"""
Helper functions for creating Form classes from Django models
and database field objects.
"""
from django.utils.encoding import smart_unicode, force_unicode
from django.utils.datastructures import SortedDict
from django.utils.text import get_text_list, capfirst
from django.utils.translation import ugettext_lazy as _, ugettext
from util import ValidationError, ErrorList
from forms import BaseForm, get_declared_fields, NON_FIELD_ERRORS
from fields import Field, ChoiceField, IntegerField, EMPTY_VALUES
from widgets import Select, SelectMultiple, HiddenInput, MultipleHiddenInput
from widgets import media_property
from formsets import BaseFormSet, formset_factory, DELETION_FIELD_NAME
try:
set
except NameError:
from sets import Set as set # Python 2.3 fallback
__all__ = (
'ModelForm', 'BaseModelForm', 'model_to_dict', 'fields_for_model',
'save_instance', 'form_for_fields', 'ModelChoiceField',
'ModelMultipleChoiceField',
)
def save_instance(form, instance, fields=None, fail_message='saved',
commit=True, exclude=None):
"""
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``.
"""
from django.db import models
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))
cleaned_data = form.cleaned_data
file_field_list = []
for f in opts.fields:
if not f.editable or isinstance(f, models.AutoField) \
or not f.name in cleaned_data:
continue
if fields and f.name not in fields:
continue
if exclude and f.name in exclude:
continue
# OneToOneField doesn't allow assignment of None. Guard against that
# instead of allowing it and throwing an error.
if isinstance(f, models.OneToOneField) and cleaned_data[f.name] is None:
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])
# Wrap up the saving of m2m data as a function.
def save_m2m():
opts = instance._meta
cleaned_data = form.cleaned_data
for f in opts.many_to_many:
if fields and f.name not in fields:
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
def make_model_save(model, fields, fail_message):
"""Returns the save() method for a Form."""
def save(self, commit=True):
return save_instance(self, model(), fields, fail_message, commit)
return save
def make_instance_save(instance, fields, fail_message):
"""Returns the save() method for a Form."""
def save(self, commit=True):
return save_instance(self, instance, fields, fail_message, commit)
return save
def form_for_fields(field_list):
"""
Returns a Form class for the given list of Django database field instances.
"""
fields = SortedDict([(f.name, f.formfield())
for f in field_list if f.editable])
return type('FormForFields', (BaseForm,), {'base_fields': fields})
# 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, OneToOneField
opts = instance._meta
data = {}
for f in opts.fields + opts.many_to_many:
if not f.editable:
continue
if fields and not f.name in fields:
continue
if exclude and f.name in exclude:
continue
if isinstance(f, ManyToManyField):
# If the object doesn't have a primry 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.
data[f.name] = [obj.pk for obj in f.value_from_object(instance)]
else:
data[f.name] = f.value_from_object(instance)
return data
def fields_for_model(model, fields=None, exclude=None, formfield_callback=lambda f: f.formfield()):
"""
Returns a ``SortedDict`` 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.
"""
field_list = []
opts = model._meta
for f in opts.fields + opts.many_to_many:
if not f.editable:
continue
if fields and not f.name in fields:
continue
if exclude and f.name in exclude:
continue
formfield = formfield_callback(f)
if formfield:
field_list.append((f.name, formfield))
field_dict = SortedDict(field_list)
if fields:
field_dict = SortedDict([(f, field_dict.get(f)) for f in fields if (not exclude) or (exclude and f not in exclude)])
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)
class ModelFormMetaclass(type):
def __new__(cls, name, bases, attrs):
formfield_callback = attrs.pop('formfield_callback',
lambda f: f.formfield())
try:
parents = [b for b in bases if issubclass(b, ModelForm)]
except NameError:
# We are defining ModelForm itself.
parents = None
declared_fields = get_declared_fields(bases, attrs, False)
new_class = super(ModelFormMetaclass, cls).__new__(cls, name, bases,
attrs)
if not parents:
return new_class
if 'media' not in attrs:
new_class.media = media_property(new_class)
opts = new_class._meta = ModelFormOptions(getattr(new_class, 'Meta', None))
if opts.model:
# If a model is defined, extract form fields from it.
fields = fields_for_model(opts.model, opts.fields,
opts.exclude, formfield_callback)
# Override default model fields with any custom declared ones
# (plus, include all the other declared fields).
fields.update(declared_fields)
else:
fields = declared_fields
new_class.declared_fields = 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=':',
empty_permitted=False, instance=None):
opts = self._meta
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)
super(BaseModelForm, self).__init__(data, files, auto_id, prefix, object_data,
error_class, label_suffix, empty_permitted)
def clean(self):
self.validate_unique()
return self.cleaned_data
def validate_unique(self):
unique_checks, date_checks = self._get_unique_checks()
form_errors = []
bad_fields = set()
field_errors, global_errors = self._perform_unique_checks(unique_checks)
bad_fields.union(field_errors)
form_errors.extend(global_errors)
field_errors, global_errors = self._perform_date_checks(date_checks)
bad_fields.union(field_errors)
form_errors.extend(global_errors)
for field_name in bad_fields:
del self.cleaned_data[field_name]
if form_errors:
# Raise the unique together errors since they are considered
# form-wide.
raise ValidationError(form_errors)
def _get_unique_checks(self):
from django.db.models.fields import FieldDoesNotExist, Field as ModelField
# Gather a list of checks to perform. We only perform unique checks
# for fields present and not None in cleaned_data. Since this is a
# ModelForm, some fields may have been excluded; we can't perform a unique
# check on a form that is missing fields involved in that check. It also does
# not make sense to check data that didn't validate, and since NULL does not
# equal NULL in SQL we should not do any unique checking for NULL values.
unique_checks = []
# these are checks for the unique_for_<date/year/month>
date_checks = []
for check in self.instance._meta.unique_together[:]:
fields_on_form = [field for field in check if self.cleaned_data.get(field) is not None]
if len(fields_on_form) == len(check):
unique_checks.append(check)
# Gather a list of checks for fields declared as unique and add them to
# the list of checks. Again, skip empty fields and any that did not validate.
for name in self.fields:
try:
f = self.instance._meta.get_field_by_name(name)[0]
except FieldDoesNotExist:
# This is an extra field that's not on the ModelForm, ignore it
continue
if not isinstance(f, ModelField):
# This is an extra field that happens to have a name that matches,
# for example, a related object accessor for this model. So
# get_field_by_name found it, but it is not a Field so do not proceed
# to use it as if it were.
continue
if self.cleaned_data.get(name) is None:
continue
if f.unique:
unique_checks.append((name,))
if f.unique_for_date and self.cleaned_data.get(f.unique_for_date) is not None:
date_checks.append(('date', name, f.unique_for_date))
if f.unique_for_year and self.cleaned_data.get(f.unique_for_year) is not None:
date_checks.append(('year', name, f.unique_for_year))
if f.unique_for_month and self.cleaned_data.get(f.unique_for_month) is not None:
date_checks.append(('month', name, f.unique_for_month))
return unique_checks, date_checks
def _perform_unique_checks(self, unique_checks):
bad_fields = set()
form_errors = []
for unique_check in unique_checks:
# Try to look up an existing object with the same values as this
# object's values for all the unique field.
lookup_kwargs = {}
for field_name in unique_check:
lookup_value = self.cleaned_data[field_name]
# ModelChoiceField will return an object instance rather than
# a raw primary key value, so convert it to a pk value before
# using it in a lookup.
if isinstance(self.fields[field_name], ModelChoiceField):
lookup_value = lookup_value.pk
lookup_kwargs[str(field_name)] = lookup_value
qs = self.instance.__class__._default_manager.filter(**lookup_kwargs)
# Exclude the current object from the query if we are editing an
# instance (as opposed to creating a new one)
if self.instance.pk is not None:
qs = qs.exclude(pk=self.instance.pk)
# This cute trick with extra/values is the most efficient way to
# tell if a particular query returns any results.
if qs.extra(select={'a': 1}).values('a').order_by():
if len(unique_check) == 1:
self._errors[unique_check[0]] = ErrorList([self.unique_error_message(unique_check)])
else:
form_errors.append(self.unique_error_message(unique_check))
