Skip to content

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
1321 lines (1144 sloc) 55.376 kb
"""
Helper functions for creating Form classes from Django models
and database field objects.
"""
from __future__ import unicode_literals
from collections import OrderedDict
from itertools import chain
from django.core.exceptions import (
NON_FIELD_ERRORS, FieldError, ImproperlyConfigured, ValidationError,
)
from django.forms.fields import ChoiceField, Field
from django.forms.forms import BaseForm, DeclarativeFieldsMetaclass
from django.forms.formsets import BaseFormSet, formset_factory
from django.forms.utils import ErrorList
from django.forms.widgets import (
HiddenInput, MultipleHiddenInput, SelectMultiple,
)
from django.utils import six
from django.utils.encoding import force_text, smart_text
from django.utils.text import capfirst, get_text_list
from django.utils.translation import ugettext, ugettext_lazy as _
__all__ = (
'ModelForm', 'BaseModelForm', 'model_to_dict', 'fields_for_model',
'save_instance', 'ModelChoiceField', 'ModelMultipleChoiceField',
'ALL_FIELDS', 'BaseModelFormSet', 'modelformset_factory',
'BaseInlineFormSet', 'inlineformset_factory', 'modelform_factory',
)
ALL_FIELDS = '__all__'
def construct_instance(form, instance, fields=None, exclude=None):
"""
Constructs and returns a model instance from the bound ``form``'s
``cleaned_data``, but does not save the returned instance to the
database.
"""
from django.db import models
opts = instance._meta
cleaned_data = form.cleaned_data
file_field_list = []
for f in opts.fields:
if not f.editable or isinstance(f, models.AutoField) \
or f.name not in cleaned_data:
continue
if fields is not None and f.name not in fields:
continue
if exclude and f.name in exclude:
continue
# Defer saving file-type fields until after the other fields, so a
# callable upload_to can use the values from other fields.
if isinstance(f, models.FileField):
file_field_list.append(f)
else:
f.save_form_data(instance, cleaned_data[f.name])
for f in file_field_list:
f.save_form_data(instance, cleaned_data[f.name])
return instance
def save_instance(form, instance, fields=None, fail_message='saved',
commit=True, exclude=None, construct=True):
"""
Saves bound Form ``form``'s cleaned_data into model instance ``instance``.
If commit=True, then the changes to ``instance`` will be saved to the
database. Returns ``instance``.
If construct=False, assume ``instance`` has already been constructed and
just needs to be saved.
"""
if construct:
instance = construct_instance(form, instance, fields, exclude)
opts = instance._meta
if form.errors:
raise ValueError("The %s could not be %s because the data didn't"
" validate." % (opts.object_name, fail_message))
# Wrap up the saving of m2m data as a function.
def save_m2m():
cleaned_data = form.cleaned_data
# Note that for historical reasons we want to include also
# virtual_fields here. (GenericRelation was previously a fake
# m2m field).
for f in chain(opts.many_to_many, opts.virtual_fields):
if not hasattr(f, 'save_form_data'):
continue
if fields and f.name not in fields:
continue
if exclude and f.name in exclude:
continue
if f.name in cleaned_data:
f.save_form_data(instance, cleaned_data[f.name])
if commit:
# If we are committing, save the instance and the m2m data immediately.
instance.save()
save_m2m()
else:
# We're not committing. Add a method to the form to allow deferred
# saving of m2m data.
form.save_m2m = save_m2m
return instance
# ModelForms #################################################################
def model_to_dict(instance, fields=None, exclude=None):
"""
Returns a dict containing the data in ``instance`` suitable for passing as
a Form's ``initial`` keyword argument.
``fields`` is an optional list of field names. If provided, only the named
fields will be included in the returned dict.
``exclude`` is an optional list of field names. If provided, the named
fields will be excluded from the returned dict, even if they are listed in
the ``fields`` argument.
"""
# avoid a circular import
from django.db.models.fields.related import ManyToManyField
opts = instance._meta
data = {}
for f in chain(opts.concrete_fields, opts.virtual_fields, opts.many_to_many):
if not getattr(f, 'editable', False):
continue
if fields and f.name not in fields:
continue
if exclude and f.name in exclude:
continue
if isinstance(f, ManyToManyField):
# If the object doesn't have a primary key yet, just use an empty
# list for its m2m fields. Calling f.value_from_object will raise
# an exception.
if instance.pk is None:
data[f.name] = []
else:
# MultipleChoiceWidget needs a list of pks, not object instances.
qs = f.value_from_object(instance)
if qs._result_cache is not None:
data[f.name] = [item.pk for item in qs]
else:
data[f.name] = list(qs.values_list('pk', flat=True))
else:
data[f.name] = f.value_from_object(instance)
return data
def fields_for_model(model, fields=None, exclude=None, widgets=None,
formfield_callback=None, localized_fields=None,
labels=None, help_texts=None, error_messages=None,
field_classes=None):
"""
Returns a ``OrderedDict`` containing form fields for the given model.
``fields`` is an optional list of field names. If provided, only the named
fields will be included in the returned fields.
``exclude`` is an optional list of field names. If provided, the named
fields will be excluded from the returned fields, even if they are listed
in the ``fields`` argument.
``widgets`` is a dictionary of model field names mapped to a widget.
``formfield_callback`` is a callable that takes a model field and returns
a form field.
``localized_fields`` is a list of names of fields which should be localized.
