def get_form_submissions_grouped_by_field(xform, field, name=None):
"""Number of submissions grouped by field"""
query = {}
mongo_field = _encode_for_mongo(field)
query[ParsedInstance.USERFORM_ID] =\
u'%s_%s' % (xform.user.username, xform.id_string)
query[mongo_field] = {"$exists": True}
# check if requested field a datetime str
record = xform_instances.find_one(query, {mongo_field: 1})
if not record:
raise ValueError(_(u"Field '%s' does not exist." % field))
group = {"count": {"$sum": 1}}
group["_id"] = _get_id_for_type(record, mongo_field)
field_name = field if name is None else name
pipeline = [
{
"$group": group
},
{
"$sort": {"_id": 1}
},
{
"$project": {
field_name: "$_id",
"count": 1
}
}
]
kargs = {
'query': query,
'pipeline': pipeline
}
records = ParsedInstance.mongo_aggregate(**kargs)
# delete mongodb's _id field from records
# TODO: is there an elegant way to do this? should we remove the field?
for record in records:
del record['_id']
return records
