per-object-permissions: Merged to trunk [5486] NOTE: Not fully tested, will be working on this over the next few weeks.

git-svn-id: http://code.djangoproject.com/svn/django/branches/per-object-permissions@5488 bcc190cf-cafb-0310-a4f2-bffc1f526a37

6 files changed, 689 insertions, 155 deletions

diff --git a/django/newforms/extras/widgets.py b/django/newforms/extras/widgets.py
index 1011934fb8..724dcd9b50 100644
--- a/django/newforms/extras/widgets.py
+++ b/django/newforms/extras/widgets.py
@@ -2,9 +2,10 @@
 Extra HTML Widget classes
 """
 
+import datetime
+
 from django.newforms.widgets import Widget, Select
 from django.utils.dates import MONTHS
-import datetime
 
 __all__ = ('SelectDateWidget',)
 
diff --git a/django/newforms/fields.py b/django/newforms/fields.py
index 5c6d46ddac..b73dd181e6 100644
--- a/django/newforms/fields.py
+++ b/django/newforms/fields.py
@@ -2,21 +2,25 @@
 Field classes
 """
 
-from django.utils.translation import gettext
-from util import ValidationError, smart_unicode
-from widgets import TextInput, PasswordInput, CheckboxInput, Select, SelectMultiple
 import datetime
 import re
 import time
 
+from django.utils.translation import gettext
+from django.utils.encoding import smart_unicode
+
+from util import ErrorList, ValidationError
+from widgets import TextInput, PasswordInput, HiddenInput, MultipleHiddenInput, CheckboxInput, Select, NullBooleanSelect, SelectMultiple
+
 __all__ = (
     'Field', 'CharField', 'IntegerField',
     'DEFAULT_DATE_INPUT_FORMATS', 'DateField',
     'DEFAULT_TIME_INPUT_FORMATS', 'TimeField',
     'DEFAULT_DATETIME_INPUT_FORMATS', 'DateTimeField',
     'RegexField', 'EmailField', 'URLField', 'BooleanField',
-    'ChoiceField', 'MultipleChoiceField',
-    'ComboField',
+    'ChoiceField', 'NullBooleanField', 'MultipleChoiceField',
+    'ComboField', 'MultiValueField', 'FloatField', 'DecimalField',
+    'SplitDateTimeField',
 )
 
 # These values, if given to to_python(), will trigger the self.required check.
@@ -27,16 +31,36 @@ try:
 except NameError:
     from sets import Set as set # Python 2.3 fallback
 
+try:
+    from decimal import Decimal
+except ImportError:
+    from django.utils._decimal import Decimal   # Python 2.3 fallback
+
 class Field(object):
     widget = TextInput # Default widget to use when rendering this type of Field.
+    hidden_widget = HiddenInput # Default widget to use when rendering this as "hidden".
 
     # Tracks each time a Field instance is created. Used to retain order.
     creation_counter = 0
 
-    def __init__(self, required=True, widget=None, label=None):
+    def __init__(self, required=True, widget=None, label=None, initial=None, help_text=None):
+        # required -- Boolean that specifies whether the field is required.
+        #             True by default.
+        # widget -- A Widget class, or instance of a Widget class, that should
+        #           be used for this Field when displaying it. Each Field has a
+        #           default Widget that it'll use if you don't specify this. In
+        #           most cases, the default widget is TextInput.
+        # label -- A verbose name for this field, for use in displaying this
+        #          field in a form. By default, Django will use a "pretty"
+        #          version of the form field name, if the Field is part of a
+        #          Form.
+        # initial -- A value to use in this Field's initial display. This value
+        #            is *not* used as a fallback if data isn't given.
+        # help_text -- An optional string to use as "help text" for this Field.
         if label is not None:
             label = smart_unicode(label)
-        self.required, self.label = required, label
+        self.required, self.label, self.initial = required, label, initial
+        self.help_text = smart_unicode(help_text or '')
         widget = widget or self.widget
         if isinstance(widget, type):
             widget = widget()
@@ -72,17 +96,15 @@ class Field(object):
         return {}
 
 class CharField(Field):
-    def __init__(self, max_length=None, min_length=None, required=True, widget=None, label=None):
+    def __init__(self, max_length=None, min_length=None, *args, **kwargs):
         self.max_length, self.min_length = max_length, min_length
-        Field.__init__(self, required, widget, label)
+        super(CharField, self).__init__(*args, **kwargs)
 
     def clean(self, value):
         "Validates max_length and min_length. Returns a Unicode object."
-        Field.clean(self, value)
+        super(CharField, self).clean(value)
         if value in EMPTY_VALUES:
-            value = u''
-            if not self.required:
-                return value
+            return u''
         value = smart_unicode(value)
         if self.max_length is not None and len(value) > self.max_length:
             raise ValidationError(gettext(u'Ensure this value has at most %d characters.') % self.max_length)
@@ -95,18 +117,18 @@ class CharField(Field):
             return {'maxlength': str(self.max_length)}
 
 class IntegerField(Field):
-    def __init__(self, max_value=None, min_value=None, required=True, widget=None, label=None):
+    def __init__(self, max_value=None, min_value=None, *args, **kwargs):
         self.max_value, self.min_value = max_value, min_value
-        Field.__init__(self, required, widget, label)
+        super(IntegerField, self).__init__(*args, **kwargs)
 
     def clean(self, value):
         """
         Validates that int() can be called on the input. Returns the result
-        of int().
+        of int(). Returns None for empty values.
         """
         super(IntegerField, self).clean(value)
-        if not self.required and value in EMPTY_VALUES:
-            return u''
+        if value in EMPTY_VALUES:
+            return None
         try:
             value = int(value)
         except (ValueError, TypeError):
@@ -117,6 +139,67 @@ class IntegerField(Field):
             raise ValidationError(gettext(u'Ensure this value is greater than or equal to %s.') % self.min_value)
         return value
 