``labels`` is a dictionary of model field names mapped to a label.
``help_texts`` is a dictionary of model field names mapped to a help text.
``error_messages`` is a dictionary of model field names mapped to a
dictionary of error messages.
``field_classes`` is a dictionary of model field names mapped to a form
field class.
"""
field_list = []
ignored = []
opts = model._meta
# Avoid circular import
from django.db.models.fields import Field as ModelField
sortable_virtual_fields = [f for f in opts.virtual_fields
if isinstance(f, ModelField)]
for f in sorted(chain(opts.concrete_fields, sortable_virtual_fields, opts.many_to_many)):
if not getattr(f, 'editable', False):
continue
if fields is not None and f.name not in fields:
continue
if exclude and f.name in exclude:
continue
kwargs = {}
if widgets and f.name in widgets:
kwargs['widget'] = widgets[f.name]
if localized_fields == ALL_FIELDS or (localized_fields and f.name in localized_fields):
kwargs['localize'] = True
if labels and f.name in labels:
kwargs['label'] = labels[f.name]
if help_texts and f.name in help_texts:
kwargs['help_text'] = help_texts[f.name]
if error_messages and f.name in error_messages:
kwargs['error_messages'] = error_messages[f.name]
if field_classes and f.name in field_classes:
kwargs['form_class'] = field_classes[f.name]
if formfield_callback is None:
formfield = f.formfield(**kwargs)
elif not callable(formfield_callback):
raise TypeError('formfield_callback must be a function or callable')
else:
formfield = formfield_callback(f, **kwargs)
if formfield:
field_list.append((f.name, formfield))
else:
ignored.append(f.name)
field_dict = OrderedDict(field_list)
if fields:
field_dict = OrderedDict(
[(f, field_dict.get(f)) for f in fields
if ((not exclude) or (exclude and f not in exclude)) and (f not in ignored)]
)
return field_dict
class ModelFormOptions(object):
def __init__(self, options=None):
self.model = getattr(options, 'model', None)
self.fields = getattr(options, 'fields', None)
self.exclude = getattr(options, 'exclude', None)
self.widgets = getattr(options, 'widgets', None)
self.localized_fields = getattr(options, 'localized_fields', None)
self.labels = getattr(options, 'labels', None)
self.help_texts = getattr(options, 'help_texts', None)
self.error_messages = getattr(options, 'error_messages', None)
self.field_classes = getattr(options, 'field_classes', None)
class ModelFormMetaclass(DeclarativeFieldsMetaclass):
def __new__(mcs, name, bases, attrs):
formfield_callback = attrs.pop('formfield_callback', None)
new_class = super(ModelFormMetaclass, mcs).__new__(mcs, name, bases, attrs)
if bases == (BaseModelForm,):
return new_class
opts = new_class._meta = ModelFormOptions(getattr(new_class, 'Meta', None))
# We check if a string was passed to `fields` or `exclude`,
# which is likely to be a mistake where the user typed ('foo') instead
# of ('foo',)
for opt in ['fields', 'exclude', 'localized_fields']:
value = getattr(opts, opt)
if isinstance(value, six.string_types) and value != ALL_FIELDS:
msg = ("%(model)s.Meta.%(opt)s cannot be a string. "
"Did you mean to type: ('%(value)s',)?" % {
'model': new_class.__name__,
'opt': opt,
'value': value,
})
raise TypeError(msg)
if opts.model:
# If a model is defined, extract form fields from it.
if opts.fields is None and opts.exclude is None:
raise ImproperlyConfigured(
"Creating a ModelForm without either the 'fields' attribute "
"or the 'exclude' attribute is prohibited; form %s "
"needs updating." % name
)
if opts.fields == ALL_FIELDS:
# Sentinel for fields_for_model to indicate "get the list of
# fields from the model"
opts.fields = None
fields = fields_for_model(opts.model, opts.fields, opts.exclude,
opts.widgets, formfield_callback,
opts.localized_fields, opts.labels,
opts.help_texts, opts.error_messages,
opts.field_classes)
# make sure opts.fields doesn't specify an invalid field
none_model_fields = [k for k, v in six.iteritems(fields) if not v]
missing_fields = (set(none_model_fields) -
set(new_class.declared_fields.keys()))
if missing_fields:
message = 'Unknown field(s) (%s) specified for %s'
message = message % (', '.join(missing_fields),
opts.model.__name__)
raise FieldError(message)
# Override default model fields with any custom declared ones
# (plus, include all the other declared fields).
fields.update(new_class.declared_fields)
else:
fields = new_class.declared_fields
new_class.base_fields = fields
return new_class
class BaseModelForm(BaseForm):
def __init__(self, data=None, files=None, auto_id='id_%s', prefix=None,
initial=None, error_class=ErrorList, label_suffix=None,
empty_permitted=False, instance=None):
opts = self._meta
if opts.model is None:
raise ValueError('ModelForm has no model class specified.')
