Created CommaSeparatedOrList field

New CommaSeparatedOrListField type which accepts a comma-separated
string (and splits it into a list) or a list input.  Useful for
handling input from the web interface as well as from the Python
client in either form.

gracedb/superevents/api/fields.py

 from rest_framework import fields
 
+import six
+import logging
+logger = logging.getLogger(__name__)
+
+
 class CustomHiddenDefault(fields.CurrentUserDefault):
     context_key = None
 
@@ -37,3 +42,25 @@ class ParentObjectDefault(CustomHiddenDefault):
                 value = value()
             #value = serializer_field.context['view'].get_parent()
         return value
+
+
+class CommaSeparatedOrListField(fields.ListField):
+    default_style = {'base_template': 'input.html'}
+
+    def __init__(self, *args, **kwargs):
+        super(CommaSeparatedOrListField, self).__init__(*args, **kwargs)
+        # Set form style for browsable API
+        self.style = kwargs.get('style', self.default_style)
+
+    def to_internal_value(self, data):
+        # Empirical tests with HTML forms indicate that if we enter
+        # something like 1,2,3 in a form, we will get something like
+        # [u'1,2,3'] here.  So if we get input like that, we convert it
+        # to [u'1', u'2', u'3'], then pass it to the base class's
+        # to_internal_value() method. Might not be safe for cases where
+        # a list contains CharFields which might have commas in them.
+        if (isinstance(data, list) and len(data) == 1 and
+            isinstance(data[0], six.string_types)):
+            data = data[0].split(',')
+        return super(CommaSeparatedOrListField, self).to_internal_value(data)
+

gracedb/superevents/api/serializers.py

@@ -5,7 +5,7 @@ from django.conf import settings
 from ..models import Superevent, Labelling, Log, VOEvent, EMObservation, \
     EMFootprint
 
-from .fields import ParentObjectDefault
+from .fields import ParentObjectDefault, CommaSeparatedOrListField
 from .settings import SUPEREVENT_LOOKUP_FIELD
 
 from events.models import Event, Label, Tag, EMGroup
@@ -14,6 +14,7 @@ from events.api.fields import EventGraceidField
 
 UserModel = get_user_model()
 
+import os
 import functools
 import logging
 logger = logging.getLogger(__name__)
@@ -448,17 +449,17 @@ class SupereventEMObservationSerializer(serializers.ModelSerializer):
         default=serializers.CurrentUserDefault())
     superevent = serializers.HiddenField(write_only=True,
         default=ParentObjectDefault(context_key='superevent'))
-    ra_list = serializers.ListField(child=serializers.FloatField(),
+    ra_list = CommaSeparatedOrListField(child=serializers.FloatField(),
         write_only=True)
-    dec_list = serializers.ListField(child=serializers.FloatField(),
+    dec_list = CommaSeparatedOrListField(child=serializers.FloatField(),
         write_only=True)
-    ra_width_list = serializers.ListField(child=serializers.FloatField(),
+    ra_width_list = CommaSeparatedOrListField(child=serializers.FloatField(),
         write_only=True)
-    dec_width_list = serializers.ListField(child=serializers.FloatField(),
+    dec_width_list = CommaSeparatedOrListField(child=serializers.FloatField(),
         write_only=True)
-    start_time_list = serializers.ListField(child=serializers.DateTimeField(),
-        write_only=True)
-    duration_list = serializers.ListField(
+    start_time_list = CommaSeparatedOrListField(
+        child=serializers.DateTimeField(), write_only=True)
+    duration_list = CommaSeparatedOrListField(
         child=serializers.IntegerField(min_value=0), write_only=True)
 
     class Meta: