Fix encode#7722.

Render BooleanFields with allow_null=True as HTML select rather than as
HTML checkbox in Browsable API encode#7722.

docs/topics/html-and-forms.md

@@ -215,6 +215,7 @@ select.html | `ChoiceField` or relational field types | hide_label
 radio.html | `ChoiceField` or relational field types | inline, hide_label
 select_multiple.html | `MultipleChoiceField` or relational fields with `many=True` | hide_label
 checkbox_multiple.html | `MultipleChoiceField` or relational fields with `many=True` | inline, hide_label
-checkbox.html | `BooleanField` | hide_label
+checkbox.html | `BooleanField` with `allow_null=False` | hide_label
+select_boolean.html | `BooleanField` with `allow_null=True` | hide_label
 fieldset.html | Nested serializer | hide_label
 list_fieldset.html | `ListField` or nested serializer with `many=True` | hide_label

rest_framework/fields.py

@@ -720,6 +720,10 @@ class BooleanField(Field):
  }
  NULL_VALUES = {'null', 'Null', 'NULL', '', None}
 
+ @property
+ def _is_nullable_boolean_field(self):
+ return self.allow_null
+
  def to_internal_value(self, data):
  try:
  if data in self.TRUE_VALUES:
@@ -741,6 +745,14 @@ def to_representation(self, value):
  return None
  return bool(value)
 
+ def iter_options(self):
+ choices = {
+ "": _("Unknown"),
+ True: _("Yes"),
+ False: _("No"),
+ }
+ return iter_options(choices)
+
 
 class NullBooleanField(BooleanField):
  initial = None

rest_framework/renderers.py

@@ -328,8 +328,11 @@ class HTMLFormRenderer(BaseRenderer):
  def render_field(self, field, parent_style):
  if isinstance(field._field, serializers.HiddenField):
  return ''
-
- style = self.default_style[field].copy()
+ is_nullable_boolean_field = isinstance(field._field, serializers.BooleanField) and field._field.allow_null
+ if is_nullable_boolean_field:
+ style = {'base_template': 'select_boolean.html'}
+ else:
+ style = self.default_style[field].copy()
  style.update(field.style)
  if 'template_pack' not in style:
  style['template_pack'] = parent_style.get('template_pack', self.template_pack)

rest_framework/templates/rest_framework/horizontal/select_boolean.html

@@ -0,0 +1,25 @@
+
+<div class="form-group">
+ {% if field.label %}
+ <label class="col-sm-2 control-label {% if style.hide_label %}sr-only{% endif %}">
+ {{ field.label }}
+ </label>
+ {% endif %}
+
+ <div class="col-sm-10">
+ <select class="form-control" name="{{ field.name }}">
+ {% for select in field.iter_options %}
+ <option value="{{ select.value }}" {% if select.value == field.value %}selected{% endif %}>{{ select.display_text }}</option>
+ {% endfor %}
+ </select>
+ {% if field.errors %}
+ {% for error in field.errors %}
+ <span class="help-block">{{ error }}</span>
+ {% endfor %}
+ {% endif %}
+
+ {% if field.help_text %}
+ <span class="help-block">{{ field.help_text|safe }}</span>
+ {% endif %}
+ </div>
+</div>

rest_framework/templates/rest_framework/inline/select_boolean.html

@@ -0,0 +1,15 @@
+{% load rest_framework %}
+
+<div class="form-group {% if field.errors %}has-error{% endif %}">
+ {% if field.label %}
+ <label class="sr-only">
+ {{ field.label }}
+ </label>
+ {% endif %}
+
+ <select class="form-control" name="{{ field.name }}">
+ {% for select in field.iter_options %}
+ <option value="{{ select.value }}" {% if select.value|as_string == field.value|as_string %}selected{% endif %} >{{ select.display_text }}</option>
+ {% endfor %}
+ </select>
+</div>