# Mark these fields as needing to be removed from cleaned data
# later.
for field_name in unique_check:
bad_fields.add(field_name)
return bad_fields, form_errors
def _perform_date_checks(self, date_checks):
bad_fields = set()
for lookup_type, field, unique_for in date_checks:
lookup_kwargs = {}
# there's a ticket to add a date lookup, we can remove this special
# case if that makes it's way in
if lookup_type == 'date':
date = self.cleaned_data[unique_for]
lookup_kwargs['%s__day' % unique_for] = date.day
lookup_kwargs['%s__month' % unique_for] = date.month
lookup_kwargs['%s__year' % unique_for] = date.year
else:
lookup_kwargs['%s__%s' % (unique_for, lookup_type)] = getattr(self.cleaned_data[unique_for], lookup_type)
lookup_kwargs[field] = self.cleaned_data[field]
qs = self.instance.__class__._default_manager.filter(**lookup_kwargs)
# Exclude the current object from the query if we are editing an
# instance (as opposed to creating a new one)
if self.instance.pk is not None:
qs = qs.exclude(pk=self.instance.pk)
# This cute trick with extra/values is the most efficient way to
# tell if a particular query returns any results.
if qs.extra(select={'a': 1}).values('a').order_by():
self._errors[field] = ErrorList([
self.date_error_message(lookup_type, field, unique_for)
])
bad_fields.add(field)
return bad_fields, []
def date_error_message(self, lookup_type, field, unique_for):
return _(u"%(field_name)s must be unique for %(date_field)s %(lookup)s.") % {
'field_name': unicode(self.fields[field].label),
'date_field': unicode(self.fields[unique_for].label),
'lookup': lookup_type,
}
def unique_error_message(self, unique_check):
model_name = capfirst(self.instance._meta.verbose_name)
# A unique field
if len(unique_check) == 1:
field_name = unique_check[0]
field_label = self.fields[field_name].label
# Insert the error into the error dict, very sneaky
return _(u"%(model_name)s with this %(field_label)s already exists.") % {
'model_name': unicode(model_name),
'field_label': unicode(field_label)
}
# unique_together
else:
field_labels = [self.fields[field_name].label for field_name in unique_check]
field_labels = get_text_list(field_labels, _('and'))
return _(u"%(model_name)s with this %(field_label)s already exists.") % {
'model_name': unicode(model_name),
'field_label': unicode(field_labels)
}
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, exclude=self._meta.exclude)
save.alters_data = True
class ModelForm(BaseModelForm):
__metaclass__ = ModelFormMetaclass
def modelform_factory(model, form=ModelForm, fields=None, exclude=None,
formfield_callback=lambda f: f.formfield()):
# 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 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('Meta', parent, attrs)
# Give this new form class a reasonable name.
class_name = model.__name__ + 'Form'
# Class attributes for the new form class.
form_class_attrs = {
'Meta': Meta,
'formfield_callback': formfield_callback
}
return ModelFormMetaclass(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
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 = dict([(o.pk, o) for o in self.get_queryset()])
return self._object_dict.get(pk)
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
pk = pk_field.get_db_prep_lookup('exact', pk)
if isinstance(pk, list):
pk = pk[0]
kwargs['instance'] = self._existing_object(pk)
if i < self.initial_form_count() and not kwargs.get('instance'):
kwargs['instance'] = self.get_queryset()[i]
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_query_set()
# 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)
if self.max_num > 0:
self._queryset = qs[:self.max_num]
else:
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)
def clean(self):
self.validate_unique()
def validate_unique(self):
# Iterate over the forms so that we can find one with potentially valid
# data from which to extract the error checks
for form in self.forms:
if hasattr(form, 'cleaned_data'):
break
else:
return
unique_checks, date_checks = form._get_unique_checks()
errors = []
# Do each of the unique checks (unique and unique_together)
for unique_check in unique_checks:
seen_data = set()
for form in self.forms:
# if the form doesn't have cleaned_data then we ignore it,
# it's already invalid
if not hasattr(form, "cleaned_data"):
continue
# get each of the fields for which we have data on this form
if [f for f in unique_check if f in form.cleaned_data and form.cleaned_data[f] is not None]:
# get the data itself
row_data = tuple([form.cleaned_data[field] for field in unique_check])
# if we've aready 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.get_form_error()
del form.cleaned_data
break
# mark the data as seen
seen_data.add(row_data)
# iterate over each of the date checks now
for date_check in date_checks:
seen_data = set()
lookup, field, unique_for = date_check
for form in self.forms:
# if the form doesn't have cleaned_data then we ignore it,
# it's already invalid
if not hasattr(self, 'cleaned_data'):
continue
# 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 aready 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.get_form_error()
del form.cleaned_data
break
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, unicode(_("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[1],
'date_field': date_check[2],
'lookup': unicode(date_check[0]),
}
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.get_queryset():
return []
saved_instances = []
for form in self.initial_forms:
pk_name = self._pk_field.name
raw_pk_value = form._raw_value(pk_name)
