refactor: we don't need _unwrapped_field_data any more

lms/djangoapps/courseware/tests/test_block_render.py

@@ -487,11 +487,10 @@ class BlockRenderTestCase(SharedModuleStoreTestCase, LoginEnrollmentTestCase):
             self.mock_user, request, block, field_data_cache, course.id, course=course
         )
 
-        # check that _unwrapped_field_data is the same as the original
+        # check that block.runtime.service(block, 'field-data-unbound') is the same as the original
         # _field_data, but now _field_data as been reset.
-        # pylint: disable=protected-access
-        assert block._unwrapped_field_data is original_field_data  # lint-amnesty, pylint: disable=no-member
-        assert block._unwrapped_field_data is not block._field_data  # lint-amnesty, pylint: disable=no-member
+        assert block.runtime.service(block, 'field-data-unbound') is original_field_data
+        assert block.runtime.service(block, 'field-data-unbound') is not block._field_data  # pylint: disable=protected-access, line-too-long
 
         # now bind this block to a few other students
         for user in [UserFactory(), UserFactory(), self.mock_user]:
@@ -513,7 +512,8 @@ class BlockRenderTestCase(SharedModuleStoreTestCase, LoginEnrollmentTestCase):
 
         # the OverrideFieldData should point to the date FieldData
         assert isinstance(block._field_data._authored_data._source.fallback, DateLookupFieldData)    # lint-amnesty, pylint: disable=no-member, line-too-long
-        assert block._field_data._authored_data._source.fallback._defaults is block._unwrapped_field_data    # lint-amnesty, pylint: disable=no-member, line-too-long
+        assert block._field_data._authored_data._source.fallback._defaults \
+            is block.runtime.service(block, 'field-data-unbound')
 
     def test_hash_resource(self):
         """

xmodule/modulestore/mongo/base.py

@@ -170,6 +170,12 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
     A system that has a cache of block json that it will use to load blocks
     from, with a backup of calling to the underlying modulestore for more data
     """
+
+    # This CachingDescriptorSystem runtime sets block._field_data on each block via construct_xblock_from_class(),
+    # rather than the newer approach of providing a "field-data" service via runtime.service(). As a result, during
+    # bind_for_student() we can't just set ._bound_field_data; we must overwrite block._field_data.
+    uses_deprecated_field_data = True
+
     def __repr__(self):
         return "CachingDescriptorSystem{!r}".format((
             self.modulestore,
@@ -177,11 +183,6 @@ class CachingDescriptorSystem(MakoDescriptorSystem, EditInfoRuntimeMixin):  # li
             [str(key) for key in self.module_data.keys()],
             self.default_class,
         ))
-    
-    # This CachingDescriptorSystem runtime sets block._field_data on each block via construct_xblock_from_class(),
-    # rather than the newer approach of providing a "field-data" service via runtime.service(). As a result, during
-    # bind_for_student() we can't just set ._bound_field_data; we must overwrite block._field_data.
-    uses_deprecated_field_data = True
 
     def __init__(self, modulestore, course_key, module_data, default_class, **kwargs):
         """

xmodule/x_module.py

@@ -429,13 +429,6 @@ class XModuleMixin(XModuleFields, XBlock):
         self.save()
         return self._field_data._kvs  # pylint: disable=protected-access
 
-    def _unwrapped_field_data(self):
-        """
-        This property gets the field-data service before we wrap it in user-specifc wrappers during bind_for_student,
-        e.g. the LmsFieldData or OverrideFieldData classes.
-        """
-        return self.runtime.service(self, 'field-data-unbound')
-
     def add_aside(self, aside):
         """
         save connected asides