+class FloatField(Field):
+    def __init__(self, max_value=None, min_value=None, *args, **kwargs):
+        self.max_value, self.min_value = max_value, min_value
+        Field.__init__(self, *args, **kwargs)
+
+    def clean(self, value):
+        """
+        Validates that float() can be called on the input. Returns a float.
+        Returns None for empty values.
+        """
+        super(FloatField, self).clean(value)
+        if not self.required and value in EMPTY_VALUES:
+            return None
+        try:
+            value = float(value)
+        except (ValueError, TypeError):
+            raise ValidationError(gettext('Enter a number.'))
+        if self.max_value is not None and value > self.max_value:
+            raise ValidationError(gettext('Ensure this value is less than or equal to %s.') % self.max_value)
+        if self.min_value is not None and value < self.min_value:
+            raise ValidationError(gettext('Ensure this value is greater than or equal to %s.') % self.min_value)
+        return value
+
+decimal_re = re.compile(r'^-?(?P<digits>\d+)(\.(?P<decimals>\d+))?$')
+
+class DecimalField(Field):
+    def __init__(self, max_value=None, min_value=None, max_digits=None, decimal_places=None, *args, **kwargs):
+        self.max_value, self.min_value = max_value, min_value
+        self.max_digits, self.decimal_places = max_digits, decimal_places
+        Field.__init__(self, *args, **kwargs)
+
+    def clean(self, value):
+        """
+        Validates that the input is a decimal number. Returns a Decimal
+        instance. Returns None for empty values. Ensures that there are no more
+        than max_digits in the number, and no more than decimal_places digits
+        after the decimal point.
+        """
+        super(DecimalField, self).clean(value)
+        if not self.required and value in EMPTY_VALUES:
+            return None
+        value = value.strip()
+        match = decimal_re.search(value)
+        if not match:
+            raise ValidationError(gettext('Enter a number.'))
+        else:
+            value = Decimal(value)
+        digits = len(match.group('digits') or '')
+        decimals = len(match.group('decimals') or '')
+        if self.max_value is not None and value > self.max_value:
+            raise ValidationError(gettext('Ensure this value is less than or equal to %s.') % self.max_value)
+        if self.min_value is not None and value < self.min_value:
+            raise ValidationError(gettext('Ensure this value is greater than or equal to %s.') % self.min_value)
+        if self.max_digits is not None and (digits + decimals) > self.max_digits:
+            raise ValidationError(gettext('Ensure that there are no more than %s digits in total.') % self.max_digits)
+        if self.decimal_places is not None and decimals > self.decimal_places:
+            raise ValidationError(gettext('Ensure that there are no more than %s decimal places.') % self.decimal_places)
+        if self.max_digits is not None and self.decimal_places is not None and digits > (self.max_digits - self.decimal_places):
+            raise ValidationError(gettext('Ensure that there are no more than %s digits before the decimal point.') % (self.max_digits - self.decimal_places))
+        return value
+
 DEFAULT_DATE_INPUT_FORMATS = (
     '%Y-%m-%d', '%m/%d/%Y', '%m/%d/%y', # '2006-10-25', '10/25/2006', '10/25/06'
     '%b %d %Y', '%b %d, %Y',            # 'Oct 25 2006', 'Oct 25, 2006'
@@ -126,8 +209,8 @@ DEFAULT_DATE_INPUT_FORMATS = (
 )
 
 class DateField(Field):
-    def __init__(self, input_formats=None, required=True, widget=None, label=None):
-        Field.__init__(self, required, widget, label)
+    def __init__(self, input_formats=None, *args, **kwargs):
+        super(DateField, self).__init__(*args, **kwargs)
         self.input_formats = input_formats or DEFAULT_DATE_INPUT_FORMATS
 
     def clean(self, value):
@@ -135,7 +218,7 @@ class DateField(Field):
         Validates that the input can be converted to a date. Returns a Python
         datetime.date object.
         """
-        Field.clean(self, value)
+        super(DateField, self).clean(value)
         if value in EMPTY_VALUES:
             return None
         if isinstance(value, datetime.datetime):
@@ -155,8 +238,8 @@ DEFAULT_TIME_INPUT_FORMATS = (
 )
 
 class TimeField(Field):
-    def __init__(self, input_formats=None, required=True, widget=None, label=None):
-        Field.__init__(self, required, widget, label)
+    def __init__(self, input_formats=None, *args, **kwargs):
+        super(TimeField, self).__init__(*args, **kwargs)
         self.input_formats = input_formats or DEFAULT_TIME_INPUT_FORMATS
 
     def clean(self, value):
@@ -164,7 +247,7 @@ class TimeField(Field):
         Validates that the input can be converted to a time. Returns a Python
         datetime.time object.
         """
-        Field.clean(self, value)
+        super(TimeField, self).clean(value)
         if value in EMPTY_VALUES:
             return None
         if isinstance(value, datetime.time):
@@ -189,8 +272,8 @@ DEFAULT_DATETIME_INPUT_FORMATS = (
 )
 
 class DateTimeField(Field):
-    def __init__(self, input_formats=None, required=True, widget=None, label=None):
-        Field.__init__(self, required, widget, label)
+    def __init__(self, input_formats=None, *args, **kwargs):
+        super(DateTimeField, self).__init__(*args, **kwargs)
         self.input_formats = input_formats or DEFAULT_DATETIME_INPUT_FORMATS
 
     def clean(self, value):
@@ -198,7 +281,7 @@ class DateTimeField(Field):
         Validates that the input can be converted to a datetime. Returns a
         Python datetime.datetime object.
         """
-        Field.clean(self, value)
+        super(DateTimeField, self).clean(value)
         if value in EMPTY_VALUES:
             return None
         if isinstance(value, datetime.datetime):
@@ -213,14 +296,13 @@ class DateTimeField(Field):
         raise ValidationError(gettext(u'Enter a valid date/time.'))
 
 class RegexField(Field):
-    def __init__(self, regex, max_length=None, min_length=None, error_message=None,
-            required=True, widget=None, label=None):
+    def __init__(self, regex, max_length=None, min_length=None, error_message=None, *args, **kwargs):
         """
         regex can be either a string or a compiled regular expression object.
         error_message is an optional error message to use, if
         'Enter a valid value' is too generic for you.
         """
-        Field.__init__(self, required, widget, label)
+        super(RegexField, self).__init__(*args, **kwargs)
         if isinstance(regex, basestring):
             regex = re.compile(regex)
         self.regex = regex
@@ -232,10 +314,11 @@ class RegexField(Field):
         Validates that the input matches the regular expression. Returns a
         Unicode object.
         """
-        Field.clean(self, value)
-        if value in EMPTY_VALUES: value = u''
+        super(RegexField, self).clean(value)
+        if value in EMPTY_VALUES:
+            value = u''
         value = smart_unicode(value)
-        if not self.required and value == u'':
+        if value == u'':
             return value
         if self.max_length is not None and len(value) > self.max_length:
             raise ValidationError(gettext(u'Ensure this value has at most %d characters.') % self.max_length)
@@ -251,8 +334,9 @@ email_re = re.compile(
     r')@(?:[A-Z0-9-]+\.)+[A-Z]{2,6}$', re.IGNORECASE)  # domain
 