if instance is None:
# if we didn't get an instance, instantiate a new one
self.instance = opts.model()
object_data = {}
else:
self.instance = instance
object_data = model_to_dict(instance, opts.fields, opts.exclude)
# if initial was provided, it should override the values from instance
if initial is not None:
object_data.update(initial)
# self._validate_unique will be set to True by BaseModelForm.clean().
# It is False by default so overriding self.clean() and failing to call
# super will stop validate_unique from being called.
self._validate_unique = False
super(BaseModelForm, self).__init__(data, files, auto_id, prefix, object_data,
error_class, label_suffix, empty_permitted)
# Apply ``limit_choices_to`` to each field.
for field_name in self.fields:
formfield = self.fields[field_name]
if hasattr(formfield, 'queryset') and hasattr(formfield, 'get_limit_choices_to'):
limit_choices_to = formfield.get_limit_choices_to()
if limit_choices_to is not None:
formfield.queryset = formfield.queryset.complex_filter(limit_choices_to)
def _get_validation_exclusions(self):
"""
For backwards-compatibility, several types of fields need to be
excluded from model validation. See the following tickets for
details: #12507, #12521, #12553
"""
exclude = []
# Build up a list of fields that should be excluded from model field
# validation and unique checks.
for f in self.instance._meta.fields:
field = f.name
# Exclude fields that aren't on the form. The developer may be
# adding these values to the model after form validation.
if field not in self.fields:
exclude.append(f.name)
# Don't perform model validation on fields that were defined
# manually on the form and excluded via the ModelForm's Meta
# class. See #12901.
elif self._meta.fields and field not in self._meta.fields:
exclude.append(f.name)
elif self._meta.exclude and field in self._meta.exclude:
exclude.append(f.name)
# Exclude fields that failed form validation. There's no need for
# the model fields to validate them as well.
elif field in self._errors.keys():
exclude.append(f.name)
# Exclude empty fields that are not required by the form, if the
# underlying model field is required. This keeps the model field
# from raising a required error. Note: don't exclude the field from
# validation if the model field allows blanks. If it does, the blank
# value may be included in a unique check, so cannot be excluded
# from validation.
else:
form_field = self.fields[field]
field_value = self.cleaned_data.get(field, None)
if not f.blank and not form_field.required and field_value in form_field.empty_values:
exclude.append(f.name)
return exclude
def clean(self):
self._validate_unique = True
return self.cleaned_data
def _update_errors(self, errors):
# Override any validation error messages defined at the model level
# with those defined at the form level.
opts = self._meta
for field, messages in errors.error_dict.items():
if (field == NON_FIELD_ERRORS and opts.error_messages and
NON_FIELD_ERRORS in opts.error_messages):
error_messages = opts.error_messages[NON_FIELD_ERRORS]
elif field in self.fields:
error_messages = self.fields[field].error_messages
else:
continue
for message in messages:
if (isinstance(message, ValidationError) and
message.code in error_messages):
message.message = error_messages[message.code]
self.add_error(None, errors)
def _post_clean(self):
opts = self._meta
exclude = self._get_validation_exclusions()
# a subset of `exclude` which won't have the InlineForeignKeyField
# if we're adding a new object since that value doesn't exist
# until after the new instance is saved to the database.
construct_instance_exclude = list(exclude)
# Foreign Keys being used to represent inline relationships
# are excluded from basic field value validation. This is for two
# reasons: firstly, the value may not be supplied (#12507; the
# case of providing new values to the admin); secondly the
# object being referred to may not yet fully exist (#12749).
# However, these fields *must* be included in uniqueness checks,
# so this can't be part of _get_validation_exclusions().
for name, field in self.fields.items():
if isinstance(field, InlineForeignKeyField):
if self.cleaned_data.get(name) is not None and self.cleaned_data[name]._state.adding:
construct_instance_exclude.append(name)
exclude.append(name)
# Update the model instance with self.cleaned_data.
self.instance = construct_instance(self, self.instance, opts.fields, construct_instance_exclude)
try:
self.instance.full_clean(exclude=exclude, validate_unique=False)
except ValidationError as e:
self._update_errors(e)
# Validate uniqueness if needed.
if self._validate_unique:
self.validate_unique()
def validate_unique(self):
"""
Calls the instance's validate_unique() method and updates the form's
validation errors if any were raised.
"""
exclude = self._get_validation_exclusions()
try:
self.instance.validate_unique(exclude=exclude)
except ValidationError as e:
self._update_errors(e)
def save(self, commit=True):
"""
Saves this ``form``'s cleaned_data into model instance
``self.instance``.
If commit=True, then the changes to ``instance`` will be saved to the
database. Returns ``instance``.
"""
if self.instance.pk is None:
fail_message = 'created'
else:
fail_message = 'changed'
return save_instance(self, self.instance, self._meta.fields,
fail_message, commit, self._meta.exclude,
construct=False)
save.alters_data = True
class ModelForm(six.with_metaclass(ModelFormMetaclass, BaseModelForm)):
pass
def modelform_factory(model, form=ModelForm, fields=None, exclude=None,
formfield_callback=None, widgets=None, localized_fields=None,
labels=None, help_texts=None, error_messages=None,
field_classes=None):
"""
Returns a ModelForm containing form fields for the given model.
``fields`` is an optional list of field names. If provided, only the named
fields will be included in the returned fields. If omitted or '__all__',
all fields will be used.
``exclude`` is an optional list of field names. If provided, the named
fields will be excluded from the returned fields, even if they are listed
in the ``fields`` argument.
``widgets`` is a dictionary of model field names mapped to a widget.
``localized_fields`` is a list of names of fields which should be localized.
``formfield_callback`` is a callable that takes a model field and returns
a form field.
``labels`` is a dictionary of model field names mapped to a label.
``help_texts`` is a dictionary of model field names mapped to a help text.
``error_messages`` is a dictionary of model field names mapped to a
dictionary of error messages.
