replaced str_to_yes_no for str_to_yes_no_null

smash/web/api_views/subject.py

@@ -7,7 +7,7 @@ from django.db.models import Q
 from django.http import JsonResponse
 from django.urls import reverse
 
-from web.api_views.serialization_utils import bool_to_yes_no, flying_team_to_str, location_to_str, add_column, \
+from web.api_views.serialization_utils import str_to_yes_no_null, bool_to_yes_no, flying_team_to_str, location_to_str, add_column, \
     serialize_date, serialize_datetime, get_filters_for_data_table_request, virus_test_to_str, str_to_yes_no
 from web.models import ConfigurationItem, StudySubject, Visit, Appointment, Subject, SubjectColumns, StudyColumns, \
     Study, ContactAttempt
@@ -636,7 +636,7 @@ def serialize_subject(study_subject):
                 val = ''
             result[get_study_subject_field_id(field_value.study_subject_field)] = val
         elif field_value.study_subject_field.type == CUSTOM_FIELD_TYPE_BOOLEAN:
-            result[get_study_subject_field_id(field_value.study_subject_field)] = str_to_yes_no(field_value.value)
+            result[get_study_subject_field_id(field_value.study_subject_field)] = str_to_yes_no_null(field_value.value)
         elif field_value.study_subject_field.type == CUSTOM_FIELD_TYPE_DATE:
             result[get_study_subject_field_id(field_value.study_subject_field)] = field_value.value
         elif field_value.study_subject_field.type == CUSTOM_FIELD_TYPE_SELECT_LIST: