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32d4db66b9
As suggested by Anssi. This has the slightly strange side effect of passing the expression to Expression.convert_value has the expression passed back to it, but it allows more complex patterns of expressions.
64 lines
1.7 KiB
Python
64 lines
1.7 KiB
Python
import random
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import string
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from django.db import models
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from django.utils import six
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from django.utils.encoding import python_2_unicode_compatible
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@python_2_unicode_compatible
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class MyWrapper(object):
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def __init__(self, value):
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self.value = value
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def __repr__(self):
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return "<%s: %s>" % (self.__class__.__name__, self.value)
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def __str__(self):
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return self.value
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def __eq__(self, other):
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if isinstance(other, self.__class__):
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return self.value == other.value
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return self.value == other
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class MyAutoField(models.CharField):
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def __init__(self, *args, **kwargs):
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kwargs['max_length'] = 10
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super(MyAutoField, self).__init__(*args, **kwargs)
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def pre_save(self, instance, add):
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value = getattr(instance, self.attname, None)
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if not value:
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value = MyWrapper(''.join(random.sample(string.ascii_lowercase, 10)))
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setattr(instance, self.attname, value)
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return value
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def to_python(self, value):
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if not value:
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return
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if not isinstance(value, MyWrapper):
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value = MyWrapper(value)
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return value
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def from_db_value(self, value, expression, connection, context):
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if not value:
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return
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return MyWrapper(value)
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def get_db_prep_save(self, value, connection):
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if not value:
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return
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if isinstance(value, MyWrapper):
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return six.text_type(value)
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return value
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def get_db_prep_value(self, value, connection, prepared=False):
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if not value:
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return
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if isinstance(value, MyWrapper):
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return six.text_type(value)
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return value
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