``field_classes`` is a dictionary of model field names mapped to a form
field class.
"""
# Create the inner Meta class. FIXME: ideally, we should be able to
# construct a ModelForm without creating and passing in a temporary
# inner class.
# Build up a list of attributes that the Meta object will have.
attrs = {'model': model}
if fields is not None:
attrs['fields'] = fields
if exclude is not None:
attrs['exclude'] = exclude
if widgets is not None:
attrs['widgets'] = widgets
if localized_fields is not None:
attrs['localized_fields'] = localized_fields
if labels is not None:
attrs['labels'] = labels
if help_texts is not None:
attrs['help_texts'] = help_texts
if error_messages is not None:
attrs['error_messages'] = error_messages
if field_classes is not None:
attrs['field_classes'] = field_classes
# If parent form class already has an inner Meta, the Meta we're
# creating needs to inherit from the parent's inner meta.
parent = (object,)
if hasattr(form, 'Meta'):
parent = (form.Meta, object)
Meta = type(str('Meta'), parent, attrs)
# Give this new form class a reasonable name.
class_name = model.__name__ + str('Form')
# Class attributes for the new form class.
form_class_attrs = {
'Meta': Meta,
'formfield_callback': formfield_callback
}
if (getattr(Meta, 'fields', None) is None and
getattr(Meta, 'exclude', None) is None):
raise ImproperlyConfigured(
"Calling modelform_factory without defining 'fields' or "
"'exclude' explicitly is prohibited."
)
# Instantiate type(form) in order to use the same metaclass as form.
return type(form)(class_name, (form,), form_class_attrs)
# ModelFormSets ##############################################################
class BaseModelFormSet(BaseFormSet):
"""
A ``FormSet`` for editing a queryset and/or adding new objects to it.
"""
model = None
def __init__(self, data=None, files=None, auto_id='id_%s', prefix=None,
queryset=None, **kwargs):
self.queryset = queryset
self.initial_extra = kwargs.pop('initial', None)
defaults = {'data': data, 'files': files, 'auto_id': auto_id, 'prefix': prefix}
defaults.update(kwargs)
super(BaseModelFormSet, self).__init__(**defaults)
def initial_form_count(self):
"""Returns the number of forms that are required in this FormSet."""
if not (self.data or self.files):
return len(self.get_queryset())
return super(BaseModelFormSet, self).initial_form_count()
def _existing_object(self, pk):
if not hasattr(self, '_object_dict'):
self._object_dict = {o.pk: o for o in self.get_queryset()}
return self._object_dict.get(pk)
def _get_to_python(self, field):
"""
If the field is a related field, fetch the concrete field's (that
is, the ultimate pointed-to field's) to_python.
"""
while field.rel is not None:
field = field.rel.get_related_field()
return field.to_python
def _construct_form(self, i, **kwargs):
if self.is_bound and i < self.initial_form_count():
pk_key = "%s-%s" % (self.add_prefix(i), self.model._meta.pk.name)
pk = self.data[pk_key]
pk_field = self.model._meta.pk
to_python = self._get_to_python(pk_field)
pk = to_python(pk)
kwargs['instance'] = self._existing_object(pk)
if i < self.initial_form_count() and 'instance' not in kwargs:
kwargs['instance'] = self.get_queryset()[i]
if i >= self.initial_form_count() and self.initial_extra:
# Set initial values for extra forms
try:
kwargs['initial'] = self.initial_extra[i - self.initial_form_count()]
except IndexError:
pass
return super(BaseModelFormSet, self)._construct_form(i, **kwargs)
def get_queryset(self):
if not hasattr(self, '_queryset'):
if self.queryset is not None:
qs = self.queryset
else:
qs = self.model._default_manager.get_queryset()
# If the queryset isn't already ordered we need to add an
# artificial ordering here to make sure that all formsets
# constructed from this queryset have the same form order.
if not qs.ordered:
qs = qs.order_by(self.model._meta.pk.name)
# Removed queryset limiting here. As per discussion re: #13023
# on django-dev, max_num should not prevent existing
# related objects/inlines from being displayed.
self._queryset = qs
return self._queryset
def save_new(self, form, commit=True):
"""Saves and returns a new model instance for the given form."""
return form.save(commit=commit)
def save_existing(self, form, instance, commit=True):
"""Saves and returns an existing model instance for the given form."""
return form.save(commit=commit)
def save(self, commit=True):
"""Saves model instances for every form, adding and changing instances
as necessary, and returns the list of instances.
"""
if not commit:
self.saved_forms = []
def save_m2m():
for form in self.saved_forms:
form.save_m2m()
self.save_m2m = save_m2m
return self.save_existing_objects(commit) + self.save_new_objects(commit)
save.alters_data = True
def clean(self):
self.validate_unique()
def validate_unique(self):
