python-ox/ox/django/fields.py

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2010-11-23 09:23:40 +00:00
import time
from django.db import models
from django.utils import simplejson as json
def to_json(python_object):
if isinstance(python_object, time.struct_time):
return {'__class__': 'time.asctime',
'__value__': time.asctime(python_object)}
if isinstance(python_object, bytes):
return {'__class__': 'bytes',
'__value__': list(python_object)}
raise TypeError(repr(python_object) + ' is not JSON serializable')
def from_json(json_object):
if '__class__' in json_object:
if json_object['__class__'] == 'time.asctime':
return time.strptime(json_object['__value__'])
if json_object['__class__'] == 'bytes':
return bytes(json_object['__value__'])
return json_object
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
try:
value = json.loads(value, object_hook=from_json)
except: #this is required to load fixtures
value = eval(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, default=to_json)
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
try:
value = json.loads(value, object_hook=from_json)
except: #this is required to load fixtures
value = eval(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, default=to_json)
return super(TupleField, self).get_db_prep_save(value)
try:
from south.modelsinspector import add_introspection_rules
add_introspection_rules([], ["^oxdjango\.fields\.DictField"])
add_introspection_rules([], ["^oxdjango\.fields\.TupleField"])
except:
pass