rest_framework/templates/rest_framework/vertical/select_boolean.html

@@ -0,0 +1,23 @@
+<div class="form-group {% if field.errors %}has-error{% endif %}">
+ {% if field.label %}
+ <label {% if style.hide_label %}class="sr-only"{% endif %}>
+ {{ field.label }}
+ </label>
+ {% endif %}
+
+ <select class="form-control" name="{{ field.name }}">
+ {% for select in field.iter_options %}
+ <option value="{{ select.value }}" {% if select.value == field.value %}selected{% endif %}>{{ select.display_text }}</option>
+ {% endfor %}
+ </select>
+
+ {% if field.errors %}
+ {% for error in field.errors %}
+ <span class="help-block">{{ error }}</span>
+ {% endfor %}
+ {% endif %}
+
+ {% if field.help_text %}
+ <span class="help-block">{{ field.help_text|safe }}</span>
+ {% endif %}
+</div>

rest_framework/utils/serializer_helpers.py

@@ -76,7 +76,10 @@ def __repr__(self):
  )
 
  def as_form_field(self):
- value = '' if (self.value is None or self.value is False) else self.value
+ if getattr(self._field, '_is_nullable_boolean_field', False):
+ value = '' if self.value is None else self.value
+ else:
+ value = '' if (self.value is None or self.value is False) else self.value
  return self.__class__(self._field, value, self.errors, self._prefix)
 
 
@@ -129,6 +132,8 @@ def as_form_field(self):
  for key, value in self.value.items():
  if isinstance(value, (list, dict)):
  values[key] = value
+ elif getattr(self.fields[key], '_is_nullable_boolean_field', False):
+ values[key] = '' if value is None else value
  else:
  values[key] = '' if (value is None or value is False) else force_str(value)
  return self.__class__(self._field, values, self.errors, self._prefix)

tests/test_bound_fields.py

@@ -1,3 +1,4 @@
+import pytest
 from django.http import QueryDict
 
 from rest_framework import serializers
@@ -59,11 +60,13 @@ class ExampleSerializer(serializers.Serializer):
  def test_as_form_fields(self):
  class ExampleSerializer(serializers.Serializer):
  bool_field = serializers.BooleanField()
+ nullable_bool_field = serializers.BooleanField(allow_null=True)
  null_field = serializers.IntegerField(allow_null=True)
 
- serializer = ExampleSerializer(data={'bool_field': False, 'null_field': None})
+ serializer = ExampleSerializer(data={'bool_field': False, 'nullable_bool_field': False, 'null_field': None})
  assert serializer.is_valid()
  assert serializer['bool_field'].as_form_field().value == ''
+ assert serializer['nullable_bool_field'].as_form_field().value is False
  assert serializer['null_field'].as_form_field().value == ''
 
  def test_rendering_boolean_field(self):
@@ -90,6 +93,55 @@ class ExampleSerializer(serializers.Serializer):
  rendered_packed = ''.join(rendered.split())
  assert rendered_packed == expected_packed
 
+ @pytest.mark.parametrize('bool_field_value', [True, False, None])
+ def test_rendering_nullable_boolean_field(self, bool_field_value):
+ from rest_framework.renderers import HTMLFormRenderer
+
+ class ExampleSerializer(serializers.Serializer):
+ bool_field = serializers.BooleanField(
+ allow_null=True,
+ style={'base_template': 'select_boolean.html', 'template_pack': 'rest_framework/vertical'})
+
+ serializer = ExampleSerializer(data={'bool_field': bool_field_value})
+ assert serializer.is_valid()
+ renderer = HTMLFormRenderer()
+ rendered = renderer.render_field(serializer['bool_field'], {})
+ if bool_field_value is True:
+ expected_packed = (
+ '<divclass="form-group">'
+ '<label>Boolfield</label>'
+ '<selectclass="form-control"name="bool_field">'
+ '<optionvalue="">Unknown</option>'
+ '<optionvalue="True"selected>Yes</option>'
+ '<optionvalue="False">No</option>'
+ '</select>'
+ '</div>'
+ )
+ elif bool_field_value is False:
+ expected_packed = (
+ '<divclass="form-group">'
+ '<label>Boolfield</label>'
+ '<selectclass="form-control"name="bool_field">'
+ '<optionvalue="">Unknown</option>'
+ '<optionvalue="True">Yes</option>'
+ '<optionvalue="False"selected>No</option>'
+ '</select>'
+ '</div>'
+ )
+ elif bool_field_value is None:
+ expected_packed = (
+ '<divclass="form-group">'
+ '<label>Boolfield</label>'
+ '<selectclass="form-control"name="bool_field">'
+ '<optionvalue=""selected>Unknown</option>'
+ '<optionvalue="True">Yes</option>'
+ '<optionvalue="False">No</option>'
+ '</select>'
+ '</div>'
+ )
+ rendered_packed = ''.join(rendered.split())
+ assert rendered_packed == expected_packed
+
 