# Collect unique_checks and date_checks to run from all the forms.
all_unique_checks = set()
all_date_checks = set()
forms_to_delete = self.deleted_forms
valid_forms = [form for form in self.forms if form.is_valid() and form not in forms_to_delete]
for form in valid_forms:
exclude = form._get_validation_exclusions()
unique_checks, date_checks = form.instance._get_unique_checks(exclude=exclude)
all_unique_checks = all_unique_checks.union(set(unique_checks))
all_date_checks = all_date_checks.union(set(date_checks))
errors = []
# Do each of the unique checks (unique and unique_together)
for uclass, unique_check in all_unique_checks:
seen_data = set()
for form in valid_forms:
# get data for each field of each of unique_check
row_data = (form.cleaned_data[field]
for field in unique_check if field in form.cleaned_data)
# Reduce Model instances to their primary key values
row_data = tuple(d._get_pk_val() if hasattr(d, '_get_pk_val') else d
for d in row_data)
if row_data and None not in row_data:
# if we've already seen it then we have a uniqueness failure
if row_data in seen_data:
# poke error messages into the right places and mark
# the form as invalid
errors.append(self.get_unique_error_message(unique_check))
form._errors[NON_FIELD_ERRORS] = self.error_class([self.get_form_error()])
# remove the data from the cleaned_data dict since it was invalid
for field in unique_check:
if field in form.cleaned_data:
del form.cleaned_data[field]
# mark the data as seen
seen_data.add(row_data)
# iterate over each of the date checks now
for date_check in all_date_checks:
seen_data = set()
uclass, lookup, field, unique_for = date_check
for form in valid_forms:
# see if we have data for both fields
if (form.cleaned_data and form.cleaned_data[field] is not None
and form.cleaned_data[unique_for] is not None):
# if it's a date lookup we need to get the data for all the fields
if lookup == 'date':
date = form.cleaned_data[unique_for]
date_data = (date.year, date.month, date.day)
# otherwise it's just the attribute on the date/datetime
# object
else:
date_data = (getattr(form.cleaned_data[unique_for], lookup),)
data = (form.cleaned_data[field],) + date_data
# if we've already seen it then we have a uniqueness failure
if data in seen_data:
# poke error messages into the right places and mark
# the form as invalid
errors.append(self.get_date_error_message(date_check))
form._errors[NON_FIELD_ERRORS] = self.error_class([self.get_form_error()])
# remove the data from the cleaned_data dict since it was invalid
del form.cleaned_data[field]
# mark the data as seen
seen_data.add(data)
if errors:
raise ValidationError(errors)
def get_unique_error_message(self, unique_check):
if len(unique_check) == 1:
return ugettext("Please correct the duplicate data for %(field)s.") % {
"field": unique_check[0],
}
else:
return ugettext("Please correct the duplicate data for %(field)s, "
"which must be unique.") % {
"field": get_text_list(unique_check, six.text_type(_("and"))),
}
def get_date_error_message(self, date_check):
return ugettext("Please correct the duplicate data for %(field_name)s "
"which must be unique for the %(lookup)s in %(date_field)s.") % {
'field_name': date_check[2],
'date_field': date_check[3],
'lookup': six.text_type(date_check[1]),
}
def get_form_error(self):
return ugettext("Please correct the duplicate values below.")
def save_existing_objects(self, commit=True):
self.changed_objects = []
self.deleted_objects = []
if not self.initial_forms:
return []
saved_instances = []
forms_to_delete = self.deleted_forms
for form in self.initial_forms:
obj = form.instance
if form in forms_to_delete:
# If the pk is None, it means that the object can't be
# deleted again. Possible reason for this is that the
# object was already deleted from the DB. Refs #14877.
if obj.pk is None:
continue
self.deleted_objects.append(obj)
if commit:
obj.delete()
elif form.has_changed():
self.changed_objects.append((obj, form.changed_data))
saved_instances.append(self.save_existing(form, obj, commit=commit))
if not commit:
self.saved_forms.append(form)
return saved_instances
def save_new_objects(self, commit=True):
self.new_objects = []
for form in self.extra_forms:
if not form.has_changed():
continue
# If someone has marked an add form for deletion, don't save the
# object.
if self.can_delete and self._should_delete_form(form):
continue
self.new_objects.append(self.save_new(form, commit=commit))
if not commit:
self.saved_forms.append(form)
return self.new_objects
def add_fields(self, form, index):
"""Add a hidden field for the object's primary key."""
from django.db.models import AutoField, OneToOneField, ForeignKey
self._pk_field = pk = self.model._meta.pk
# If a pk isn't editable, then it won't be on the form, so we need to
# add it here so we can tell which object is which when we get the
# data back. Generally, pk.editable should be false, but for some
# reason, auto_created pk fields and AutoField's editable attribute is
# True, so check for that as well.
def pk_is_not_editable(pk):
return ((not pk.editable) or (pk.auto_created or isinstance(pk, AutoField))
or (pk.rel and pk.rel.parent_link and pk_is_not_editable(pk.rel.to._meta.pk)))
if pk_is_not_editable(pk) or pk.name not in form.fields:
if form.is_bound:
# If we're adding the related instance, ignore its primary key
# as it could be an auto-generated default which isn't actually
# in the database.
pk_value = None if form.instance._state.adding else form.instance.pk
else:
try:
if index is not None:
pk_value = self.get_queryset()[index].pk
else:
pk_value = None
except IndexError:
pk_value = None
if isinstance(pk, OneToOneField) or isinstance(pk, ForeignKey):
qs = pk.rel.to._default_manager.get_queryset()
else:
qs = self.model._default_manager.get_queryset()
qs = qs.using(form.instance._state.db)
if form._meta.widgets:
widget = form._meta.widgets.get(self._pk_field.name, HiddenInput)
else:
widget = HiddenInput
form.fields[self._pk_field.name] = ModelChoiceField(qs, initial=pk_value, required=False, widget=widget)
super(BaseModelFormSet, self).add_fields(form, index)
def modelformset_factory(model, form=ModelForm, formfield_callback=None,
formset=BaseModelFormSet, extra=1, can_delete=False,
can_order=False, max_num=None, fields=None, exclude=None,
widgets=None, validate_max=False, localized_fields=None,
labels=None, help_texts=None, error_messages=None,
min_num=None, validate_min=False, field_classes=None):
"""
Returns a FormSet class for the given Django model class.