 class EmailField(RegexField):
-    def __init__(self, max_length=None, min_length=None, required=True, widget=None, label=None):
-        RegexField.__init__(self, email_re, max_length, min_length, gettext(u'Enter a valid e-mail address.'), required, widget, label)
+    def __init__(self, max_length=None, min_length=None, *args, **kwargs):
+        RegexField.__init__(self, email_re, max_length, min_length,
+            gettext(u'Enter a valid e-mail address.'), *args, **kwargs)
 
 url_re = re.compile(
     r'^https?://' # http:// or https://
@@ -268,14 +352,16 @@ except ImportError:
     URL_VALIDATOR_USER_AGENT = 'Django (http://www.djangoproject.com/)'
 
 class URLField(RegexField):
-    def __init__(self, max_length=None, min_length=None, required=True, verify_exists=False, widget=None, label=None,
-            validator_user_agent=URL_VALIDATOR_USER_AGENT):
-        RegexField.__init__(self, url_re, max_length, min_length, gettext(u'Enter a valid URL.'), required, widget, label)
+    def __init__(self, max_length=None, min_length=None, verify_exists=False,
+            validator_user_agent=URL_VALIDATOR_USER_AGENT, *args, **kwargs):
+        super(URLField, self).__init__(url_re, max_length, min_length, gettext(u'Enter a valid URL.'), *args, **kwargs)
         self.verify_exists = verify_exists
         self.user_agent = validator_user_agent
 
     def clean(self, value):
-        value = RegexField.clean(self, value)
+        value = super(URLField, self).clean(value)
+        if value == u'':
+            return value
         if self.verify_exists:
             import urllib2
             from django.conf import settings
@@ -300,33 +386,55 @@ class BooleanField(Field):
 
     def clean(self, value):
         "Returns a Python boolean object."
-        Field.clean(self, value)
+        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):
-        if isinstance(widget, type):
-            widget = widget(choices=choices)
-        Field.__init__(self, required, widget, label)
+    widget = Select
+
+    def __init__(self, choices=(), required=True, widget=None, label=None, initial=None, help_text=None):
+        super(ChoiceField, self).__init__(required, widget, label, initial, help_text)
         self.choices = choices
 
+    def _get_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.
+        self._choices = self.widget.choices = list(value)
+
+    choices = property(_get_choices, _set_choices)
+
     def clean(self, value):
         """
         Validates that the input is in self.choices.
         """
-        value = Field.clean(self, value)
-        if value in EMPTY_VALUES: value = u''
+        value = super(ChoiceField, self).clean(value)
+        if value in EMPTY_VALUES:
+            value = u''
         value = smart_unicode(value)
-        if not self.required and value == u'':
+        if value == u'':
             return value
         valid_values = set([str(k) for k, v in self.choices])
         if value not in valid_values:
-            raise ValidationError(gettext(u'Select a valid choice. %s is not one of the available choices.') % value)
+            raise ValidationError(gettext(u'Select a valid choice. That choice is not one of the available choices.'))
         return value
 
 class MultipleChoiceField(ChoiceField):
-    def __init__(self, choices=(), required=True, widget=SelectMultiple, label=None):
-        ChoiceField.__init__(self, choices, required, widget, label)
+    hidden_widget = MultipleHiddenInput
+    widget = SelectMultiple
 
     def clean(self, value):
         """
@@ -350,8 +458,11 @@ class MultipleChoiceField(ChoiceField):
         return new_value
 
 class ComboField(Field):
-    def __init__(self, fields=(), required=True, widget=None, label=None):
-        Field.__init__(self, required, widget, label)
+    """
+    A Field whose clean() method calls multiple Field clean() methods.
+    """
+    def __init__(self, fields=(), *args, **kwargs):
+        super(ComboField, self).__init__(*args, **kwargs)
         # Set 'required' to False on the individual fields, because the
         # required validation will be handled by ComboField, not by those
         # individual fields.
@@ -364,7 +475,88 @@ class ComboField(Field):
         Validates the given value against all of self.fields, which is a
         list of Field instances.
         """
-        Field.clean(self, value)
+        super(ComboField, self).clean(value)
         for field in self.fields:
             value = field.clean(value)
         return value
+
+class MultiValueField(Field):
+    """
+    A Field that is composed of multiple Fields.
+
+    Its clean() method takes a "decompressed" list of values. Each value in
+    this list is cleaned by the corresponding field -- the first value is
+    cleaned by the first field, the second value is cleaned by the second
+    field, etc. Once all fields are cleaned, the list of clean values is
+    "compressed" into a single value.
+
+    Subclasses should implement compress(), which specifies how a list of
+    valid values should be converted to a single value. Subclasses should not
+    have to implement clean().
+
+    You'll probably want to use this with MultiWidget.
+    """
+    def __init__(self, fields=(), *args, **kwargs):
+        super(MultiValueField, self).__init__(*args, **kwargs)
+        # Set 'required' to False on the individual fields, because the
+        # required validation will be handled by MultiValueField, not by those
+        # individual fields.
+        for f in fields:
+            f.required = False
+        self.fields = fields
+
+    def clean(self, value):
+        """
+        Validates every value in the given list. A value is validated against
+        the corresponding Field in self.fields.
+
+        For example, if this MultiValueField was instantiated with
+        fields=(DateField(), TimeField()), clean() would call
+        DateField.clean(value[0]) and TimeField.clean(value[1]).
+        """
+        clean_data = []
+        errors = ErrorList()
+        if self.required and not value:
+            raise ValidationError(gettext(u'This field is required.'))
+        elif not self.required and not value:
+            return self.compress([])
+        if not isinstance(value, (list, tuple)):
+            raise ValidationError(gettext(u'Enter a list of values.'))
+        for i, field in enumerate(self.fields):
+            try:
+                field_value = value[i]
+            except IndexError:
+                field_value = None
+            if self.required and field_value in EMPTY_VALUES:
+                raise ValidationError(gettext(u'This field is required.'))
+            try:
+                clean_data.append(field.clean(field_value))
+            except ValidationError, e:
+                # Collect all validation errors in a single list, which we'll
+                # raise at the end of clean(), rather than raising a single
+                # exception for the first error we encounter.
+                errors.extend(e.messages)
+        if errors:
+            raise ValidationError(errors)
+        return self.compress(clean_data)
+
+    def compress(self, data_list):
+        """
+        Returns a single value for the given list of values. The values can be
+        assumed to be valid.
+
+        For example, if this MultiValueField was instantiated with
+        fields=(DateField(), TimeField()), this might return a datetime
+        object created by combining the date and time in data_list.
+        """
+        raise NotImplementedError('Subclasses must implement this method.')
+
+class SplitDateTimeField(MultiValueField):
+    def __init__(self, *args, **kwargs):
+        fields = (DateField(), TimeField())
+        super(SplitDateTimeField, self).__init__(fields, *args, **kwargs)
+
+    def compress(self, data_list):
+        if data_list:
+            return datetime.datetime.combine(*data_list)
+        return None
diff --git a/django/newforms/forms.py b/django/newforms/forms.py
index 201cce3868..6ebebded4b 100644
--- a/django/newforms/forms.py
+++ b/django/newforms/forms.py
@@ -2,11 +2,15 @@
 Form classes
 """
 