# clean() for different types of PK fields can sometimes return
# the model instance, and sometimes the PK. Handle either.
pk_value = form.fields[pk_name].clean(raw_pk_value)
pk_value = getattr(pk_value, 'pk', pk_value)
obj = self._existing_object(pk_value)
if self.can_delete:
raw_delete_value = form._raw_value(DELETION_FIELD_NAME)
should_delete = form.fields[DELETION_FIELD_NAME].clean(raw_delete_value)
if should_delete:
self.deleted_objects.append(obj)
obj.delete()
continue
if 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:
raw_delete_value = form._raw_value(DELETION_FIELD_NAME)
should_delete = form.fields[DELETION_FIELD_NAME].clean(raw_delete_value)
if should_delete:
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:
pk_value = form.instance.pk
else:
try:
pk_value = self.get_queryset()[index].pk
except IndexError:
pk_value = None
if isinstance(pk, OneToOneField) or isinstance(pk, ForeignKey):
qs = pk.rel.to._default_manager.get_query_set()
else:
qs = self.model._default_manager.get_query_set()
form.fields[self._pk_field.name] = ModelChoiceField(qs, initial=pk_value, required=False, widget=HiddenInput)
super(BaseModelFormSet, self).add_fields(form, index)
def modelformset_factory(model, form=ModelForm, formfield_callback=lambda f: f.formfield(),
formset=BaseModelFormSet,
extra=1, can_delete=False, can_order=False,
max_num=0, fields=None, exclude=None):
"""
Returns a FormSet class for the given Django model class.
"""
form = modelform_factory(model, form=form, fields=fields, exclude=exclude,
formfield_callback=formfield_callback)
FormSet = formset_factory(form, formset, extra=extra, max_num=max_num,
can_order=can_order, can_delete=can_delete)
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):
from django.db.models.fields.related import RelatedObject
if instance is None:
self.instance = self.model()
else:
self.instance = instance
self.save_as_new = save_as_new
# is there a better way to get the object descriptor?
self.rel_name = RelatedObject(self.fk.rel.to, self.model, self.fk).get_accessor_name()
if self.fk.rel.field_name == self.fk.rel.to._meta.pk.name:
backlink_value = self.instance
else:
backlink_value = getattr(self.instance, self.fk.rel.field_name)
qs = self.model._default_manager.filter(**{self.fk.name: backlink_value})
super(BaseInlineFormSet, self).__init__(data, files, prefix=prefix,
queryset=qs)
def initial_form_count(self):
if self.save_as_new:
return 0
return super(BaseInlineFormSet, self).initial_form_count()
def total_form_count(self):
if self.save_as_new:
return super(BaseInlineFormSet, self).initial_form_count()
return super(BaseInlineFormSet, self).total_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
return form
#@classmethod
def get_default_prefix(cls):
from django.db.models.fields.related import RelatedObject
return RelatedObject(cls.fk.rel.to, cls.model, cls.fk).get_accessor_name()
get_default_prefix = classmethod(get_default_prefix)
def save_new(self, form, commit=True):
# 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:
form.fields[self._pk_field.name] = InlineForeignKeyField(self.instance, 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.
