newforms-admin: Merged to [4440]

git-svn-id: http://code.djangoproject.com/svn/django/branches/newforms-admin@4441 bcc190cf-cafb-0310-a4f2-bffc1f526a37

7 files changed, 253 insertions, 50 deletions

diff --git a/django/newforms/fields.py b/django/newforms/fields.py
index bcd30dbc92..e9e1fb7746 100644
--- a/django/newforms/fields.py
+++ b/django/newforms/fields.py
@@ -35,7 +35,7 @@ class Field(object):
     # Tracks each time a Field instance is created. Used to retain order.
     creation_counter = 0
 
-    def __init__(self, required=True, widget=None, label=None, initial=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
@@ -47,9 +47,11 @@ class Field(object):
         #         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, self.initial = required, label, initial
+        self.help_text = help_text
         widget = widget or self.widget
         if isinstance(widget, type):
             widget = widget()
@@ -85,9 +87,9 @@ class Field(object):
         return {}
 
 class CharField(Field):
-    def __init__(self, max_length=None, min_length=None, required=True, widget=None, label=None, initial=None):
+    def __init__(self, max_length=None, min_length=None, *args, **kwargs):
         self.max_length, self.min_length = max_length, min_length
-        super(CharField, self).__init__(required, widget, label, initial)
+        super(CharField, self).__init__(*args, **kwargs)
 
     def clean(self, value):
         "Validates max_length and min_length. Returns a Unicode object."
@@ -106,9 +108,9 @@ 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, initial=None):
+    def __init__(self, max_value=None, min_value=None, *args, **kwargs):
         self.max_value, self.min_value = max_value, min_value
-        super(IntegerField, self).__init__(required, widget, label, initial)
+        super(IntegerField, self).__init__(*args, **kwargs)
 
     def clean(self, value):
         """
@@ -137,8 +139,8 @@ DEFAULT_DATE_INPUT_FORMATS = (
 )
 
 class DateField(Field):
-    def __init__(self, input_formats=None, required=True, widget=None, label=None, initial=None):
-        super(DateField, self).__init__(required, widget, label, initial)
+    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):
@@ -166,8 +168,8 @@ DEFAULT_TIME_INPUT_FORMATS = (
 )
 
 class TimeField(Field):
-    def __init__(self, input_formats=None, required=True, widget=None, label=None, initial=None):
-        super(TimeField, self).__init__(required, widget, label, initial)
+    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):
@@ -200,8 +202,8 @@ DEFAULT_DATETIME_INPUT_FORMATS = (
 )
 
 class DateTimeField(Field):
-    def __init__(self, input_formats=None, required=True, widget=None, label=None, initial=None):
-        super(DateTimeField, self).__init__(required, widget, label, initial)
+    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):
@@ -224,14 +226,13 @@ 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, initial=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.
         """
-        super(RegexField, self).__init__(required, widget, label, initial)
+        super(RegexField, self).__init__(*args, **kwargs)
         if isinstance(regex, basestring):
             regex = re.compile(regex)
         self.regex = regex
@@ -263,8 +264,9 @@ 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, initial=None):
-        RegexField.__init__(self, email_re, max_length, min_length, gettext(u'Enter a valid e-mail address.'), required, widget, label, initial)
+    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://
@@ -280,9 +282,9 @@ 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,
-            initial=None, validator_user_agent=URL_VALIDATOR_USER_AGENT):
-        super(URLField, self).__init__(url_re, max_length, min_length, gettext(u'Enter a valid URL.'), required, widget, label, initial)
+    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
 
@@ -328,10 +330,8 @@ class NullBooleanField(BooleanField):
         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):
-            widget = widget()
-        super(ChoiceField, self).__init__(required, widget, label, initial)
+    def __init__(self, choices=(), required=True, widget=Select, label=None, initial=None, help_text=None):
+        super(ChoiceField, self).__init__(required, widget, label, initial, help_text)
         self.choices = choices
 
     def _get_choices(self):
@@ -362,8 +362,8 @@ class ChoiceField(Field):
 class MultipleChoiceField(ChoiceField):
     hidden_widget = MultipleHiddenInput
 
