_field',
+            self.xblock.get_explicitly_set_fields_by_scope(scope=Scope.settings)
+        )
+
+    def test_remap_namespace_native_xblock_default_values(self):
+
+        # Set the XBlock's location
+        self.xblock.location = Location("i4x://import/org/run/stubxblock")
+
+        # Do NOT set any values, so the fields should use the defaults
+        self.xblock.save()
+
+        # Remap the namespace
+        target_location_namespace = Location("i4x://course/org/run/stubxblock")
+        remap_namespace(self.xblock, target_location_namespace)
+
+        # Check the values of the fields.
+        # The content and settings fields should be the default values
+        self.assertEqual(self.xblock.test_content_field, 'default value')
+        self.assertEqual(self.xblock.test_settings_field, 'default value')
+
+        # The fields should NOT appear in the explicitly set fields
+        self.assertNotIn(
+            'test_content_field',
+            self.xblock.get_explicitly_set_fields_by_scope(scope=Scope.content)
+        )
+        self.assertNotIn(
+            'test_settings_field',
+            self.xblock.get_explicitly_set_fields_by_scope(scope=Scope.settings)
+        )
+
+    def test_remap_namespace_native_xblock_inherited_values(self):
+
+        # Set the XBlock's location
+        self.xblock.location = Location("i4x://import/org/run/stubxblock")
+        self.xblock.save()
+
+        # Remap the namespace
+        target_location_namespace = Location("i4x://course/org/run/stubxblock")
+        remap_namespace(self.xblock, target_location_namespace)
+
+        # Inherited fields should NOT be explicitly set
+        self.assertNotIn(
+            'start', self.xblock.get_explicitly_set_fields_by_scope(scope=Scope.settings)
+        )
+        self.assertNotIn(
+            'graded', self.xblock.get_explicitly_set_fields_by_scope(scope=Scope.settings)
+        )
+

common/lib/xmodule/xmodule/modulestore/xml_importer.py

@@ -6,6 +6,7 @@ import json
 
 from .xml import XMLModuleStore, ImportSystem, ParentTracker
 from xmodule.modulestore import Location
+from xmodule.x_module import XModuleDescriptor
 from xblock.fields import Scope, Reference, ReferenceList, ReferenceValueDict
 from xmodule.contentstore.content import StaticContent
 from .inheritance import own_metadata
@@ -488,11 +489,34 @@ def remap_namespace(module, target_location_namespace):
     # This looks a bit wonky as we need to also change the 'name' of the
     # imported course to be what the caller passed in
     if module.location.category != 'course':
+
+        # Retrieve the content and settings fields that have been explicitly set
+        # to ensure that they are properly re-keyed in the XBlock field data.
+        if isinstance(module, XModuleDescriptor):
+            rekey_fields = []
+        else:
+            rekey_fields = (
+                module.get_explicitly_set_fields_by_scope(Scope.content).keys() +
+                module.get_explicitly_set_fields_by_scope(Scope.settings).keys()
+            )
+
         module.location = module.location.replace(
             tag=target_location_namespace.tag,
             org=target_location_namespace.org,
             course=target_location_namespace.course
         )
+
+        # Native XBlocks store the field data in a key-value store
+        # in which one component of the key is the XBlock's location (equivalent to "scope_ids").
+        # Since we've changed the XBlock's location, we need to re-save
+        # all the XBlock's fields so they will be stored using the new location in the key.
+        # However, since XBlocks only save "dirty" fields, we need to first
+        # explicitly set each field to its current value before triggering the save.
+        if len(rekey_fields) > 0:
+            for rekey_field_name in rekey_fields:
+                setattr(module, rekey_field_name, getattr(module, rekey_field_name))
+            module.save()
+
     else:
         #
         # module is a course module