"""
meta = getattr(form, 'Meta', None)
if meta is None:
meta = type(str('Meta'), (object,), {})
if (getattr(meta, 'fields', fields) is None and
getattr(meta, 'exclude', exclude) is None):
raise ImproperlyConfigured(
"Calling modelformset_factory without defining 'fields' or "
"'exclude' explicitly is prohibited."
)
form = modelform_factory(model, form=form, fields=fields, exclude=exclude,
formfield_callback=formfield_callback,
widgets=widgets, localized_fields=localized_fields,
labels=labels, help_texts=help_texts,
error_messages=error_messages, field_classes=field_classes)
FormSet = formset_factory(form, formset, extra=extra, min_num=min_num, max_num=max_num,
can_order=can_order, can_delete=can_delete,
validate_min=validate_min, validate_max=validate_max)
FormSet.model = model
return FormSet
# InlineFormSets #############################################################
class BaseInlineFormSet(BaseModelFormSet):
"""A formset for child objects related to a parent."""
def __init__(self, data=None, files=None, instance=None,
save_as_new=False, prefix=None, queryset=None, **kwargs):
if instance is None:
self.instance = self.fk.rel.to()
else:
self.instance = instance
self.save_as_new = save_as_new
if queryset is None:
queryset = self.model._default_manager
if self.instance.pk is not None:
qs = queryset.filter(**{self.fk.name: self.instance})
else:
qs = queryset.none()
super(BaseInlineFormSet, self).__init__(data, files, prefix=prefix,
queryset=qs, **kwargs)
def initial_form_count(self):
if self.save_as_new:
return 0
return super(BaseInlineFormSet, self).initial_form_count()
def _construct_form(self, i, **kwargs):
form = super(BaseInlineFormSet, self)._construct_form(i, **kwargs)
if self.save_as_new:
# Remove the primary key from the form's data, we are only
# creating new instances
form.data[form.add_prefix(self._pk_field.name)] = None
# Remove the foreign key from the form's data
form.data[form.add_prefix(self.fk.name)] = None
# Set the fk value here so that the form can do its validation.
fk_value = self.instance.pk
if self.fk.rel.field_name != self.fk.rel.to._meta.pk.name:
fk_value = getattr(self.instance, self.fk.rel.field_name)
fk_value = getattr(fk_value, 'pk', fk_value)
setattr(form.instance, self.fk.get_attname(), fk_value)
return form
@classmethod
def get_default_prefix(cls):
return cls.fk.rel.get_accessor_name(model=cls.model).replace('+', '')
def save_new(self, form, commit=True):
# Ensure the latest copy of the related instance is present on each
# form (it may have been saved after the formset was originally
# instantiated).
setattr(form.instance, self.fk.name, self.instance)
# Use commit=False so we can assign the parent key afterwards, then
# save the object.
obj = form.save(commit=False)
pk_value = getattr(self.instance, self.fk.rel.field_name)
setattr(obj, self.fk.get_attname(), getattr(pk_value, 'pk', pk_value))
if commit:
obj.save()
# form.save_m2m() can be called via the formset later on if commit=False
if commit and hasattr(form, 'save_m2m'):
form.save_m2m()
return obj
def add_fields(self, form, index):
super(BaseInlineFormSet, self).add_fields(form, index)
if self._pk_field == self.fk:
name = self._pk_field.name
kwargs = {'pk_field': True}
else:
# The foreign key field might not be on the form, so we poke at the
# Model field to get the label, since we need that for error messages.
name = self.fk.name
kwargs = {
'label': getattr(form.fields.get(name), 'label', capfirst(self.fk.verbose_name))
}
if self.fk.rel.field_name != self.fk.rel.to._meta.pk.name:
kwargs['to_field'] = self.fk.rel.field_name
# If we're adding a new object, ignore a parent's auto-generated pk
# as it will be regenerated on the save request.
if self.instance._state.adding and form._meta.model._meta.pk.has_default():
self.instance.pk = None
form.fields[name] = InlineForeignKeyField(self.instance, **kwargs)
# Add the generated field to form._meta.fields if it's defined to make
# sure validation isn't skipped on that field.
if form._meta.fields:
if isinstance(form._meta.fields, tuple):
form._meta.fields = list(form._meta.fields)
form._meta.fields.append(self.fk.name)
def get_unique_error_message(self, unique_check):
unique_check = [field for field in unique_check if field != self.fk.name]
return super(BaseInlineFormSet, self).get_unique_error_message(unique_check)
def _get_foreign_key(parent_model, model, fk_name=None, can_fail=False):
"""
Finds and returns the ForeignKey from model to parent if there is one
(returns None if can_fail is True and no such field exists). If fk_name is
provided, assume it is the name of the ForeignKey field. Unless can_fail is
True, an exception is raised if there is no ForeignKey from model to
parent_model.
