Revert "Revert "refactor: move xmodule folder to root""

xmodule/modulestore/mongoengine_fields.py

@@ -0,0 +1,90 @@
+"""
+Custom field types for mongoengine
+"""
+
+
+import mongoengine
+
+from opaque_keys.edx.keys import CourseKey, UsageKey
+from opaque_keys.edx.locations import Location
+
+
+class CourseKeyField(mongoengine.StringField):
+    """
+    Serializes and deserializes CourseKey's to mongo dbs which use mongoengine
+    """
+    def __init__(self, **kwargs):
+        # it'd be useful to add init args such as support_deprecated, force_deprecated
+        super().__init__(**kwargs)
+
+    def to_mongo(self, course_key):  # lint-amnesty, pylint: disable=arguments-differ
+        """
+        For now saves the course key in the deprecated form
+        """
+        assert isinstance(course_key, (type(None), CourseKey))
+        if course_key:
+            # don't call super as base.BaseField.to_mongo calls to_python() for some odd reason
+            return str(course_key)
+        else:
+            return None
+
+    def to_python(self, course_key):  # lint-amnesty, pylint: disable=arguments-differ
+        """
+        Deserialize to a CourseKey instance
+        """
+        # calling super b/c it decodes utf (and doesn't have circularity of from_python)
+        course_key = super().to_python(course_key)
+        assert isinstance(course_key, (type(None), (str,), CourseKey))
+        if course_key == '':
+            return None
+        if isinstance(course_key, str):
+            return CourseKey.from_string(course_key)
+        else:
+            return course_key
+
+    def validate(self, value):
+        assert isinstance(value, (type(None), str, CourseKey))
+        if isinstance(value, CourseKey):
+            return super().validate(str(value))
+        else:
+            return super().validate(value)
+
+    def prepare_query_value(self, _opt, value):
+        return self.to_mongo(value)
+
+
+class UsageKeyField(mongoengine.StringField):
+    """
+    Represent a UsageKey as a single string in Mongo
+    """
+    def to_mongo(self, location):  # lint-amnesty, pylint: disable=arguments-differ
+        """
+        For now saves the usage key in the deprecated location i4x/c4x form
+        """
+        assert isinstance(location, (type(None), UsageKey))
+        if location is None:
+            return None
+        return super().to_mongo(str(location))
+
+    def to_python(self, location):  # lint-amnesty, pylint: disable=arguments-differ
+        """
+        Deserialize to a UsageKey instance: for now it's a location missing the run
+        """
+        assert isinstance(location, (type(None), str, UsageKey))
+        if location == '':
+            return None
+        if isinstance(location, str):
+            location = super().to_python(location)
+            return Location.from_string(location)
+        else:
+            return location
+
+    def validate(self, value):
+        assert isinstance(value, (type(None), str, UsageKey))
+        if isinstance(value, UsageKey):
+            return super().validate(str(value))
+        else:
+            return super().validate(value)
+
+    def prepare_query_value(self, _opt, value):
+        return self.to_mongo(value)