kwargs = {
'label': getattr(form.fields.get(self.fk.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
form.fields[self.fk.name] = InlineForeignKeyField(self.instance, **kwargs)
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. Unles 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 Exception("fk_name '%s' is not a ForeignKey to %s" % (fk_name, parent_model))
elif len(fks_to_parent) == 0:
raise Exception("%s has no field named '%s'" % (model, 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 Exception("%s has no ForeignKey to %s" % (model, parent_model))
else:
raise Exception("%s has more than 1 ForeignKey to %s" % (model, parent_model))
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=0,
formfield_callback=lambda f: f.formfield()):
"""
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,
'max_num': max_num,
}
FormSet = modelformset_factory(model, **kwargs)
FormSet.fk = fk
return FormSet
# Fields #####################################################################
class InlineForeignKeyHiddenInput(HiddenInput):
def _has_changed(self, initial, data):
return False
class InlineForeignKeyField(Field):
"""
A basic integer field that deals with validating the given value to a
given parent instance in an inline.
"""
default_error_messages = {
'invalid_choice': _(u'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
kwargs["widget"] = InlineForeignKeyHiddenInput
super(InlineForeignKeyField, self).__init__(*args, **kwargs)
def clean(self, value):
if value in 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_unicode(value) != force_unicode(orig):
raise ValidationError(self.error_messages['invalid_choice'])
return self.parent_instance
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 (u"", self.field.empty_label)
if self.field.cache_choices:
if self.field.choice_cache is None:
self.field.choice_cache = [
self.choice(obj) for obj in self.queryset.all()
]
for choice in self.field.choice_cache:
yield choice
else:
for obj in self.queryset.all():
yield self.choice(obj)
def choice(self, obj):
if self.field.to_field_name:
key = obj.serializable_value(self.field.to_field_name)
else:
key = obj.pk
return (key, 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': _(u'Select a valid choice. That choice is not one of'
u' the available choices.'),
}
def __init__(self, queryset, empty_label=u"---------", cache_choices=False,
required=True, widget=None, label=None, initial=None,
help_text=None, to_field_name=None, *args, **kwargs):
if required and (initial is not None):
self.empty_label = None
else:
self.empty_label = empty_label
self.cache_choices = cache_choices
# 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.choice_cache = None
self.to_field_name = to_field_name
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_unicode(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 QuerySetIterator that has not been
# consumed. Note that we're instantiating a new QuerySetIterator *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 clean(self, value):
Field.clean(self, value)
if value in EMPTY_VALUES:
return None
try:
key = self.to_field_name or 'pk'
value = self.queryset.get(**{key: value})
except self.queryset.model.DoesNotExist:
raise ValidationError(self.error_messages['invalid_choice'])
return value
class ModelMultipleChoiceField(ModelChoiceField):
"""A MultipleChoiceField whose choices are a model QuerySet."""
widget = SelectMultiple
hidden_widget = MultipleHiddenInput
default_error_messages = {
'list': _(u'Enter a list of values.'),
'invalid_choice': _(u'Select a valid choice. %s is not one of the'
u' available choices.'),
'invalid_pk_value': _(u'"%s" is not a valid value for a primary key.')
}
def __init__(self, queryset, cache_choices=False, required=True,
widget=None, label=None, initial=None,
help_text=None, *args, **kwargs):
super(ModelMultipleChoiceField, self).__init__(queryset, None,
cache_choices, required, widget, label, initial, help_text,
*args, **kwargs)
def clean(self, value):
if self.required and not value:
raise ValidationError(self.error_messages['required'])
elif not self.required and not value:
return []
if not isinstance(value, (list, tuple)):
raise ValidationError(self.error_messages['list'])
for pk in value:
try:
self.queryset.filter(pk=pk)
except ValueError:
raise ValidationError(self.error_messages['invalid_pk_value'] % pk)
qs = self.queryset.filter(pk__in=value)
pks = set([force_unicode(o.pk) for o in qs])
for val in value:
if force_unicode(val) not in pks:
raise ValidationError(self.error_messages['invalid_choice'] % val)
return qs