mirror of https://github.com/django/django.git
72 lines
2.1 KiB
Python
72 lines
2.1 KiB
Python
from django.core.exceptions import FieldError
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from django.db import models
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from django.utils import simplejson as json
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from django.utils.encoding import force_unicode
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class Small(object):
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"""
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A simple class to show that non-trivial Python objects can be used as
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attributes.
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"""
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def __init__(self, first, second):
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self.first, self.second = first, second
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def __unicode__(self):
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return u'%s%s' % (force_unicode(self.first), force_unicode(self.second))
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def __str__(self):
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return unicode(self).encode('utf-8')
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class SmallField(models.Field):
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"""
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Turns the "Small" class into a Django field. Because of the similarities
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with normal character fields and the fact that Small.__unicode__ does
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something sensible, we don't need to implement a lot here.
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"""
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__metaclass__ = models.SubfieldBase
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def __init__(self, *args, **kwargs):
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kwargs['max_length'] = 2
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super(SmallField, self).__init__(*args, **kwargs)
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def get_internal_type(self):
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return 'CharField'
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def to_python(self, value):
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if isinstance(value, Small):
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return value
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return Small(value[0], value[1])
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def get_db_prep_save(self, value):
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return unicode(value)
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def get_db_prep_lookup(self, lookup_type, value):
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if lookup_type == 'exact':
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return force_unicode(value)
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if lookup_type == 'in':
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return [force_unicode(v) for v in value]
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if lookup_type == 'isnull':
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return []
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raise FieldError('Invalid lookup type: %r' % lookup_type)
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class JSONField(models.TextField):
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__metaclass__ = models.SubfieldBase
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description = ("JSONField automatically serializes and desializes values to "
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"and from JSON.")
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def to_python(self, value):
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if not value:
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return None
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if isinstance(value, basestring):
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value = json.loads(value)
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return value
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def get_db_prep_save(self, value):
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if value is None:
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return None
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return json.dumps(value)
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