"""
# avoid circular import
from django.db.models import ForeignKey
opts = model._meta
if fk_name:
fks_to_parent = [f for f in opts.fields if f.name == fk_name]
if len(fks_to_parent) == 1:
fk = fks_to_parent[0]
if not isinstance(fk, ForeignKey) or \
(fk.rel.to != parent_model and
fk.rel.to not in parent_model._meta.get_parent_list()):
raise ValueError(
"fk_name '%s' is not a ForeignKey to '%s.%s'."
% (fk_name, parent_model._meta.app_label, parent_model._meta.object_name))
elif len(fks_to_parent) == 0:
raise ValueError(
"'%s.%s' has no field named '%s'."
% (model._meta.app_label, model._meta.object_name, fk_name))
else:
# Try to discover what the ForeignKey from model to parent_model is
fks_to_parent = [
f for f in opts.fields
if isinstance(f, ForeignKey)
and (f.rel.to == parent_model
or f.rel.to in parent_model._meta.get_parent_list())
]
if len(fks_to_parent) == 1:
fk = fks_to_parent[0]
elif len(fks_to_parent) == 0:
if can_fail:
return
raise ValueError(
"'%s.%s' has no ForeignKey to '%s.%s'." % (
model._meta.app_label,
model._meta.object_name,
parent_model._meta.app_label,
parent_model._meta.object_name,
)
)
else:
raise ValueError(
"'%s.%s' has more than one ForeignKey to '%s.%s'." % (
model._meta.app_label,
model._meta.object_name,
parent_model._meta.app_label,
parent_model._meta.object_name,
)
)
return fk
def inlineformset_factory(parent_model, model, form=ModelForm,
formset=BaseInlineFormSet, fk_name=None,
fields=None, exclude=None, extra=3, can_order=False,
can_delete=True, max_num=None, formfield_callback=None,
widgets=None, validate_max=False, localized_fields=None,
labels=None, help_texts=None, error_messages=None,
min_num=None, validate_min=False, field_classes=None):
"""
Returns an ``InlineFormSet`` for the given kwargs.
You must provide ``fk_name`` if ``model`` has more than one ``ForeignKey``
to ``parent_model``.
"""
fk = _get_foreign_key(parent_model, model, fk_name=fk_name)
# enforce a max_num=1 when the foreign key to the parent model is unique.
if fk.unique:
max_num = 1
kwargs = {
'form': form,
'formfield_callback': formfield_callback,
'formset': formset,
'extra': extra,
'can_delete': can_delete,
'can_order': can_order,
'fields': fields,
'exclude': exclude,
'min_num': min_num,
'max_num': max_num,
'widgets': widgets,
'validate_min': validate_min,
'validate_max': validate_max,
'localized_fields': localized_fields,
'labels': labels,
'help_texts': help_texts,
'error_messages': error_messages,
'field_classes': field_classes,
}
FormSet = modelformset_factory(model, **kwargs)
FormSet.fk = fk
return FormSet
# Fields #####################################################################
class InlineForeignKeyField(Field):
"""
A basic integer field that deals with validating the given value to a
given parent instance in an inline.
"""
widget = HiddenInput
default_error_messages = {
'invalid_choice': _('The inline foreign key did not match the parent instance primary key.'),
}
def __init__(self, parent_instance, *args, **kwargs):
self.parent_instance = parent_instance
self.pk_field = kwargs.pop("pk_field", False)
self.to_field = kwargs.pop("to_field", None)
if self.parent_instance is not None:
if self.to_field:
kwargs["initial"] = getattr(self.parent_instance, self.to_field)
else:
kwargs["initial"] = self.parent_instance.pk
kwargs["required"] = False
super(InlineForeignKeyField, self).__init__(*args, **kwargs)
def clean(self, value):
if value in self.empty_values:
if self.pk_field:
return None
# if there is no value act as we did before.
return self.parent_instance
# ensure the we compare the values as equal types.
if self.to_field:
orig = getattr(self.parent_instance, self.to_field)
else:
orig = self.parent_instance.pk
if force_text(value) != force_text(orig):
raise ValidationError(self.error_messages['invalid_choice'], code='invalid_choice')
return self.parent_instance
def has_changed(self, initial, data):
return False
class ModelChoiceIterator(object):
def __init__(self, field):
self.field = field
self.queryset = field.queryset
def __iter__(self):
if self.field.empty_label is not None:
yield ("", self.field.empty_label)
for obj in self.queryset.iterator():
yield self.choice(obj)
def __len__(self):
return (len(self.queryset) +
(1 if self.field.empty_label is not None else 0))
def choice(self, obj):
return (self.field.prepare_value(obj), self.field.label_from_instance(obj))
class ModelChoiceField(ChoiceField):
"""A ChoiceField whose choices are a model QuerySet."""
# This class is a subclass of ChoiceField for purity, but it doesn't
# actually use any of ChoiceField's implementation.
default_error_messages = {
'invalid_choice': _('Select a valid choice. That choice is not one of'
' the available choices.'),
}
def __init__(self, queryset, empty_label="---------",
required=True, widget=None, label=None, initial=None,
help_text='', to_field_name=None, limit_choices_to=None,
*args, **kwargs):
if required and (initial is not None):
self.empty_label = None
else:
self.empty_label = empty_label
# Call Field instead of ChoiceField __init__() because we don't need
# ChoiceField.__init__().
Field.__init__(self, required, widget, label, initial, help_text,
*args, **kwargs)
self.queryset = queryset
self.limit_choices_to = limit_choices_to # limit the queryset later.
self.to_field_name = to_field_name
def get_limit_choices_to(self):
"""
Returns ``limit_choices_to`` for this form field.
