Fixed #31262 -- Added support for mappings on model fields and ChoiceField's choices.

django/forms/fields.py

@@ -17,7 +17,6 @@ from urllib.parse import urlsplit, urlunsplit
 
 from django.core import validators
 from django.core.exceptions import ValidationError
-from django.db.models.enums import ChoicesMeta
 from django.forms.boundfield import BoundField
 from django.forms.utils import from_current_timezone, to_current_timezone
 from django.forms.widgets import (
@@ -42,6 +41,7 @@ from django.forms.widgets import (
     URLInput,
 )
 from django.utils import formats
+from django.utils.choices import normalize_choices
 from django.utils.dateparse import parse_datetime, parse_duration
 from django.utils.deprecation import RemovedInDjango60Warning
 from django.utils.duration import duration_string
@@ -861,14 +861,6 @@ class NullBooleanField(BooleanField):
         pass
 
 
-class CallableChoiceIterator:
-    def __init__(self, choices_func):
-        self.choices_func = choices_func
-
-    def __iter__(self):
-        yield from self.choices_func()
-
-
 class ChoiceField(Field):
     widget = Select
     default_error_messages = {
@@ -879,8 +871,6 @@ class ChoiceField(Field):
 
     def __init__(self, *, choices=(), **kwargs):
         super().__init__(**kwargs)
-        if isinstance(choices, ChoicesMeta):
-            choices = choices.choices
         self.choices = choices
 
     def __deepcopy__(self, memo):
@@ -888,21 +878,15 @@ class ChoiceField(Field):
         result._choices = copy.deepcopy(self._choices, memo)
         return result
 
-    def _get_choices(self):
+    @property
+    def choices(self):
         return self._choices
 
-    def _set_choices(self, value):
-        # Setting choices also sets the choices on the widget.
-        # choices can be any iterable, but we call list() on it because
-        # it will be consumed more than once.
-        if callable(value):
-            value = CallableChoiceIterator(value)
-        else:
-            value = list(value)
-
-        self._choices = self.widget.choices = value
-
-    choices = property(_get_choices, _set_choices)
+    @choices.setter
+    def choices(self, value):
+        # Setting choices on the field also sets the choices on the widget.
+        # Note that the property setter for the widget will re-normalize.
+        self._choices = self.widget.choices = normalize_choices(value)
 
     def to_python(self, value):
         """Return a string."""

django/forms/models.py

@@ -21,6 +21,7 @@ from django.forms.widgets import (
     RadioSelect,
     SelectMultiple,
 )
+from django.utils.choices import ChoiceIterator
 from django.utils.text import capfirst, get_text_list
 from django.utils.translation import gettext
 from django.utils.translation import gettext_lazy as _
@@ -1402,7 +1403,7 @@ class ModelChoiceIteratorValue:
         return self.value == other
 
 
-class ModelChoiceIterator:
+class ModelChoiceIterator(ChoiceIterator):
     def __init__(self, field):
         self.field = field
         self.queryset = field.queryset
@@ -1532,7 +1533,7 @@ class ModelChoiceField(ChoiceField):
         # the queryset.
         return self.iterator(self)
 
-    choices = property(_get_choices, ChoiceField._set_choices)
+    choices = property(_get_choices, ChoiceField.choices.fset)
 
     def prepare_value(self, value):
         if hasattr(value, "_meta"):

django/forms/widgets.py

@@ -12,6 +12,7 @@ from itertools import chain
 from django.forms.utils import to_current_timezone
 from django.templatetags.static import static
 from django.utils import formats
+from django.utils.choices import normalize_choices
 from django.utils.dates import MONTHS
 from django.utils.formats import get_format
 from django.utils.html import format_html, html_safe
@@ -620,10 +621,7 @@ class ChoiceWidget(Widget):
 
     def __init__(self, attrs=None, choices=()):
         super().__init__(attrs)
-        # choices can be any iterable, but we may need to render this widget
-        # multiple times. Thus, collapse it into a list so it can be consumed
-        # more than once.
-        self.choices = list(choices)
+        self.choices = choices
 
     def __deepcopy__(self, memo):
         obj = copy.copy(self)
@@ -741,6 +739,14 @@ class ChoiceWidget(Widget):
             value = [value]
         return [str(v) if v is not None else "" for v in value]
 
+    @property
+    def choices(self):
+        return self._choices
+
+    @choices.setter
+    def choices(self, value):
+        self._choices = normalize_choices(value)
+
 
 class Select(ChoiceWidget):
     input_type = "select"