• Language: en

Source code for django.forms.models

"""
Helper functions for creating Form classes from Django models
and database field objects.
"""

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.encoding import force_text
from django.utils.text import capfirst, get_text_list
from django.utils.translation import gettext, gettext_lazy as _

__all__ = (
    'ModelForm', 'BaseModelForm', 'model_to_dict', 'fields_for_model',
    'ModelChoiceField', 'ModelMultipleChoiceField', 'ALL_FIELDS',
    'BaseModelFormSet', 'modelformset_factory', 'BaseInlineFormSet',
    'inlineformset_factory', 'modelform_factory',
)

ALL_FIELDS = '__all__'


def construct_instance(form, instance, fields=None, exclude=None):
    """
    Construct and return a model instance from the bound ``form``'s
    ``cleaned_data``, but do 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
        # Leave defaults for fields that aren't in POST data, except for
        # checkbox inputs because they don't appear in POST data if not checked.
        if (f.has_default() and
                form[f.name].field.widget.value_omitted_from_data(form.data, form.files, form.add_prefix(f.name))):
            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


# ModelForms #################################################################

def model_to_dict(instance, fields=None, exclude=None):
    """
    Return 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, return only the
    named.

    ``exclude`` is an optional list of field names. If provided, exclude the
    named from the returned dict, even if they are listed in the ``fields``
    argument.
    """
    opts = instance._meta
    data = {}
    for f in chain(opts.concrete_fields, opts.private_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
        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):
    """
    Return an ``OrderedDict`` containing form fields for the given model.

    ``fields`` is an optional list of field names. If provided, return only the
    named fields.

    ``exclude`` is an optional list of field names. If provided, exclude the
    named fields 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_private_fields = [f for f in opts.private_fields if isinstance(f, ModelField)]
    for f in sorted(chain(opts.concrete_fields, sortable_private_fields, opts.many_to_many)):
        if not getattr(f, 'editable', False):
            if (fields is not None and f.name in fields and
                    (exclude is None or f.name not in exclude)):
                raise FieldError(
                    "'%s' cannot be specified for %s model form as it is a non-editable field" % (
                        f.name, model.__name__)
                )
            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:
            # Apply ``limit_choices_to``.
            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)
            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:
    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):
        base_formfield_callback = None
        for b in bases:
            if hasattr(b, 'Meta') and hasattr(b.Meta, 'formfield_callback'):
                base_formfield_callback = b.Meta.formfield_callback
                break

        formfield_callback = attrs.pop('formfield_callback', base_formfield_callback)

        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, str) 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 fields.items() 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, use_required_attribute=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().__init__(
            data, files, auto_id, prefix, object_data, error_class,
            label_suffix, empty_permitted, use_required_attribute=use_required_attribute,
        )

    def _get_validation_exclusions(self):
        """
        For backwards-compatibility, exclude several types of fields from model
        validation. See tickets #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)
                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

        # Allow the model generated by construct_instance() to raise
        # ValidationError and have them handled in the same way as others.
        if hasattr(errors, 'error_dict'):
            error_dict = errors.error_dict
        else:
            error_dict = {NON_FIELD_ERRORS: errors}

        for field, messages in 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()

        # 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):
                exclude.append(name)

        try:
            self.instance = construct_instance(self, self.instance, opts.fields, opts.exclude)
        except ValidationError as e:
            self._update_errors(e)

        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):
        """
        Call the instance's validate_unique() method and update 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_m2m(self):
        """
        Save the many-to-many fields and generic relations for this form.
        """
        cleaned_data = self.cleaned_data
        exclude = self._meta.exclude
        fields = self._meta.fields
        opts = self.instance._meta
        # Note that for historical reasons we want to include also
        # private_fields here. (GenericRelation was previously a fake
        # m2m field).
        for f in chain(opts.many_to_many, opts.private_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(self.instance, cleaned_data[f.name])

    def save(self, commit=True):
        """
        Save this form's self.instance object if commit=True. Otherwise, add
        a save_m2m() method to the form which can be called after the instance
        is saved manually at a later time. Return the model instance.
        """
        if self.errors:
            raise ValueError(
                "The %s could not be %s because the data didn't validate." % (
                    self.instance._meta.object_name,
                    'created' if self.instance._state.adding else 'changed',
                )
            )
        if commit:
            # If committing, save the instance and the m2m data immediately.
            self.instance.save()
            self._save_m2m()
        else:
            # If not committing, add a method to the form to allow deferred
            # saving of m2m data.
            self.save_m2m = self._save_m2m
        return self.instance