If it is a callable, it will be invoked and the result will be
returned.
"""
if callable(self.limit_choices_to):
return self.limit_choices_to()
return self.limit_choices_to
def __deepcopy__(self, memo):
result = super(ChoiceField, self).__deepcopy__(memo)
# Need to force a new ModelChoiceIterator to be created, bug #11183
result.queryset = result.queryset
return result
def _get_queryset(self):
return self._queryset
def _set_queryset(self, queryset):
self._queryset = queryset
self.widget.choices = self.choices
queryset = property(_get_queryset, _set_queryset)
# this method will be used to create object labels by the QuerySetIterator.
# Override it to customize the label.
def label_from_instance(self, obj):
"""
This method is used to convert objects into strings; it's used to
generate the labels for the choices presented by this object. Subclasses
can override this method to customize the display of the choices.
"""
return smart_text(obj)
def _get_choices(self):
# If self._choices is set, then somebody must have manually set
# the property self.choices. In this case, just return self._choices.
if hasattr(self, '_choices'):
return self._choices
# Otherwise, execute the QuerySet in self.queryset to determine the
# choices dynamically. Return a fresh ModelChoiceIterator that has not been
# consumed. Note that we're instantiating a new ModelChoiceIterator *each*
# time _get_choices() is called (and, thus, each time self.choices is
# accessed) so that we can ensure the QuerySet has not been consumed. This
# construct might look complicated but it allows for lazy evaluation of
# the queryset.
return ModelChoiceIterator(self)
choices = property(_get_choices, ChoiceField._set_choices)
def prepare_value(self, value):
if hasattr(value, '_meta'):
if self.to_field_name:
return value.serializable_value(self.to_field_name)
else:
return value.pk
return super(ModelChoiceField, self).prepare_value(value)
def to_python(self, value):
if value in self.empty_values:
return None
try:
key = self.to_field_name or 'pk'
value = self.queryset.get(**{key: value})
except (ValueError, TypeError, self.queryset.model.DoesNotExist):
raise ValidationError(self.error_messages['invalid_choice'], code='invalid_choice')
return value
def validate(self, value):
return Field.validate(self, value)
def has_changed(self, initial, data):
initial_value = initial if initial is not None else ''
data_value = data if data is not None else ''
return force_text(self.prepare_value(initial_value)) != force_text(data_value)
class ModelMultipleChoiceField(ModelChoiceField):
"""A MultipleChoiceField whose choices are a model QuerySet."""
widget = SelectMultiple
hidden_widget = MultipleHiddenInput
default_error_messages = {
'list': _('Enter a list of values.'),
'invalid_choice': _('Select a valid choice. %(value)s is not one of the'
' available choices.'),
'invalid_pk_value': _('"%(pk)s" is not a valid value for a primary key.')
}
def __init__(self, queryset, required=True, widget=None, label=None,
initial=None, help_text='', *args, **kwargs):
super(ModelMultipleChoiceField, self).__init__(queryset, None,
required, widget, label, initial, help_text, *args, **kwargs)
def to_python(self, value):
if not value:
return []
return list(self._check_values(value))
def clean(self, value):
if self.required and not value:
raise ValidationError(self.error_messages['required'], code='required')
elif not self.required and not value:
return self.queryset.none()
if not isinstance(value, (list, tuple)):
raise ValidationError(self.error_messages['list'], code='list')
qs = self._check_values(value)
# Since this overrides the inherited ModelChoiceField.clean
# we run custom validators here
self.run_validators(value)
return qs
def _check_values(self, value):
"""
Given a list of possible PK values, returns a QuerySet of the
corresponding objects. Raises a ValidationError if a given value is
invalid (not a valid PK, not in the queryset, etc.)
"""
key = self.to_field_name or 'pk'
# deduplicate given values to avoid creating many querysets or
# requiring the database backend deduplicate efficiently.
try:
value = frozenset(value)
except TypeError:
# list of lists isn't hashable, for example
raise ValidationError(
self.error_messages['list'],
code='list',
)
for pk in value:
try:
self.queryset.filter(**{key: pk})
except (ValueError, TypeError):
raise ValidationError(
self.error_messages['invalid_pk_value'],
code='invalid_pk_value',
params={'pk': pk},
)
qs = self.queryset.filter(**{'%s__in' % key: value})
pks = set(force_text(getattr(o, key)) for o in qs)
for val in value:
if force_text(val) not in pks:
raise ValidationError(
self.error_messages['invalid_choice'],
code='invalid_choice',
params={'value': val},
)
return qs
def prepare_value(self, value):
if (hasattr(value, '__iter__') and
not isinstance(value, six.text_type) and
not hasattr(value, '_meta')):
return [super(ModelMultipleChoiceField, self).prepare_value(v) for v in value]
return super(ModelMultipleChoiceField, self).prepare_value(value)
def has_changed(self, initial, data):
if initial is None:
initial = []
if data is None:
data = []
if len(initial) != len(data):
return True
initial_set = set(force_text(value) for value in self.prepare_value(initial))
data_set = set(force_text(value) for value in data)
return data_set != initial_set
def modelform_defines_fields(form_class):
return (form_class is not None and (
hasattr(form_class, '_meta') and
(form_class._meta.fields is not None or
form_class._meta.exclude is not None)
))
Jump to Line
Something went wrong with that request. Please try again.