-    def __init__(self, choices=(), required=True, widget=SelectMultiple, label=None, initial=None):
-        super(MultipleChoiceField, self).__init__(choices, required, widget, label, initial)
+    def __init__(self, choices=(), required=True, widget=SelectMultiple, label=None, initial=None, help_text=None):
+        super(MultipleChoiceField, self).__init__(choices, required, widget, label, initial, help_text)
 
     def clean(self, value):
         """
@@ -390,8 +390,8 @@ class ComboField(Field):
     """
     A Field whose clean() method calls multiple Field clean() methods.
     """
-    def __init__(self, fields=(), required=True, widget=None, label=None, initial=None):
-        super(ComboField, self).__init__(required, widget, label, initial)
+    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.
@@ -425,8 +425,8 @@ class MultiValueField(Field):
 
     You'll probably want to use this with MultiWidget.
     """
-    def __init__(self, fields=(), required=True, widget=None, label=None, initial=None):
-        super(MultiValueField, self).__init__(required, widget, label, initial)
+    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.
@@ -481,9 +481,9 @@ class MultiValueField(Field):
         raise NotImplementedError('Subclasses must implement this method.')
 
 class SplitDateTimeField(MultiValueField):
-    def __init__(self, required=True, widget=None, label=None, initial=None):
+    def __init__(self, *args, **kwargs):
         fields = (DateField(), TimeField())
-        super(SplitDateTimeField, self).__init__(fields, required, widget, label, initial)
+        super(SplitDateTimeField, self).__init__(fields, *args, **kwargs)
 
     def compress(self, data_list):
         if data_list:
diff --git a/django/newforms/forms.py b/django/newforms/forms.py
index 1724a5a69f..7e29941bef 100644
--- a/django/newforms/forms.py
+++ b/django/newforms/forms.py
@@ -26,12 +26,15 @@ class SortedDictFromList(SortedDict):
         self.keyOrder = [d[0] for d in data]
         dict.__init__(self, dict(data))
 
+    def copy(self):
+        return SortedDictFromList(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'."
     def __new__(cls, name, bases, attrs):
         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)
+        attrs['base_fields'] = SortedDictFromList(fields)
         return type.__new__(cls, name, bases, attrs)
 
 class BaseForm(StrAndUnicode):
@@ -46,6 +49,12 @@ class BaseForm(StrAndUnicode):
         self.prefix = prefix
         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()
@@ -85,7 +94,7 @@ 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 = [], []
@@ -100,7 +109,11 @@ class BaseForm(StrAndUnicode):
                 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': unicode(bf)})
+                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 +128,15 @@ 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):
         """
diff --git a/django/newforms/models.py b/django/newforms/models.py
index 819e70d775..9bd6a3ff83 100644
--- a/django/newforms/models.py
+++ b/django/newforms/models.py
@@ -15,10 +15,7 @@ def model_save(self, commit=True):
     """
     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 commit:
-        obj.save()
-    return obj
+    return save_instance(self, self._model(), commit)
 
 def save_instance(form, instance, commit=True):
     """
@@ -33,12 +30,18 @@ def save_instance(form, instance, commit=True):
     if form.errors:
         raise ValueError("The %s could not be changed because the data didn't validate." % opts.object_name)
     clean_data = form.clean_data
-    for f in opts.fields + opts.many_to_many:
+    for f in opts.fields:
         if isinstance(f, models.AutoField):
             continue
         setattr(instance, f.attname, clean_data[f.name])
     if commit:
         instance.save()
+        for f in opts.many_to_many:
+            setattr(instance, f.attname, getattr(instance, f.attname).model.objects.filter(pk__in = clean_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_instance_save(instance):
@@ -64,7 +67,7 @@ def form_for_model(model, form=BaseForm, formfield_callback=lambda f: f.formfiel
         if formfield:
             field_list.append((f.name, formfield))
     fields = SortedDictFromList(field_list)
-    return type(opts.object_name + 'Form', (form,), {'fields': fields, '_model': model, 'save': model_save})
+    return type(opts.object_name + 'Form', (form,), {'base_fields': fields, '_model': model, 'save': model_save})
 
 def form_for_instance(instance, form=BaseForm, formfield_callback=lambda f, **kwargs: f.formfield(**kwargs)):
     """
@@ -87,9 +90,9 @@ def form_for_instance(instance, form=BaseForm, formfield_callback=lambda f, **kw
             field_list.append((f.name, formfield))
     fields = SortedDictFromList(field_list)
     return type(opts.object_name + 'InstanceForm', (form,),
-        {'fields': fields, '_model': model, 'save': make_instance_save(instance)})
+        {'base_fields': fields, '_model': model, 'save': make_instance_save(instance)})
 
