newforms: Implemented NullBooleanField and NullBooleanSelect

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4411 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/newforms/fields.py

@@ -4,7 +4,7 @@ Field classes
 
 from django.utils.translation import gettext
 from util import ErrorList, ValidationError, smart_unicode
-from widgets import TextInput, PasswordInput, HiddenInput, MultipleHiddenInput, CheckboxInput, Select, SelectMultiple
+from widgets import TextInput, PasswordInput, HiddenInput, MultipleHiddenInput, CheckboxInput, Select, NullBooleanSelect, SelectMultiple
 import datetime
 import re
 import time
@@ -15,7 +15,7 @@ __all__ = (
     'DEFAULT_TIME_INPUT_FORMATS', 'TimeField',
     'DEFAULT_DATETIME_INPUT_FORMATS', 'DateTimeField',
     'RegexField', 'EmailField', 'URLField', 'BooleanField',
-    'ChoiceField', 'MultipleChoiceField',
+    'ChoiceField', 'NullBooleanField', 'MultipleChoiceField',
     'ComboField', 'MultiValueField',
     'SplitDateTimeField',
 )
@@ -317,6 +317,16 @@ class BooleanField(Field):
         super(BooleanField, self).clean(value)
         return bool(value)
 
+class NullBooleanField(BooleanField):
+    """
+    A field whose valid values are None, True and False. Invalid values are
+    cleaned to None.
+    """
+    widget = NullBooleanSelect
+
+    def clean(self, value):
+        return {True: True, False: False}.get(value, None)
+
 class ChoiceField(Field):
     def __init__(self, choices=(), required=True, widget=Select, label=None, initial=None):
         if isinstance(widget, type):

django/newforms/widgets.py

@@ -5,13 +5,14 @@ HTML Widget classes
 __all__ = (
     'Widget', 'TextInput', 'PasswordInput', 'HiddenInput', 'MultipleHiddenInput',
     'FileInput', 'Textarea', 'CheckboxInput',
-    'Select', 'SelectMultiple', 'RadioSelect', 'CheckboxSelectMultiple',
+    'Select', 'NullBooleanSelect', 'SelectMultiple', 'RadioSelect', 'CheckboxSelectMultiple',
     'MultiWidget', 'SplitDateTimeWidget',
 )
 
 from util import flatatt, StrAndUnicode, smart_unicode
 from django.utils.datastructures import MultiValueDict
 from django.utils.html import escape
+from django.utils.translation import gettext
 from itertools import chain
 
 try:
@@ -151,6 +152,25 @@ class Select(Widget):
         output.append(u'</select>')
         return u'\n'.join(output)
 
+class NullBooleanSelect(Select):
+    """
+    A Select Widget intended to be used with NullBooleanField.
+    """
+    def __init__(self, attrs=None):
+        choices = ((u'1', gettext('Unknown')), (u'2', gettext('Yes')), (u'3', gettext('No')))
+        super(NullBooleanSelect, self).__init__(attrs, choices)
+
+    def render(self, name, value, attrs=None, choices=()):
+        try:
+            value = {True: u'2', False: u'3', u'2': u'2', u'3': u'3'}[value]
+        except KeyError:
+            value = u'1'
+        return super(NullBooleanSelect, self).render(name, value, attrs, choices)
+
+    def value_from_datadict(self, data, name):
+        value = data.get(name, None)
+        return {u'2': True, u'3': False, True: True, False: False}.get(value, None)
+
 class SelectMultiple(Widget):
     def __init__(self, attrs=None, choices=()):
         # choices can be any iterable

tests/regressiontests/forms/tests.py

@@ -336,6 +336,40 @@ If 'choices' is passed to both the constructor and render(), then they'll both b
 >>> w.render('email', 'ŠĐĆŽćžšđ', choices=[('ŠĐĆŽćžšđ', 'ŠĐabcĆŽćžšđ'), ('ćžšđ', 'abcćžšđ')])
 u'<select name="email">\n<option value="1">1</option>\n<option value="2">2</option>\n<option value="3">3</option>\n<option value="\u0160\u0110\u0106\u017d\u0107\u017e\u0161\u0111" selected="selected">\u0160\u0110abc\u0106\u017d\u0107\u017e\u0161\u0111</option>\n<option value="\u0107\u017e\u0161\u0111">abc\u0107\u017e\u0161\u0111</option>\n</select>'
 