-from django.utils.datastructures import SortedDict, MultiValueDict
+import copy
+
+from django.utils.datastructures import SortedDict
 from django.utils.html import escape
+from django.utils.encoding import StrAndUnicode
+
 from fields import Field
-from widgets import TextInput, Textarea, HiddenInput
-from util import StrAndUnicode, ErrorDict, ErrorList, ValidationError
+from widgets import TextInput, Textarea
+from util import flatatt, ErrorDict, ErrorList, ValidationError
 
 __all__ = ('BaseForm', 'Form')
 
@@ -26,12 +30,26 @@ class SortedDictFromList(SortedDict):
         self.keyOrder = [d[0] for d in data]
         dict.__init__(self, dict(data))
 
+    def copy(self):
+        return SortedDictFromList([(k, copy.copy(v)) for k, v in self.items()])
+
 class DeclarativeFieldsMetaclass(type):
-    "Metaclass that converts Field attributes to a dictionary called 'fields'."
+    """
+    Metaclass that converts Field attributes to a dictionary called
+    'base_fields', taking into account parent class 'base_fields' as well.
+    """
     def __new__(cls, name, bases, attrs):
-        fields = [(name, attrs.pop(name)) for name, obj in attrs.items() if isinstance(obj, Field)]
+        fields = [(field_name, attrs.pop(field_name)) for field_name, obj in attrs.items() if isinstance(obj, Field)]
         fields.sort(lambda x, y: cmp(x[1].creation_counter, y[1].creation_counter))
-        attrs['fields'] = SortedDictFromList(fields)
+
+        # If this class is subclassing another Form, add that Form's fields.
+        # Note that we loop over the bases in *reverse*. This is necessary in
+        # order to preserve the correct order of fields.
+        for base in bases[::-1]:
+            if hasattr(base, 'base_fields'):
+                fields = base.base_fields.items() + fields
+
+        attrs['base_fields'] = SortedDictFromList(fields)
         return type.__new__(cls, name, bases, attrs)
 
 class BaseForm(StrAndUnicode):
@@ -39,13 +57,20 @@ class BaseForm(StrAndUnicode):
     # class is different than Form. See the comments by the Form class for more
     # information. Any improvements to the form API should be made to *this*
     # class, not to the Form class.
-    def __init__(self, data=None, auto_id='id_%s', prefix=None):
-        self.ignore_errors = data is None
+    def __init__(self, data=None, auto_id='id_%s', prefix=None, initial=None):
+        self.is_bound = data is not None
         self.data = data or {}
         self.auto_id = auto_id
         self.prefix = prefix
-        self.clean_data = None # Stores the data after clean() has been called.
-        self.__errors = None # Stores the errors after clean() has been called.
+        self.initial = initial or {}
+        self._errors = None # Stores the errors after clean() has been called.
+
+        # The base_fields class attribute is the *class-wide* definition of
+        # fields. Because a particular *instance* of the class might want to
+        # alter self.fields, we create self.fields here by copying base_fields.
+        # Instances should always modify self.fields; they should not modify
+        # self.base_fields.
+        self.fields = self.base_fields.copy()
 
     def __unicode__(self):
         return self.as_table()
@@ -62,19 +87,19 @@ class BaseForm(StrAndUnicode):
             raise KeyError('Key %r not found in Form' % name)
         return BoundField(self, field, name)
 
-    def _errors(self):
+    def _get_errors(self):
         "Returns an ErrorDict for self.data"
-        if self.__errors is None:
+        if self._errors is None:
             self.full_clean()
-        return self.__errors
-    errors = property(_errors)
+        return self._errors
+    errors = property(_get_errors)
 
     def is_valid(self):
         """
         Returns True if the form has no errors. Otherwise, False. If errors are
         being ignored, returns False.
         """
-        return not self.ignore_errors and not bool(self.errors)
+        return self.is_bound and not bool(self.errors)
 
     def add_prefix(self, field_name):
         """
@@ -85,13 +110,13 @@ class BaseForm(StrAndUnicode):
         """
         return self.prefix and ('%s-%s' % (self.prefix, field_name)) or field_name
 
-    def _html_output(self, normal_row, error_row, row_ender, errors_on_separate_row):
+    def _html_output(self, normal_row, error_row, row_ender, help_text_html, errors_on_separate_row):
         "Helper function for outputting HTML. Used by as_table(), as_ul(), as_p()."
         top_errors = self.non_field_errors() # Errors that should be displayed above all fields.
         output, hidden_fields = [], []
         for name, field in self.fields.items():
             bf = BoundField(self, field, name)
-            bf_errors = bf.errors # Cache in local variable.
+            bf_errors = ErrorList([escape(error) for error in bf.errors]) # Escape and cache in local variable.
             if bf.is_hidden:
                 if bf_errors:
                     top_errors.extend(['(Hidden field %s) %s' % (name, e) for e in bf_errors])
@@ -99,8 +124,19 @@ class BaseForm(StrAndUnicode):
             else:
                 if errors_on_separate_row and bf_errors:
                     output.append(error_row % bf_errors)
-                label = bf.label and bf.label_tag(escape(bf.label + ':')) or ''
-                output.append(normal_row % {'errors': bf_errors, 'label': label, 'field': bf})
+                if bf.label:
+                    label = escape(bf.label)
+                    # Only add a colon if the label does not end in punctuation.
+                    if label[-1] not in ':?.!':
+                        label += ':'
+                    label = bf.label_tag(label) or ''
+                else:
+                    label = ''
+                if field.help_text:
+                    help_text = help_text_html % field.help_text
+                else:
+                    help_text = u''
+                output.append(normal_row % {'errors': bf_errors, 'label': label, 'field': unicode(bf), 'help_text': help_text})
         if top_errors:
             output.insert(0, error_row % top_errors)
         if hidden_fields: # Insert any hidden fields in the last row.
@@ -115,15 +151,15 @@ class BaseForm(StrAndUnicode):
 