    save.alters_data = True


[docs]class ModelForm(BaseModelForm, metaclass=ModelFormMetaclass): pass
[docs]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): """ Return a ModelForm containing form fields for the given model. ``fields`` is an optional list of field names. If provided, include only the named fields in the returned fields. If omitted or '__all__', use all fields. ``exclude`` is an optional list of field names. If provided, exclude the named fields 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. bases = (form.Meta,) if hasattr(form, 'Meta') else () Meta = type('Meta', bases, attrs) if formfield_callback: Meta.formfield_callback = staticmethod(formfield_callback) # 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 } 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 # Set of fields that must be unique among forms of this set. unique_fields = set() def __init__(self, data=None, files=None, auto_id='id_%s', prefix=None, queryset=None, *, initial=None, **kwargs): self.queryset = queryset self.initial_extra = initial defaults = {'data': data, 'files': files, 'auto_id': auto_id, 'prefix': prefix} defaults.update(kwargs) super().__init__(**defaults) def initial_form_count(self): """Return the number of forms that are required in this FormSet.""" if not (self.data or self.files): return len(self.get_queryset()) return super().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.remote_field is not None: field = field.remote_field.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()._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): """Save and return a new model instance for the given form.""" return form.save(commit=commit) def save_existing(self, form, instance, commit=True): """Save and return an existing model instance for the given form.""" return form.save(commit=commit) def delete_existing(self, obj, commit=True): """Deletes an existing model instance.""" if commit: obj.delete() def save(self, commit=True): """ Save model instances for every form, adding and changing instances as necessary, and return 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 the data for the set of fields that must be unique among the forms. row_data = ( field if field in self.unique_fields else 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 gettext("Please correct the duplicate data for %(field)s.") % { "field": unique_check[0], } else: return gettext("Please correct the duplicate data for %(field)s, which must be unique.") % { "field": get_text_list(unique_check, _("and")), } def get_date_error_message(self, date_check): return gettext( "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': str(date_check[1]), } def get_form_error(self): return gettext("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 the pk is None, it means either: # 1. The object is an unexpected empty model, created by invalid # POST data such as an object outside the formset's queryset. # 2. The object was already deleted from the database. if obj.pk is None: continue if form in forms_to_delete: self.deleted_objects.append(obj) self.delete_existing(obj, commit=commit) 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.remote_field and pk.remote_field.parent_link and pk_is_not_editable(pk.remote_field.model._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.remote_field.model._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().add_fields(form, index)
[docs]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): """Return a FormSet class for the given Django model class.""" meta = getattr(form, 'Meta', None) 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.remote_field.model() 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() self.unique_fields = {self.fk.name} super().__init__(data, files, prefix=prefix, queryset=qs, **kwargs) # Add the generated field to form._meta.fields if it's defined to make # sure validation isn't skipped on that field. if self.form._meta.fields and self.fk.name not in self.form._meta.fields: if isinstance(self.form._meta.fields, tuple): self.form._meta.fields = list(self.form._meta.fields) self.form._meta.fields.append(self.fk.name) def initial_form_count(self): if self.save_as_new: return 0 return super().initial_form_count() def _construct_form(self, i, **kwargs): form = super()._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.remote_field.field_name != self.fk.remote_field.model._meta.pk.name: fk_value = getattr(self.instance, self.fk.remote_field.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.remote_field.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.remote_field.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().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.remote_field.field_name != self.fk.remote_field.model._meta.pk.name: kwargs['to_field'] = self.fk.remote_field.field_name # If we're adding a new object, ignore a parent's auto-generated key # as it will be regenerated on the save request. if self.instance._state.adding: if kwargs.get('to_field') is not None: to_field = self.instance._meta.get_field(kwargs['to_field']) else: to_field = self.instance._meta.pk if to_field.has_default(): setattr(self.instance, to_field.attname, None) form.fields[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().get_unique_error_message(unique_check) def _get_foreign_key(parent_model, model, fk_name=None, can_fail=False): """ Find and return the ForeignKey from model to parent if there is one (return 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, raise an exception if there isn't a 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.remote_field.model != parent_model and fk.remote_field.model not in parent_model._meta.get_parent_list()): raise ValueError( "fk_name '%s' is not a ForeignKey to '%s'." % (fk_name, parent_model._meta.label) ) elif len(fks_to_parent) == 0: raise ValueError( "'%s' has no field named '%s'." % (model._meta.label, 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.remote_field.model == parent_model or f.remote_field.model 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' has no ForeignKey to '%s'." % ( model._meta.label, parent_model._meta.label, ) ) else: raise ValueError( "'%s' has more than one ForeignKey to '%s'." % ( model._meta.label, parent_model._meta.label, ) ) return fk
[docs]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): """ Return an ``InlineFormSet`` for the given kwargs. ``fk_name`` must be provided 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 value did not match the parent instance.'), } def __init__(self, parent_instance, *args, pk_field=False, to_field=None, **kwargs): self.parent_instance = parent_instance self.pk_field = pk_field self.to_field = to_field 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().__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: 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) queryset = self.queryset.all() # Can't use iterator() when queryset uses prefetch_related() if not queryset._prefetch_related_lookups: queryset = queryset.iterator() for obj in queryset: 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))
[docs]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.'), } iterator = ModelChoiceIterator 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): """ Return ``limit_choices_to`` for this form field. If it is a callable, invoke it and return the result. """ 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 if self.queryset is not None: result.queryset = self.queryset.all() 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): """ Convert objects into strings and generate the labels for the choices presented by this object. Subclasses can override this method to customize the display of the choices. """ return force_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 self.iterator(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().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)
[docs]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.') } def __init__(self, queryset, required=True, widget=None, label=None, initial=None, help_text='', *args, **kwargs): super().__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): value = self.prepare_value(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, return a QuerySet of the corresponding objects. Raise 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, str) and not hasattr(value, '_meta')): return [super(ModelMultipleChoiceField, self).prepare_value(v) for v in value] return super().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) ))
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