Fix to save text of material

courses/course_material/views.py

@@ -20,6 +20,11 @@ class CourseMaterialViewSet(viewsets.ModelViewSet):
             self.kwargs['course'] = obj.course
         return super(CourseMaterialViewSet, self).pre_save(obj)
 
+    def perform_update(self, serializer):
+        instance = CourseMaterial.objects.get(id=self.request.data['id'])
+        instance.text = self.request.data['text']
+        instance.save()
+
 
 class CourseMaterialFileViewSet(viewsets.ModelViewSet):
     model = CourseMaterialFile