 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})
+    return type('FormForFields', (BaseForm,), {'base_fields': fields})
diff --git a/django/newforms/widgets.py b/django/newforms/widgets.py
index c71810465e..585e12cc18 100644
--- a/django/newforms/widgets.py
+++ b/django/newforms/widgets.py
@@ -136,9 +136,11 @@ 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 = ''
@@ -256,11 +258,16 @@ class RadioSelect(Select):
 class CheckboxSelectMultiple(SelectMultiple):
     def render(self, name, value, attrs=None, choices=()):
         if value is None: value = []
+        has_id = attrs and attrs.has_key('id')
         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))))
diff --git a/docs/newforms.txt b/docs/newforms.txt
index aeed33752a..063f686ed5 100644
--- a/docs/newforms.txt
+++ b/docs/newforms.txt
@@ -739,6 +739,38 @@ validation if a particular field's value is not given. ``initial`` values are
 The ``widget`` argument lets you specify a ``Widget`` class to use when
 rendering this ``Field``. See _`Widgets` below for more information.
 
+``help_text``
+~~~~~~~~~~~~~
+
+The ``help_text`` argument lets you specify descriptive text for this
+``Field``. If you provide ``help_text``, it will be displayed next to the
+``Field`` when the ``Field`` is rendered in a ``Form``.
+
+Here's a full example ``Form`` that implements ``help_text`` for two of its
+fields. We've specified ``auto_id=False`` to simplify the output::
+
+    >>> class HelpTextContactForm(forms.Form):
+    ...     subject = forms.CharField(max_length=100, help_text='100 characters max.')
+    ...     message = forms.CharField()
+    ...     sender = forms.EmailField(help_text='A valid e-mail address, please.')
+    ...     cc_myself = forms.BooleanField()
+    >>> f = HelpTextContactForm(auto_id=False)
+    >>> print f.as_table()
+    <tr><th>Subject:</th><td><input type="text" name="subject" maxlength="100" /><br />100 characters max.</td></tr>
+    <tr><th>Message:</th><td><input type="text" name="message" /></td></tr>
+    <tr><th>Sender:</th><td><input type="text" name="sender" /><br />A valid e-mail address, please.</td></tr>
+    <tr><th>Cc myself:</th><td><input type="checkbox" name="cc_myself" /></td></tr>
+    >>> print f.as_ul()
+    <li>Subject: <input type="text" name="subject" maxlength="100" /> 100 characters max.</li>
+    <li>Message: <input type="text" name="message" /></li>
+    <li>Sender: <input type="text" name="sender" /> A valid e-mail address, please.</li>
+    <li>Cc myself: <input type="checkbox" name="cc_myself" /></li>
+    >>> print f.as_p()
+    <p>Subject: <input type="text" name="subject" maxlength="100" /> 100 characters max.</p>
+    <p>Message: <input type="text" name="message" /></p>
+    <p>Sender: <input type="text" name="sender" /> A valid e-mail address, please.</p>
+    <p>Cc myself: <input type="checkbox" name="cc_myself" /></p>
+
 Dynamic initial values
 ----------------------
 
diff --git a/tests/modeltests/model_forms/models.py b/tests/modeltests/model_forms/models.py
index 620565721c..81a7ec2abf 100644
--- a/tests/modeltests/model_forms/models.py
+++ b/tests/modeltests/model_forms/models.py
@@ -224,6 +224,47 @@ Add some categories and test the many-to-many form output.
 <option value="3">Third test</option>
 </select></li>
 