+# NullBooleanSelect Widget ####################################################
+
+>>> w = NullBooleanSelect()
+>>> print w.render('is_cool', True)
+<select name="is_cool">
+<option value="1">Unknown</option>
+<option value="2" selected="selected">Yes</option>
+<option value="3">No</option>
+</select>
+>>> print w.render('is_cool', False)
+<select name="is_cool">
+<option value="1">Unknown</option>
+<option value="2">Yes</option>
+<option value="3" selected="selected">No</option>
+</select>
+>>> print w.render('is_cool', None)
+<select name="is_cool">
+<option value="1" selected="selected">Unknown</option>
+<option value="2">Yes</option>
+<option value="3">No</option>
+</select>
+>>> print w.render('is_cool', '2')
+<select name="is_cool">
+<option value="1">Unknown</option>
+<option value="2" selected="selected">Yes</option>
+<option value="3">No</option>
+</select>
+>>> print w.render('is_cool', '3')
+<select name="is_cool">
+<option value="1">Unknown</option>
+<option value="2">Yes</option>
+<option value="3" selected="selected">No</option>
+</select>
+
 # SelectMultiple Widget #######################################################
 
 >>> w = SelectMultiple()
@@ -1463,6 +1497,20 @@ Traceback (most recent call last):
 ...
 ValidationError: [u'Select a valid choice. John is not one of the available choices.']
 
+# NullBooleanField ############################################################
+
+>>> f = NullBooleanField()
+>>> f.clean('')
+>>> f.clean(True)
+True
+>>> f.clean(False)
+False
+>>> f.clean(None)
+>>> f.clean('1')
+>>> f.clean('2')
+>>> f.clean('3')
+>>> f.clean('hello')
+
 # MultipleChoiceField #########################################################
 
 >>> f = MultipleChoiceField(choices=[('1', '1'), ('2', '2')])
@@ -2601,6 +2649,57 @@ True
 >>> p.clean_data
 {'first_name': u'John', 'last_name': u'Lennon', 'birthday': datetime.date(1940, 10, 9)}
 
+# Forms with NullBooleanFields ################################################
+
+NullBooleanField is a bit of a special case because its presentation (widget)
+is different than its data. This is handled transparently, though.
+
+>>> class Person(Form):
+...     name = CharField()
+...     is_cool = NullBooleanField()
+>>> p = Person({'name': u'Joe'}, auto_id=False)
+>>> print p['is_cool']
+<select name="is_cool">
+<option value="1" selected="selected">Unknown</option>
+<option value="2">Yes</option>
+<option value="3">No</option>
+</select>
+>>> p = Person({'name': u'Joe', 'is_cool': u'1'}, auto_id=False)
+>>> print p['is_cool']
+<select name="is_cool">
+<option value="1" selected="selected">Unknown</option>
+<option value="2">Yes</option>
+<option value="3">No</option>
+</select>
+>>> p = Person({'name': u'Joe', 'is_cool': u'2'}, auto_id=False)
+>>> print p['is_cool']
+<select name="is_cool">
+<option value="1">Unknown</option>
+<option value="2" selected="selected">Yes</option>
+<option value="3">No</option>
+</select>
+>>> p = Person({'name': u'Joe', 'is_cool': u'3'}, auto_id=False)
+>>> print p['is_cool']
+<select name="is_cool">
+<option value="1">Unknown</option>
+<option value="2">Yes</option>
+<option value="3" selected="selected">No</option>
+</select>
+>>> p = Person({'name': u'Joe', 'is_cool': True}, auto_id=False)
+>>> print p['is_cool']
+<select name="is_cool">
+<option value="1">Unknown</option>
+<option value="2" selected="selected">Yes</option>
+<option value="3">No</option>
+</select>
+>>> p = Person({'name': u'Joe', 'is_cool': False}, auto_id=False)
+>>> print p['is_cool']
+<select name="is_cool">
+<option value="1">Unknown</option>
+<option value="2">Yes</option>
+<option value="3" selected="selected">No</option>
+</select>
+
 # Basic form processing in a view #############################################
 
 >>> from django.template import Template, Context