     def as_table(self):
         "Returns this form rendered as HTML <tr>s -- excluding the <table></table>."
-        return self._html_output(u'<tr><th>%(label)s</th><td>%(errors)s%(field)s</td></tr>', u'<tr><td colspan="2">%s</td></tr>', '</td></tr>', False)
+        return self._html_output(u'<tr><th>%(label)s</th><td>%(errors)s%(field)s%(help_text)s</td></tr>', u'<tr><td colspan="2">%s</td></tr>', '</td></tr>', u'<br />%s', False)
 
     def as_ul(self):
         "Returns this form rendered as HTML <li>s -- excluding the <ul></ul>."
-        return self._html_output(u'<li>%(errors)s%(label)s %(field)s</li>', u'<li>%s</li>', '</li>', False)
+        return self._html_output(u'<li>%(errors)s%(label)s %(field)s%(help_text)s</li>', u'<li>%s</li>', '</li>', u' %s', False)
 
     def as_p(self):
         "Returns this form rendered as HTML <p>s."
-        return self._html_output(u'<p>%(label)s %(field)s</p>', u'<p>%s</p>', '</p>', True)
+        return self._html_output(u'<p>%(label)s %(field)s%(help_text)s</p>', u'<p>%s</p>', '</p>', u' %s', True)
 
     def non_field_errors(self):
         """
@@ -135,13 +171,13 @@ class BaseForm(StrAndUnicode):
 
     def full_clean(self):
         """
-        Cleans all of self.data and populates self.__errors and self.clean_data.
+        Cleans all of self.data and populates self._errors and
+        self.cleaned_data.
         """
-        self.clean_data = {}
-        errors = ErrorDict()
-        if self.ignore_errors: # Stop further processing.
-            self.__errors = errors
+        self._errors = ErrorDict()
+        if not self.is_bound: # Stop further processing.
             return
+        self.cleaned_data = {}
         for name, field in self.fields.items():
             # value_from_datadict() gets the data from the dictionary.
             # Each widget type knows how to retrieve its own data, because some
@@ -149,19 +185,20 @@ class BaseForm(StrAndUnicode):
             value = field.widget.value_from_datadict(self.data, self.add_prefix(name))
             try:
                 value = field.clean(value)
-                self.clean_data[name] = value
+                self.cleaned_data[name] = value
                 if hasattr(self, 'clean_%s' % name):
                     value = getattr(self, 'clean_%s' % name)()
-                self.clean_data[name] = value
+                    self.cleaned_data[name] = value
             except ValidationError, e:
-                errors[name] = e.messages
+                self._errors[name] = e.messages
+                if name in self.cleaned_data:
+                    del self.cleaned_data[name]
         try:
-            self.clean_data = self.clean()
+            self.cleaned_data = self.clean()
         except ValidationError, e:
-            errors[NON_FIELD_ERRORS] = e.messages
-        if errors:
-            self.clean_data = None
-        self.__errors = errors
+            self._errors[NON_FIELD_ERRORS] = e.messages
+        if self._errors:
+            delattr(self, 'cleaned_data')
 
     def clean(self):
         """
@@ -170,7 +207,7 @@ class BaseForm(StrAndUnicode):
         not be associated with a particular field; it will have a special-case
         association with the field named '__all__'.
         """
-        return self.clean_data
+        return self.cleaned_data
 
 class Form(BaseForm):
     "A collection of Fields, plus their associated data."
@@ -192,6 +229,7 @@ class BoundField(StrAndUnicode):
             self.label = pretty_name(name)
         else:
             self.label = self.field.label
+        self.help_text = field.help_text or ''
 
     def __unicode__(self):
         "Renders this field as an HTML widget."
@@ -200,9 +238,9 @@ class BoundField(StrAndUnicode):
         value = self.as_widget(self.field.widget)
         if not isinstance(value, basestring):
             # Some Widget render() methods -- notably RadioSelect -- return a
-            # "special" object rather than a string. Call the __str__() on that
+            # "special" object rather than a string. Call __unicode__() on that
             # object to get its rendered value.
-            value = value.__str__()
+            value = unicode(value)
         return value
 
     def _errors(self):
@@ -216,9 +254,15 @@ class BoundField(StrAndUnicode):
     def as_widget(self, widget, attrs=None):
         attrs = attrs or {}
         auto_id = self.auto_id
-        if auto_id and not attrs.has_key('id') and not widget.attrs.has_key('id'):
+        if auto_id and 'id' not in attrs and 'id' not in widget.attrs:
             attrs['id'] = auto_id
-        return widget.render(self.html_name, self.data, attrs=attrs)
+        if not self.form.is_bound:
+            data = self.form.initial.get(self.name, self.field.initial)
+            if callable(data):
+                data = data()
+        else:
+            data = self.data
+        return widget.render(self.html_name, data, attrs=attrs)
 
     def as_text(self, attrs=None):
         """
@@ -234,24 +278,29 @@ class BoundField(StrAndUnicode):
         """
         Returns a string of HTML for representing this as an <input type="hidden">.
         """
-        return self.as_widget(HiddenInput(), attrs)
+        return self.as_widget(self.field.hidden_widget(), attrs)
 
     def _data(self):
-        "Returns the data for this BoundField, or None if it wasn't given."
+        """
+        Returns the data for this BoundField, or None if it wasn't given.
+        """
         return self.field.widget.value_from_datadict(self.form.data, self.html_name)
     data = property(_data)
 
-    def label_tag(self, contents=None):
+    def label_tag(self, contents=None, attrs=None):
         """
         Wraps the given contents in a <label>, if the field has an ID attribute.
         Does not HTML-escape the contents. If contents aren't given, uses the
         field's HTML-escaped label.
+
+        If attrs are given, they're used as HTML attributes on the <label> tag.
         """
         contents = contents or escape(self.label)
         widget = self.field.widget
         id_ = widget.attrs.get('id') or self.auto_id
         if id_:
-            contents = '<label for="%s">%s</label>' % (widget.id_for_label(id_), contents)
+            attrs = attrs and flatatt(attrs) or ''
+            contents = '<label for="%s"%s>%s</label>' % (widget.id_for_label(id_), attrs, contents)
         return contents
 
     def _is_hidden(self):
diff --git a/django/newforms/models.py b/django/newforms/models.py
index 6b111d7ee1..d51b06c78c 100644
--- a/django/newforms/models.py
+++ b/django/newforms/models.py
@@ -3,36 +3,196 @@ Helper functions for creating Form classes from Django models
 and database field objects.
 """
 
