django - GeoDjango: transform SRID in DRF Serializer -

i writing api using osm db, regular db, drf3 , django-rest-framework-gis.

the osm db using srid 900913, api output coordinates according srid 4326. achievable using transform(srid=4326) on geoquerysets, unfortunately not option in case (explained why further down).

of understand, should able specify srid in field definition of model so:

class polygon(models.model):     osm_id = models.autofield(primary_key=true)     name = models.charfield(null=true)     way = models.polygonfield(null=true, srid=4326)     admin_level = models.charfield(default='2', null=true)      objects = models.geomanager()      class meta:         db_table = 'osm_poly_lu' 

but api keeps returning polygons coordinates in 900913 format.

do understand correctly; should able set srid on polygon field 4326 django automatically convert dbs 900913? if so, guess must missing something; ideas of may wrong? feel true newbie in area - appreciated.

the reason why can not use transform() on querysets:

what doing querying member table, , member model regular model. have relation osm polygon table (field called osm_id_origin) , geodjango model. when serialize member drf3 serializer, have nested serializer in member serializer serializes osm_id_origin field in member model geojson. nested serializer using creating geojson subclass of django-rest-framework-gis serializer geofeaturemodelserializer. since query member model, regular queryset, can not run transform(srid=4326) on it.