cablegates/oxdb/backend/fields.py
2009-12-31 16:04:32 +01:00

47 lines
1.4 KiB
Python

from django.db import models
from django.utils import simplejson as json
class DictField(models.TextField):
"""DictField is a textfield that contains JSON-serialized dictionaries."""
# Used so to_python() is called
__metaclass__ = models.SubfieldBase
def to_python(self, value):
"""Convert our string value to python after we load it from the DB"""
if isinstance(value, dict):
return value
value = json.loads(value)
assert isinstance(value, dict)
return value
def get_db_prep_save(self, value):
"""Convert our JSON object to a string before we save"""
assert isinstance(value, dict)
value = json.dumps(value)
return super(DictField, self).get_db_prep_save(value)
class TupleField(models.TextField):
"""TupleField is a textfield that contains JSON-serialized tuples."""
# Used so to_python() is called
__metaclass__ = models.SubfieldBase
def to_python(self, value):
"""Convert our string value to JSON after we load it from the DB"""
if isinstance(value, tuple):
return value
value = json.loads(value)
assert isinstance(value, list)
return tuple(value)
def get_db_prep_save(self, value):
"""Convert our JSON object to a string before we save"""
assert isinstance(value, tuple)
value = json.dumps(value)
return super(TupleField, self).get_db_prep_save(value)