-from forms import BaseForm, DeclarativeFieldsMetaclass, SortedDictFromList
+from django.utils.translation import gettext
 
-__all__ = ('form_for_model', 'form_for_fields')
+from util import ValidationError
+from forms import BaseForm, SortedDictFromList
+from fields import Field, ChoiceField
+from widgets import Select, SelectMultiple, MultipleHiddenInput
 
-def create(self, save=True):
-    "Creates and returns model instance according to self.clean_data."
-    if self.errors:
-        raise ValueError("The %s could not be created because the data didn't validate." % self._model._meta.object_name)
-    obj = self._model(**self.clean_data)
-    if save:
-        obj.save()
-    return obj
+__all__ = (
+    'save_instance', 'form_for_model', 'form_for_instance', 'form_for_fields',
+    'ModelChoiceField', 'ModelMultipleChoiceField'
+)
 
-def form_for_model(model, form=None):
+def save_instance(form, instance, fields=None, fail_message='saved', commit=True):
+    """
+    Saves bound Form ``form``'s cleaned_data into model instance ``instance``.
+
+    If commit=True, then the changes to ``instance`` will be saved to the
+    database. Returns ``instance``.
+    """
+    from django.db import models
+    opts = instance.__class__._meta
+    if form.errors:
+        raise ValueError("The %s could not be %s because the data didn't validate." % (opts.object_name, fail_message))
+    cleaned_data = form.cleaned_data
+    for f in opts.fields:
+        if not f.editable or isinstance(f, models.AutoField) or not f.name in cleaned_data:
+            continue
+        if fields and f.name not in fields:
+            continue
+        setattr(instance, f.name, cleaned_data[f.name])
+    if commit:
+        instance.save()
+        for f in opts.many_to_many:
+            if fields and f.name not in fields:
+                continue
+            if f.name in cleaned_data:
+                setattr(instance, f.attname, cleaned_data[f.name])
+    # GOTCHA: If many-to-many data is given and commit=False, the many-to-many
+    # data will be lost. This happens because a many-to-many options cannot be
+    # set on an object until after it's saved. Maybe we should raise an
+    # exception in that case.
+    return instance
+
+def make_model_save(model, fields, fail_message):
+    "Returns the save() method for a Form."
+    def save(self, commit=True):
+        return save_instance(self, model(), fields, fail_message, commit)
+    return save
+    
+def make_instance_save(instance, fields, fail_message):
+    "Returns the save() method for a Form."
+    def save(self, commit=True):
+        return save_instance(self, instance, fields, fail_message, commit)
+    return save
+
+def form_for_model(model, form=BaseForm, fields=None, formfield_callback=lambda f: f.formfield()):
     """
     Returns a Form class for the given Django model class.
 
-    Provide 'form' if you want to use a custom BaseForm subclass.
+    Provide ``form`` if you want to use a custom BaseForm subclass.
+
+    Provide ``formfield_callback`` if you want to define different logic for
+    determining the formfield for a given database field. It's a callable that
+    takes a database Field instance and returns a form Field instance.
     """
     opts = model._meta
     field_list = []
     for f in opts.fields + opts.many_to_many:
-        formfield = f.formfield()
+        if not f.editable:
+            continue
+        if fields and not f.name in fields:
+            continue
+        formfield = formfield_callback(f)
         if formfield:
             field_list.append((f.name, formfield))
-    fields = SortedDictFromList(field_list)
-    form = form or BaseForm
-    return type(opts.object_name + 'Form', (form,), {'fields': fields, '_model': model, 'create': create})
+    base_fields = SortedDictFromList(field_list)
+    return type(opts.object_name + 'Form', (form,), 
+        {'base_fields': base_fields, '_model': model, 'save': make_model_save(model, fields, 'created')})
+
+def form_for_instance(instance, form=BaseForm, fields=None, formfield_callback=lambda f, **kwargs: f.formfield(**kwargs)):
+    """
+    Returns a Form class for the given Django model instance.
+
+    Provide ``form`` if you want to use a custom BaseForm subclass.
+
+    Provide ``formfield_callback`` if you want to define different logic for
+    determining the formfield for a given database field. It's a callable that
+    takes a database Field instance, plus **kwargs, and returns a form Field
+    instance with the given kwargs (i.e. 'initial').
+    """
+    model = instance.__class__
+    opts = model._meta
+    field_list = []
+    for f in opts.fields + opts.many_to_many:
+        if not f.editable:
+            continue
+        if fields and not f.name in fields:
+            continue
+        current_value = f.value_from_object(instance)
+        formfield = formfield_callback(f, initial=current_value)
+        if formfield:
+            field_list.append((f.name, formfield))
+    base_fields = SortedDictFromList(field_list)
+    return type(opts.object_name + 'InstanceForm', (form,),
+        {'base_fields': base_fields, '_model': model, 'save': make_instance_save(instance, fields, 'changed')})
 