+>>> f = TestArticleForm({'headline': u'New headline', 'pub_date': u'1988-01-04',
+...     'writer': u'1', 'article': u'Hello.', 'categories': [u'1', u'2']})
+>>> new_art = f.save()
+>>> new_art.id
+1
+>>> new_art = Article.objects.get(id=1)
+>>> new_art.categories.all()
+[<Category: Entertainment>, <Category: It's a test>]
+
+Now, submit form data with no categories. This deletes the existing categories.
+>>> f = TestArticleForm({'headline': u'New headline', 'pub_date': u'1988-01-04',
+...     'writer': u'1', 'article': u'Hello.'})
+>>> new_art = f.save()
+>>> new_art.id
+1
+>>> new_art = Article.objects.get(id=1)
+>>> new_art.categories.all()
+[]
+
+Create a new article, with categories, via the form.
+>>> ArticleForm = form_for_model(Article)
+>>> f = ArticleForm({'headline': u'The walrus was Paul', 'pub_date': u'1967-11-01',
+...     'writer': u'1', 'article': u'Test.', 'categories': [u'1', u'2']})
+>>> new_art = f.save()
+>>> new_art.id
+2
+>>> new_art = Article.objects.get(id=2)
+>>> new_art.categories.all()
+[<Category: Entertainment>, <Category: It's a test>]
+
+Create a new article, with no categories, via the form.
+>>> ArticleForm = form_for_model(Article)
+>>> f = ArticleForm({'headline': u'The walrus was Paul', 'pub_date': u'1967-11-01',
+...     'writer': u'1', 'article': u'Test.'})
+>>> new_art = f.save()
+>>> new_art.id
+3
+>>> new_art = Article.objects.get(id=3)
+>>> new_art.categories.all()
+[]
+
 Here, we define a custom Form. Because it happens to have the same fields as
 the Category model, we can use save_instance() to apply its changes to an
 existing Category instance.
diff --git a/tests/regressiontests/forms/tests.py b/tests/regressiontests/forms/tests.py
index 95e8b59c01..20a1937f56 100644
--- a/tests/regressiontests/forms/tests.py
+++ b/tests/regressiontests/forms/tests.py
@@ -336,6 +336,26 @@ 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>'
 
+If choices is passed to the constructor and is a generator, it can be iterated
+over multiple times without getting consumed:
+>>> w = Select(choices=get_choices())
+>>> print w.render('num', 2)
+<select name="num">
+<option value="0">0</option>
+<option value="1">1</option>
+<option value="2" selected="selected">2</option>
+<option value="3">3</option>
+<option value="4">4</option>
+</select>
+>>> print w.render('num', 3)
+<select name="num">
+<option value="0">0</option>
+<option value="1">1</option>
+<option value="2">2</option>
+<option value="3" selected="selected">3</option>
+<option value="4">4</option>
+</select>
+
 # NullBooleanSelect Widget ####################################################
 
 >>> w = NullBooleanSelect()
@@ -2129,6 +2149,16 @@ MultipleChoiceField can also be used with the CheckboxSelectMultiple widget.
 <li><label><input checked="checked" type="checkbox" name="composers" value="P" /> Paul McCartney</label></li>
 </ul>
 
+Regarding auto_id, CheckboxSelectMultiple is a special case. Each checkbox
+gets a distinct ID, formed by appending an underscore plus the checkbox's
+zero-based index.
+>>> f = SongForm(auto_id='%s_id')
+>>> print f['composers']
+<ul>
+<li><label><input type="checkbox" name="composers" value="J" id="composers_id_0" /> John Lennon</label></li>
+<li><label><input type="checkbox" name="composers" value="P" id="composers_id_1" /> Paul McCartney</label></li>
+</ul>
+
 Data for a MultipleChoiceField should be a list. QueryDict and MultiValueDict
 conveniently work with this.
 >>> data = {'name': 'Yesterday', 'composers': ['J', 'P']}
@@ -2247,6 +2277,8 @@ Form.clean() is required to return a dictionary of all clean data.
 >>> f.clean_data
 {'username': u'adrian', 'password1': u'foo', 'password2': u'foo'}
 
+# Dynamic construction ########################################################
+
 It's possible to construct a Form dynamically by adding to the self.fields
 dictionary in __init__(). Don't forget to call Form.__init__() within the
 subclass' __init__().
@@ -2262,6 +2294,46 @@ subclass' __init__().
 <tr><th>Last name:</th><td><input type="text" name="last_name" /></td></tr>
 <tr><th>Birthday:</th><td><input type="text" name="birthday" /></td></tr>
 