 class CustomJSONField(serializers.JSONField):
  pass
@@ -120,6 +172,7 @@ class ExampleSerializer(serializers.Serializer):
  def test_as_form_fields(self):
  class Nested(serializers.Serializer):
  bool_field = serializers.BooleanField()
+ nullable_bool_field = serializers.BooleanField(allow_null=True)
  null_field = serializers.IntegerField(allow_null=True)
  json_field = serializers.JSONField()
  custom_json_field = CustomJSONField()
@@ -129,12 +182,13 @@ class ExampleSerializer(serializers.Serializer):
 
  serializer = ExampleSerializer(
  data={'nested': {
- 'bool_field': False, 'null_field': None,
+ 'bool_field': False, 'nullable_bool_field': False, 'null_field': None,
  'json_field': {'bool_item': True, 'number': 1, 'text_item': 'text'},
  'custom_json_field': {'bool_item': True, 'number': 1, 'text_item': 'text'},
  }})
  assert serializer.is_valid()
  assert serializer['nested']['bool_field'].as_form_field().value == ''
+ assert serializer['nested']['nullable_bool_field'].as_form_field().value is False
  assert serializer['nested']['null_field'].as_form_field().value == ''
  assert serializer['nested']['json_field'].as_form_field().value == '''{
  "bool_item": true,

tests/test_fields.py

@@ -364,6 +364,8 @@ def test_empty_html_checkbox(self):
  """
  HTML checkboxes do not send any value, but should be treated
  as `False` by BooleanField.
+ Note: BooleanFields are rendered as HTML checkboxes
+ only if allow_null=False.
  """
  class TestSerializer(serializers.Serializer):
  archived = serializers.BooleanField()
@@ -376,6 +378,8 @@ def test_empty_html_checkbox_not_required(self):
  """
  HTML checkboxes do not send any value, but should be treated
  as `False` by BooleanField, even if the field is required=False.
+ Note: BooleanFields are rendered as HTML checkboxes
+ only if allow_null=False.
  """
  class TestSerializer(serializers.Serializer):
  archived = serializers.BooleanField(required=False)
@@ -384,6 +388,22 @@ class TestSerializer(serializers.Serializer):
  assert serializer.is_valid()
  assert serializer.validated_data == {'archived': False}
 
+ @pytest.mark.parametrize(('select_option_value', 'expected_internal_value'), (('', None), ('True', True), ('False', False)))
+ def test_nullable_boolean_html(self, select_option_value, expected_internal_value):
+ """
+ If allow_null=True, BooleanField is rendered as HTML select element
+ containing three option elements with values '', 'True', and 'False'.
+ If option value=False selected, the internal value False is expected.
+ If option value=True selected, the internal value True is expected.
+ If option value= (the empty string) selected, the internal value None is expected.
+ """
+ class TestSerializer(serializers.Serializer):
+ archived = serializers.BooleanField(allow_null=True)
+
+ serializer = TestSerializer(data=QueryDict(f'archived={select_option_value}'))
+ assert serializer.is_valid()
+ assert serializer.validated_data == {'archived': expected_internal_value}
+
 
 class TestHTMLInput:
  def test_empty_html_charfield_with_default(self):