 def form_for_fields(field_list):
     "Returns a Form class for the given list of Django database field instances."
-    fields = SortedDictFromList([(f.name, f.formfield()) for f in field_list])
-    return type('FormForFields', (BaseForm,), {'fields': fields})
+    fields = SortedDictFromList([(f.name, f.formfield()) for f in field_list if f.editable])
+    return type('FormForFields', (BaseForm,), {'base_fields': fields})
+
+class QuerySetIterator(object):
+    def __init__(self, queryset, empty_label, cache_choices):
+        self.queryset, self.empty_label, self.cache_choices = queryset, empty_label, cache_choices
+
+    def __iter__(self):
+        if self.empty_label is not None:
+            yield (u"", self.empty_label)
+        for obj in self.queryset:
+            yield (obj._get_pk_val(), str(obj))
+        # Clear the QuerySet cache if required.
+        if not self.cache_choices:
+            self.queryset._result_cache = None
+
+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.
+    def __init__(self, queryset, empty_label=u"---------", cache_choices=False,
+            required=True, widget=Select, label=None, initial=None, help_text=None):
+        self.queryset = queryset
+        self.empty_label = empty_label
+        self.cache_choices = cache_choices
+        # Call Field instead of ChoiceField __init__() because we don't need
+        # ChoiceField.__init__().
+        Field.__init__(self, required, widget, label, initial, help_text)
+        self.widget.choices = self.choices
+
+    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 QuerySetIterator that has not
+        # been consumed. Note that we're instantiating a new QuerySetIterator
+        # *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.
+        return QuerySetIterator(self.queryset, self.empty_label, self.cache_choices)
+
+    def _set_choices(self, value):
+        # This method is copied from ChoiceField._set_choices(). It's necessary
+        # because property() doesn't allow a subclass to overwrite only
+        # _get_choices without implementing _set_choices.
+        self._choices = self.widget.choices = list(value)
+
+    choices = property(_get_choices, _set_choices)
+
+    def clean(self, value):
+        Field.clean(self, value)
+        if value in ('', None):
+            return None
+        try:
+            value = self.queryset.model._default_manager.get(pk=value)
+        except self.queryset.model.DoesNotExist:
+            raise ValidationError(gettext(u'Select a valid choice. That choice is not one of the available choices.'))
+        return value
+
+class ModelMultipleChoiceField(ModelChoiceField):
+    "A MultipleChoiceField whose choices are a model QuerySet."
+    hidden_widget = MultipleHiddenInput
+    def __init__(self, queryset, cache_choices=False, required=True,
+            widget=SelectMultiple, label=None, initial=None, help_text=None):
+        super(ModelMultipleChoiceField, self).__init__(queryset, None, cache_choices,
+            required, widget, label, initial, help_text)
+
+    def clean(self, value):
+        if self.required and not value:
+            raise ValidationError(gettext(u'This field is required.'))
+        elif not self.required and not value:
+            return []
+        if not isinstance(value, (list, tuple)):
+            raise ValidationError(gettext(u'Enter a list of values.'))
+        final_values = []
+        for val in value:
+            try:
+                obj = self.queryset.model._default_manager.get(pk=val)
+            except self.queryset.model.DoesNotExist:
+                raise ValidationError(gettext(u'Select a valid choice. %s is not one of the available choices.') % val)
+            else:
+                final_values.append(obj)
+        return final_values
diff --git a/django/newforms/util.py b/django/newforms/util.py
index a78623a17b..891585cba2 100644
--- a/django/newforms/util.py
+++ b/django/newforms/util.py
@@ -1,21 +1,14 @@
-from django.conf import settings
+from django.utils.html import escape
+from django.utils.encoding import smart_unicode
 
-def smart_unicode(s):
-    if not isinstance(s, basestring):
-        s = unicode(str(s))
-    elif not isinstance(s, unicode):
-        s = unicode(s, settings.DEFAULT_CHARSET)
-    return s
-
-class StrAndUnicode(object):
+def flatatt(attrs):
     """
-    A class whose __str__ returns its __unicode__ as a bytestring
-    according to settings.DEFAULT_CHARSET.
-
-    Useful as a mix-in.
+    Convert a dictionary of attributes to a single string.
+    The returned string will contain a leading space followed by key="value",
+    XML-style pairs.  It is assumed that the keys do not need to be XML-escaped.
+    If the passed dictionary is empty, then return an empty string.
     """
-    def __str__(self):
-        return self.__unicode__().encode(settings.DEFAULT_CHARSET)
+    return u''.join([u' %s="%s"' % (k, escape(v)) for k, v in attrs.items()])
 
 class ErrorDict(dict):
     """
diff --git a/django/newforms/widgets.py b/django/newforms/widgets.py
index 996e353775..6ee3177a25 100644
--- a/django/newforms/widgets.py
+++ b/django/newforms/widgets.py
@@ -2,31 +2,35 @@
 HTML Widget classes
 """
 
-__all__ = (
-    'Widget', 'TextInput', 'PasswordInput', 'HiddenInput', 'FileInput',
-    'Textarea', 'CheckboxInput',
-    'Select', 'SelectMultiple', 'RadioSelect', 'CheckboxSelectMultiple',
-)
-
-from util import StrAndUnicode, smart_unicode
-from django.utils.datastructures import MultiValueDict
-from django.utils.html import escape
-from itertools import chain
-
 try:
     set # Only available in Python 2.4+
 except NameError:
     from sets import Set as set # Python 2.3 fallback
+from itertools import chain
 
-# Converts a dictionary to a single string with key="value", XML-style with
-# a leading space. Assumes keys do not need to be XML-escaped.
-flatatt = lambda attrs: u''.join([u' %s="%s"' % (k, escape(v)) for k, v in attrs.items()])
+from django.utils.datastructures import MultiValueDict
+from django.utils.html import escape
+from django.utils.translation import gettext
+from django.utils.encoding import StrAndUnicode, smart_unicode
+
+from util import flatatt
+
+__all__ = (
+    'Widget', 'TextInput', 'PasswordInput',
+    'HiddenInput', 'MultipleHiddenInput',
+    'FileInput', 'Textarea', 'CheckboxInput',
+    'Select', 'NullBooleanSelect', 'SelectMultiple', 'RadioSelect',
+    'CheckboxSelectMultiple', 'MultiWidget', 'SplitDateTimeWidget',
+)
 
 class Widget(object):
     is_hidden = False          # Determines whether this corresponds to an <input type="hidden">.
 
     def __init__(self, attrs=None):
-        self.attrs = attrs or {}
+        if attrs is not None:
+            self.attrs = attrs.copy()
+        else:
+            self.attrs = {}
 
     def render(self, name, value, attrs=None):
         """
@@ -83,14 +87,48 @@ class TextInput(Input):
 class PasswordInput(Input):
     input_type = 'password'
 
+    def __init__(self, attrs=None, render_value=True):
+        self.attrs = attrs or {}
+        self.render_value = render_value
+
+    def render(self, name, value, attrs=None):
+        if not self.render_value: value=None
+        return super(PasswordInput, self).render(name, value, attrs)
+
 class HiddenInput(Input):
     input_type = 'hidden'
     is_hidden = True
 
