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Use forms.TextArea for custom JSON field in Django admin site

I am using a Django custom field to represent JSON encoded data:

class JSONField(models.TextField):
    __metaclass__ = models.SubfieldBase

    def to_python(self, value):
        if value == "":
            return None

        try:
            if isinstance(value, basestring):
                return json_decode(value)
        except ValueError:
            pass

        return value

    def get_prep_value(self, value):
        if value == "":
            return None
        if isinstance(value, dict) or isinstance(value, dict):
            value = json_encode(value)
            return super(JSONField, self).get_prep_value(value)

    def value_to_string(self, obj):
        value = self._get_val_from_obj(obj)
        return self.get_db_prep_value(value,connection=None)

The field itself works great. However, editing through the admin site is not possible, since the string from the database is JSON-decoded and converted to a dictionary, so when rendering the admin site, the actual JSON string from the database is displayed (for example, {"foo": "bar"}), but its vocabulary representation (for example, {u'foo ': u'bar'}).

Obviously, this leads to problems when saving the database object, since the representation of the dictionary string is not a valid JSON string.

, , - , (.. , ), Python, to_python.

, , json_encode - ?

+5
1

value_from_object . , , simplejson :

from django.utils import simplejson as json
from django.core.serializers.json import DjangoJSONEncoder

class JSONField(models.TextField):
....

    def value_from_object(self, obj):
        return json.dumps(super(JSONField, self).value_from_object(obj))
+4

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