+Instances of a dynamic Form do not persist fields from one Form instance to
+the next.
+>>> class MyForm(Form):
+...     def __init__(self, data=None, auto_id=False, field_list=[]):
+...         Form.__init__(self, data, auto_id)
+...         for field in field_list:
+...             self.fields[field[0]] = field[1]
+>>> field_list = [('field1', CharField()), ('field2', CharField())]
+>>> my_form = MyForm(field_list=field_list)
+>>> print my_form
+<tr><th>Field1:</th><td><input type="text" name="field1" /></td></tr>
+<tr><th>Field2:</th><td><input type="text" name="field2" /></td></tr>
+>>> field_list = [('field3', CharField()), ('field4', CharField())]
+>>> my_form = MyForm(field_list=field_list)
+>>> print my_form
+<tr><th>Field3:</th><td><input type="text" name="field3" /></td></tr>
+<tr><th>Field4:</th><td><input type="text" name="field4" /></td></tr>
+
+>>> class MyForm(Form):
+...     default_field_1 = CharField()
+...     default_field_2 = CharField()
+...     def __init__(self, data=None, auto_id=False, field_list=[]):
+...         Form.__init__(self, data, auto_id)
+...         for field in field_list:
+...             self.fields[field[0]] = field[1]
+>>> field_list = [('field1', CharField()), ('field2', CharField())]
+>>> my_form = MyForm(field_list=field_list)
+>>> print my_form
+<tr><th>Default field 1:</th><td><input type="text" name="default_field_1" /></td></tr>
+<tr><th>Default field 2:</th><td><input type="text" name="default_field_2" /></td></tr>
+<tr><th>Field1:</th><td><input type="text" name="field1" /></td></tr>
+<tr><th>Field2:</th><td><input type="text" name="field2" /></td></tr>
+>>> field_list = [('field3', CharField()), ('field4', CharField())]
+>>> my_form = MyForm(field_list=field_list)
+>>> print my_form
+<tr><th>Default field 1:</th><td><input type="text" name="default_field_1" /></td></tr>
+<tr><th>Default field 2:</th><td><input type="text" name="default_field_2" /></td></tr>
+<tr><th>Field3:</th><td><input type="text" name="field3" /></td></tr>
+<tr><th>Field4:</th><td><input type="text" name="field4" /></td></tr>
+
 HiddenInput widgets are displayed differently in the as_table(), as_ul()
 and as_p() output of a Form -- their verbose names are not displayed, and a
 separate row is not displayed. They're displayed in the last row of the
@@ -2538,6 +2610,41 @@ then the latter will get precedence.
 <li>Username: <input type="text" name="username" value="babik" maxlength="10" /></li>
 <li>Password: <input type="password" name="password" /></li>
 
+# Help text ###################################################################
+
+You can specify descriptive text for a field by using the 'help_text' argument
+to a Field class. This help text is displayed when a Form is rendered.
+>>> class UserRegistration(Form):
+...    username = CharField(max_length=10, help_text='e.g., user@example.com')
+...    password = CharField(widget=PasswordInput, help_text='Choose wisely.')
+>>> p = UserRegistration(auto_id=False)
+>>> print p.as_ul()
+<li>Username: <input type="text" name="username" maxlength="10" /> e.g., user@example.com</li>
+<li>Password: <input type="password" name="password" /> Choose wisely.</li>
+>>> print p.as_p()
+<p>Username: <input type="text" name="username" maxlength="10" /> e.g., user@example.com</p>
+<p>Password: <input type="password" name="password" /> Choose wisely.</p>
+>>> print p.as_table()
+<tr><th>Username:</th><td><input type="text" name="username" maxlength="10" /><br />e.g., user@example.com</td></tr>
+<tr><th>Password:</th><td><input type="password" name="password" /><br />Choose wisely.</td></tr>
+
+The help text is displayed whether or not data is provided for the form.
+>>> p = UserRegistration({'username': u'foo'}, auto_id=False)
+>>> print p.as_ul()
+<li>Username: <input type="text" name="username" value="foo" maxlength="10" /> e.g., user@example.com</li>
+<li><ul class="errorlist"><li>This field is required.</li></ul>Password: <input type="password" name="password" /> Choose wisely.</li>
+
+help_text is not displayed for hidden fields. It can be used for documentation
+purposes, though.
+>>> class UserRegistration(Form):
+...    username = CharField(max_length=10, help_text='e.g., user@example.com')
+...    password = CharField(widget=PasswordInput)
+...    next = CharField(widget=HiddenInput, initial='/', help_text='Redirect destination')
+>>> p = UserRegistration(auto_id=False)
+>>> print p.as_ul()
+<li>Username: <input type="text" name="username" maxlength="10" /> e.g., user@example.com</li>
+<li>Password: <input type="password" name="password" /><input type="hidden" name="next" value="/" /></li>
+
 # Forms with prefixes #########################################################
 
 Sometimes it's necessary to have multiple forms display on the same HTML page,