60 lines
1.8 KiB
Python
60 lines
1.8 KiB
Python
import json
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from django import forms
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from django.core.exceptions import ValidationError
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from django.utils import six
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from django.utils.translation import ugettext_lazy as _
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__all__ = ['HStoreField']
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class HStoreField(forms.CharField):
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"""
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A field for HStore data which accepts dictionary JSON input.
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"""
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widget = forms.Textarea
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default_error_messages = {
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'invalid_json': _('Could not load JSON data.'),
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'invalid_format': _('Input must be a JSON dictionary.'),
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}
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def prepare_value(self, value):
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if isinstance(value, dict):
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return json.dumps(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, dict):
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try:
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value = json.loads(value)
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except ValueError:
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raise ValidationError(
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self.error_messages['invalid_json'],
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code='invalid_json',
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)
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if not isinstance(value, dict):
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raise ValidationError(
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self.error_messages['invalid_format'],
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code='invalid_format',
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)
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# Cast everything to strings for ease.
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for key, val in value.items():
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if val is not None:
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val = six.text_type(val)
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value[key] = val
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return value
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def has_changed(self, initial, data):
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"""
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Return True if data differs from initial.
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"""
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# For purposes of seeing whether something has changed, None is
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# the same as an empty dict, if the data or initial value we get
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# is None, replace it w/ {}.
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initial_value = self.to_python(initial)
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return super(HStoreField, self).has_changed(initial_value, data)
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