Restored `discussion_id` XBlock field.

common/lib/xblock/discussion/discussion_forum/discussion_forum.py

@@ -4,6 +4,8 @@ from xblock.core import XBlock
 from xblock.fields import Scope, String
 from xblock.fragment import Fragment
 
+from uuid import uuid4
+
 from .utils import (
     render_template,
     render_mako_template,
@@ -17,6 +19,9 @@ log = logging.getLogger(__name__)
 @XBlock.needs('discussion')
 class DiscussionXBlock(XBlock):
     """ Provides functionality similar to discussion XModule in inline mode """
+    FIELDS_TO_INIT = ('discussion_id',)
+
+    discussion_id = String(scope=Scope.settings, default=lambda: uuid4().hex)
     display_name = String(
         display_name="Display Name",
         help="Display name for this module",
@@ -43,13 +48,6 @@ class DiscussionXBlock(XBlock):
     sort_key = String(scope=Scope.settings)
 
     @property
-    def discussion_id(self):
-        """
-        :return: int discussion id
-        """
-        return self.scope_ids.usage_id.block_id
-
-    @property
     def course_id(self):
         """
         :return: int course id