+class MultipleHiddenInput(HiddenInput):
+    """
+    A widget that handles <input type="hidden"> for fields that have a list
+    of values.
+    """
+    def __init__(self, attrs=None, choices=()):
+        # choices can be any iterable
+        self.attrs = attrs or {}
+        self.choices = choices
+
+    def render(self, name, value, attrs=None, choices=()):
+        if value is None: value = []
+        final_attrs = self.build_attrs(attrs, type=self.input_type, name=name)
+        return u'\n'.join([(u'<input%s />' % flatatt(dict(value=smart_unicode(v), **final_attrs))) for v in value])
+
+    def value_from_datadict(self, data, name):
+        if isinstance(data, MultiValueDict):
+            return data.getlist(name)
+        return data.get(name, None)
+
 class FileInput(Input):
     input_type = 'file'
 
 class Textarea(Widget):
+    def __init__(self, attrs=None):
+        # The 'rows' and 'cols' attributes are required for HTML correctness.
+        self.attrs = {'cols': '40', 'rows': '10'}
+        if attrs:
+            self.attrs.update(attrs)
+
     def render(self, name, value, attrs=None):
         if value is None: value = ''
         value = smart_unicode(value)
@@ -118,9 +156,11 @@ class CheckboxInput(Widget):
 
 class Select(Widget):
     def __init__(self, attrs=None, choices=()):
-        # choices can be any iterable
         self.attrs = attrs or {}
-        self.choices = choices
+        # 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)
 
     def render(self, name, value, attrs=None, choices=()):
         if value is None: value = ''
@@ -134,6 +174,25 @@ 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
@@ -162,17 +221,18 @@ class RadioInput(StrAndUnicode):
     def __init__(self, name, value, attrs, choice, index):
         self.name, self.value = name, value
         self.attrs = attrs
-        self.choice_value, self.choice_label = choice
+        self.choice_value = smart_unicode(choice[0])
+        self.choice_label = smart_unicode(choice[1])
         self.index = index
 
     def __unicode__(self):
         return u'<label>%s %s</label>' % (self.tag(), self.choice_label)
 
     def is_checked(self):
-        return self.value == smart_unicode(self.choice_value)
+        return self.value == self.choice_value
 
     def tag(self):
-        if self.attrs.has_key('id'):
+        if 'id' in self.attrs:
             self.attrs['id'] = '%s_%s' % (self.attrs['id'], self.index)
         final_attrs = dict(self.attrs, type='radio', name=self.name, value=self.choice_value)
         if self.is_checked():
@@ -202,8 +262,8 @@ class RadioSelect(Select):
         "Returns a RadioFieldRenderer instance rather than a Unicode string."
         if value is None: value = ''
         str_value = smart_unicode(value) # Normalize to string.
-        attrs = attrs or {}
-        return RadioFieldRenderer(name, str_value, attrs, list(chain(self.choices, choices)))
+        final_attrs = self.build_attrs(attrs)
+        return RadioFieldRenderer(name, str_value, final_attrs, list(chain(self.choices, choices)))
 
     def id_for_label(self, id_):
         # RadioSelect is represented by multiple <input type="radio"> fields,
@@ -218,11 +278,16 @@ class RadioSelect(Select):
 class CheckboxSelectMultiple(SelectMultiple):
     def render(self, name, value, attrs=None, choices=()):
         if value is None: value = []
+        has_id = attrs and 'id' in attrs
         final_attrs = self.build_attrs(attrs, name=name)
         output = [u'<ul>']
         str_values = set([smart_unicode(v) for v in value]) # Normalize to strings.
-        cb = CheckboxInput(final_attrs, check_test=lambda value: value in str_values)
-        for option_value, option_label in chain(self.choices, choices):
+        for i, (option_value, option_label) in enumerate(chain(self.choices, choices)):
+            # If an ID attribute was given, add a numeric index as a suffix,
+            # so that the checkboxes don't all have the same ID attribute.
+            if has_id:
+                final_attrs = dict(final_attrs, id='%s_%s' % (attrs['id'], i))
+            cb = CheckboxInput(final_attrs, check_test=lambda value: value in str_values)
             option_value = smart_unicode(option_value)
             rendered_cb = cb.render(name, option_value)
             output.append(u'<li><label>%s %s</label></li>' % (rendered_cb, escape(smart_unicode(option_label))))
@@ -235,3 +300,77 @@ class CheckboxSelectMultiple(SelectMultiple):
             id_ += '_0'
         return id_
     id_for_label = classmethod(id_for_label)
+
+class MultiWidget(Widget):
+    """
+    A widget that is composed of multiple widgets.
+
+    Its render() method takes a "decompressed" list of values, not a single
+    value. Each value in this list is rendered in the corresponding widget --
+    the first value is rendered in the first widget, the second value is
+    rendered in the second widget, etc.
+
+    Subclasses should implement decompress(), which specifies how a single
+    value should be converted to a list of values. Subclasses should not
+    have to implement clean().
+
+    Subclasses may implement format_output(), which takes the list of rendered
+    widgets and returns HTML that formats them any way you'd like.
+
+    You'll probably want to use this with MultiValueField.
+    """
+    def __init__(self, widgets, attrs=None):
+        self.widgets = [isinstance(w, type) and w() or w for w in widgets]
+        super(MultiWidget, self).__init__(attrs)
+
+    def render(self, name, value, attrs=None):
+        # value is a list of values, each corresponding to a widget
+        # in self.widgets.
+        if not isinstance(value, list):
+            value = self.decompress(value)
+        output = []
+        final_attrs = self.build_attrs(attrs)
+        id_ = final_attrs.get('id', None)
+        for i, widget in enumerate(self.widgets):
+            try:
+                widget_value = value[i]
+            except IndexError:
+                widget_value = None
+            if id_:
+                final_attrs = dict(final_attrs, id='%s_%s' % (id_, i))
+            output.append(widget.render(name + '_%s' % i, widget_value, final_attrs))
+        return self.format_output(output)
+
+    def id_for_label(self, id_):
+        # See the comment for RadioSelect.id_for_label()
+        if id_:
+            id_ += '_0'
+        return id_
+    id_for_label = classmethod(id_for_label)
+
+    def value_from_datadict(self, data, name):
+        return [widget.value_from_datadict(data, name + '_%s' % i) for i, widget in enumerate(self.widgets)]
+
+    def format_output(self, rendered_widgets):
+        return u''.join(rendered_widgets)
+
+    def decompress(self, value):
+        """
+        Returns a list of decompressed values for the given compressed value.
+        The given value can be assumed to be valid, but not necessarily
+        non-empty.
+        """
+        raise NotImplementedError('Subclasses must implement this method.')
+
+class SplitDateTimeWidget(MultiWidget):
+    """
+    A Widget that splits datetime input into two <input type="text"> boxes.
+    """
+    def __init__(self, attrs=None):
+        widgets = (TextInput(attrs=attrs), TextInput(attrs=attrs))
+        super(SplitDateTimeWidget, self).__init__(widgets, attrs)
+
+    def decompress(self, value):
+        if value:
+            return [value.date(), value.time()]
+        return [None, None]