import json
from django import forms
from django.utils.translation import gettext_lazy as _
__all__ = ['JSONField']
class InvalidJSONInput(str):
pass
class JSONString(str):
pass
[文档]class JSONField(forms.CharField):
default_error_messages = {
'invalid': _("'%(value)s' value must be valid JSON."),
}
widget = forms.Textarea
def to_python(self, value):
if self.disabled:
return value
if value in self.empty_values:
return None
elif isinstance(value, (list, dict, int, float, JSONString)):
return value
try:
converted = json.loads(value)
except json.JSONDecodeError:
raise forms.ValidationError(
self.error_messages['invalid'],
code='invalid',
params={'value': value},
)
if isinstance(converted, str):
return JSONString(converted)
else:
return converted
def bound_data(self, data, initial):
if self.disabled:
return initial
try:
return json.loads(data)
except json.JSONDecodeError:
return InvalidJSONInput(data)
def prepare_value(self, value):
if isinstance(value, InvalidJSONInput):
return value
return json.dumps(value)
def has_changed(self, initial, data):
if super().has_changed(initial, data):
return True
# For purposes of seeing whether something has changed, True isn't the
# same as 1 and the order of keys doesn't matter.
data = self.to_python(data)
return json.dumps(initial, sort_keys=True) != json.dumps(data, sort_keys=True)
8月 23, 2019