70 lines
2.2 KiB
Python
70 lines
2.2 KiB
Python
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from django.db import models
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from django.db.models import OneToOneField
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from django.utils import simplejson as json
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from django.core.serializers.json import DjangoJSONEncoder
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from django.db.models.fields.related import SingleRelatedObjectDescriptor
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class AutoSingleRelatedObjectDescriptor(SingleRelatedObjectDescriptor):
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def __get__(self, instance, instance_type=None):
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try:
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return super(AutoSingleRelatedObjectDescriptor, self).__get__(instance, instance_type)
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except self.related.model.DoesNotExist:
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obj = self.related.model(**{self.related.field.name: instance})
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obj.save()
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return obj
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class AutoOneToOneField(OneToOneField):
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'''
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OneToOneField creates related object on first call if it doesnt exist yet.
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Use it instead of original OneToOne field.
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example:
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class MyProfile(models.Model):
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user = AutoOneToOneField(User, primary_key=True)
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home_page = models.URLField(max_length=255, blank=True)
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icq = models.IntegerField(max_length=255, null=True)
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'''
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def contribute_to_related_class(self, cls, related):
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setattr(cls, related.get_accessor_name(), AutoSingleRelatedObjectDescriptor(related))
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class JSONField(models.TextField):
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"""
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JSONField is a generic textfield that neatly serializes/unserializes
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JSON objects seamlessly.
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Django snippet #1478
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example:
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class Page(models.Model):
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data = JSONField(blank=True, null=True)
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page = Page.objects.get(pk=5)
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page.data = {'title': 'test', 'type': 3}
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page.save()
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"""
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__metaclass__ = models.SubfieldBase
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def to_python(self, value):
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if value == "":
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return None
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try:
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if isinstance(value, basestring):
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return json.loads(value)
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except ValueError:
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pass
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return value
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def get_db_prep_save(self, value, *args, **kwargs):
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if value == "":
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return None
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if isinstance(value, dict):
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value = json.dumps(value, cls=DjangoJSONEncoder)
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return super(JSONField, self).get_db_prep_save(value, *args, **kwargs)
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