django-multiselectfield/multiselectfield/db/fields.py

159 lines
6.1 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (c) 2012 by Pablo Martín <goinnn@gmail.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this programe. If not, see <http://www.gnu.org/licenses/>.
import sys
from django import VERSION
from django.db import models
from django.utils.text import capfirst
from django.core import exceptions
from ..forms.fields import MultiSelectFormField, MinChoicesValidator, MaxChoicesValidator
from ..utils import get_max_length
from ..validators import MaxValueMultiFieldValidator
if sys.version_info < (3,):
string_type = unicode # noqa: F821
else:
string_type = str
# Code from six egg https://bitbucket.org/gutworth/six/src/a3641cb211cc360848f1e2dd92e9ae6cd1de55dd/six.py?at=default
def add_metaclass(metaclass):
"""Class decorator for creating a class with a metaclass."""
def wrapper(cls):
orig_vars = cls.__dict__.copy()
orig_vars.pop('__dict__', None)
orig_vars.pop('__weakref__', None)
for slots_var in orig_vars.get('__slots__', ()):
orig_vars.pop(slots_var)
return metaclass(cls.__name__, cls.__bases__, orig_vars)
return wrapper
class MultiSelectField(models.CharField):
""" Choice values can not contain commas. """
def __init__(self, *args, **kwargs):
self.min_choices = kwargs.pop('min_choices', None)
self.max_choices = kwargs.pop('max_choices', None)
super(MultiSelectField, self).__init__(*args, **kwargs)
self.max_length = get_max_length(self.choices, self.max_length)
self.validators[0] = MaxValueMultiFieldValidator(self.max_length)
if self.min_choices is not None:
self.validators.append(MinChoicesValidator(self.min_choices))
if self.max_choices is not None:
self.validators.append(MaxChoicesValidator(self.max_choices))
def get_choices_default(self):
return self.get_choices(include_blank=False)
def get_choices_selected(self, arr_choices):
named_groups = arr_choices and isinstance(arr_choices[0][1], (list, tuple))
choices_selected = []
if named_groups:
for choice_group_selected in arr_choices:
for choice_selected in choice_group_selected[1]:
choices_selected.append(string_type(choice_selected[0]))
else:
for choice_selected in arr_choices:
choices_selected.append(string_type(choice_selected[0]))
return choices_selected
def value_to_string(self, obj):
value = self._get_val_from_obj(obj)
return self.get_prep_value(value)
def validate(self, value, model_instance):
arr_choices = self.get_choices_selected(self.get_choices_default())
for opt_select in value:
if (opt_select not in arr_choices):
if VERSION >= (1, 6):
raise exceptions.ValidationError(self.error_messages['invalid_choice'] % {"value": value})
else:
raise exceptions.ValidationError(self.error_messages['invalid_choice'] % value)
def get_default(self):
default = super(MultiSelectField, self).get_default()
if isinstance(default, int):
default = string_type(default)
return default
def formfield(self, **kwargs):
defaults = {'required': not self.blank,
'label': capfirst(self.verbose_name),
'help_text': self.help_text,
'choices': self.choices,
'max_length': self.max_length,
'max_choices': self.max_choices}
if self.has_default():
defaults['initial'] = self.get_default()
defaults.update(kwargs)
return MultiSelectFormField(**defaults)
def get_prep_value(self, value):
return '' if value is None else ",".join(value)
def get_db_prep_value(self, value, connection, prepared=False):
if not prepared and not isinstance(value, string_type):
value = self.get_prep_value(value)
return value
def to_python(self, value):
if value:
return value if isinstance(value, list) else value.split(',')
return []
def from_db_value(self, value, expression, connection, context):
if value is None:
return value
return self.to_python(value)
def contribute_to_class(self, cls, name):
super(MultiSelectField, self).contribute_to_class(cls, name)
if self.choices:
def get_list(obj):
fieldname = name
choicedict = dict(self.choices)
display = []
if getattr(obj, fieldname):
for value in getattr(obj, fieldname):
item_display = choicedict.get(value, None)
if item_display is None:
try:
item_display = choicedict.get(int(value), value)
except (ValueError, TypeError):
item_display = value
display.append(string_type(item_display))
return display
def get_display(obj):
return ", ".join(get_list(obj))
setattr(cls, 'get_%s_list' % self.name, get_list)
setattr(cls, 'get_%s_display' % self.name, get_display)
if VERSION < (1, 8):
MultiSelectField = add_metaclass(models.SubfieldBase)(MultiSelectField)
try:
from south.modelsinspector import add_introspection_rules
add_introspection_rules([], ['^multiselectfield\.db.fields\.MultiSelectField'])
except ImportError:
pass