Source code
import copy
import json
from django import forms
from django.conf import settings
from django.core.exceptions import ValidationError
from django.core.validators import URLValidator
from django.db.models import CASCADE, UUIDField
from django.forms.widgets import Select
from django.urls import reverse
from django.urls.exceptions import NoReverseMatch
from django.utils.html import smart_urlquote
from django.utils.http import urlencode
from django.utils.text import Truncator
from django.utils.translation import get_language
from django.utils.translation import gettext as _
class RelatedFieldWidgetWrapper(forms.Widget):
"""
This class is a wrapper to a given widget to add the add icon for the
admin interface.
"""
template_name = "admin/widgets/related_widget_wrapper.html"
def __init__(
self,
widget,
rel,
admin_site,
can_add_related=None,
can_change_related=False,
can_delete_related=False,
can_view_related=False,
):
self.needs_multipart_form = widget.needs_multipart_form
self.attrs = widget.attrs
self.widget = widget
self.rel = rel
# Backwards compatible check for whether a user can add related
# objects.
if can_add_related is None:
can_add_related = admin_site.is_registered(rel.model)
self.can_add_related = can_add_related
if not isinstance(widget, AutocompleteMixin):
self.attrs["data-context"] = "available-source"
# Only single-select Select widgets are supported.
supported = not getattr(
widget, "allow_multiple_selected", False
) and isinstance(widget, Select)
self.can_change_related = supported and can_change_related
# XXX: The deletion UX can be confusing when dealing with cascading
# deletion.
cascade = getattr(rel, "on_delete", None) is CASCADE
self.can_delete_related = supported and not cascade and can_delete_related
self.can_view_related = supported and can_view_related
# To check if the related object is registered with this AdminSite.
self.admin_site = admin_site
self.use_fieldset = widget.use_fieldset
def __deepcopy__(self, memo):
obj = copy.copy(self)
obj.widget = copy.deepcopy(self.widget, memo)
obj.attrs = self.widget.attrs
memo[id(self)] = obj
return obj
@property
def is_hidden(self):
return self.widget.is_hidden
@property
def media(self):
return self.widget.media
@property
def choices(self):
return self.widget.choices
@choices.setter
def choices(self, value):
self.widget.choices = value
def get_related_url(self, info, action, *args):
return reverse(
"admin:%s_%s_%s" % (*info, action),
current_app=self.admin_site.name,
args=args,
)
def get_context(self, name, value, attrs):
from django.contrib.admin.views.main import (
IS_POPUP_VAR,
SOURCE_MODEL_VAR,
TO_FIELD_VAR,
)
rel_opts = self.rel.model._meta
info = (rel_opts.app_label, rel_opts.model_name)
related_field_name = self.rel.get_related_field().name
app_label = self.rel.field.model._meta.app_label
model_name = self.rel.field.model._meta.model_name
url_params = "&".join(
"%s=%s" % param
for param in [
(TO_FIELD_VAR, related_field_name),
(IS_POPUP_VAR, 1),
(SOURCE_MODEL_VAR, f"{app_label}.{model_name}"),
]
)
context = {
"rendered_widget": self.widget.render(name, value, attrs),
"is_hidden": self.is_hidden,
"name": name,
"url_params": url_params,
"model": rel_opts.verbose_name,
"model_name": rel_opts.model_name,
"can_add_related": self.can_add_related,
"can_change_related": self.can_change_related,
"can_delete_related": self.can_delete_related,
"can_view_related": self.can_view_related,
"model_has_limit_choices_to": self.rel.limit_choices_to,
}
if self.can_add_related:
context["add_related_url"] = self.get_related_url(info, "add")
if self.can_delete_related:
context["delete_related_template_url"] = self.get_related_url(
info, "delete", "__fk__"
)
if self.can_view_related or self.can_change_related:
context["view_related_url_params"] = f"{TO_FIELD_VAR}={related_field_name}"
context["change_related_template_url"] = self.get_related_url(
info, "change", "__fk__"
)
return context
def value_from_datadict(self, data, files, name):
return self.widget.value_from_datadict(data, files, name)
def value_omitted_from_data(self, data, files, name):
return self.widget.value_omitted_from_data(data, files, name)
def id_for_label(self, id_):
return self.widget.id_for_label(id_)