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

1 files changed, 1380 insertions, 35 deletions

diff --git a/docs/newforms.txt b/docs/newforms.txt
index c4986eb45e..1511791a7d 100644
--- a/docs/newforms.txt
+++ b/docs/newforms.txt
@@ -2,34 +2,37 @@
 The newforms library
 ====================
 
-``django.newforms`` is a new replacement for ``django.forms``, the old Django
-form/manipulator/validation framework. This document explains how to use this
-new form library.
+``django.newforms`` is Django's fantastic new form-handling library. It's a
+replacement for ``django.forms``, the old form/manipulator/validation
+framework. This document explains how to use this new library.
 
 Migration plan
 ==============
 
-``django.newforms`` currently is only available in the Django development version
--- i.e., it's not available in the Django 0.95 release. For the next Django
-release, our plan is to do the following:
+``django.newforms`` is new in Django's 0.96 release, but, as it won't be new
+forever, we plan to rename it to ``django.forms`` in the future. The current
+``django.forms`` package will be available as ``django.oldforms`` until Django
+1.0, when we plan to remove it for good.
 
-    * As of revision [4208], we've copied the current ``django.forms`` to
-      ``django.oldforms``. This allows you to upgrade your code *now* rather
-      than waiting for the backwards-incompatible change and rushing to fix
-      your code after the fact. Just change your import statements like this::
+That has direct repercussions on the forward compatibility of your code. Please
+read the following migration plan and code accordingly:
+
+    * The old forms framework (the current ``django.forms``) has been copied to
+      ``django.oldforms``. Thus, you can start upgrading your code *now*,
+      rather than waiting for the future backwards-incompatible change, by
+      changing your import statements like this::
 
           from django import forms             # old
           from django import oldforms as forms # new
 
-    * At an undecided future date, we will move the current ``django.newforms``
-      to ``django.forms``. This will be a backwards-incompatible change, and 
-      anybody who is still using the old version of ``django.forms`` at that
-      time will need to change their import statements, as described in the
-      previous bullet.
+    * In the next Django release (0.97), we will move the current
+      ``django.newforms`` to ``django.forms``. This will be a
+      backwards-incompatible change, and anybody who is still using the old
+      version of ``django.forms`` at that time will need to change their import
+      statements, as described in the previous bullet.
 
     * We will remove ``django.oldforms`` in the release *after* the next Django
-      release -- the release that comes after the release in which we're
-      creating the new ``django.forms``.
+      release -- either 0.98 or 1.0, whichever comes first.
 
 With this in mind, we recommend you use the following import statement when
 using ``django.newforms``::
@@ -51,9 +54,10 @@ too messy. The choice is yours.
 Overview
 ========
 
-As the ``django.forms`` ("manipulators") system before it, ``django.newforms``
-is intended to handle HTML form display, validation and redisplay. It's what
-you use if you want to perform server-side validation for an HTML form.
+As with the ``django.forms`` ("manipulators") system before it,
+``django.newforms`` is intended to handle HTML form display, data processing
+(validation) and redisplay. It's what you use if you want to perform
+server-side validation for an HTML form.
 
 For example, if your Web site has a contact form that visitors can use to
 send you e-mail, you'd use this library to implement the display of the HTML
@@ -72,6 +76,12 @@ The library deals with these concepts:
     * **Form** -- A collection of fields that knows how to validate itself and
       display itself as HTML.
 
+The library is decoupled from the other Django components, such as the database
+layer, views and templates. It relies only on Django settings, a couple of
+``django.utils`` helper functions and Django's internationalization hooks (but
+you're not required to be using internationalization features to use this
+library).
+
 Form objects
 ============
 
@@ -79,8 +89,8 @@ The primary way of using the ``newforms`` library is to create a form object.
 Do this by subclassing ``django.newforms.Form`` and specifying the form's
 fields, in a declarative style that you'll be familiar with if you've used
 Django database models. In this section, we'll iteratively develop a form
-object that you might to implement "contact me" functionality on your personal
-Web site.
+object that you might use to implement "contact me" functionality on your
+personal Web site.
 
 Start with this basic ``Form`` subclass, which we'll call ``ContactForm``::
 
@@ -97,11 +107,224 @@ fields: ``subject``, ``message``, ``sender`` and ``cc_myself``. We'll explain
 the different types of fields -- e.g., ``CharField`` and ``EmailField`` --
 shortly.
 
+Creating ``Form`` instances
+---------------------------
+
+A ``Form`` instance is either **bound** or **unbound** to a set of data.
+
+    * If it's **bound** to a set of data, it's capable of validating that data
+      and rendering the form as HTML with the data displayed in the HTML.
+
+    * If it's **unbound**, it cannot do validation (because there's no data to
+      validate!), but it can still render the blank form as HTML.
+
+To create an unbound ``Form`` instance, simply instantiate the class::
+
+    >>> f = ContactForm()
+
+To bind data to a form, pass the data as a dictionary as the first parameter to
+your ``Form`` class constructor::
+
+    >>> data = {'subject': 'hello',
+    ...         'message': 'Hi there',
+    ...         'sender': 'foo@example.com',
+    ...         'cc_myself': True}
+    >>> f = ContactForm(data)
+
+In this dictionary, the keys are the field names, which correspond to the
+attributes in your ``Form`` class. The values are the data you're trying
+to validate. These will usually be strings, but there's no requirement that
+they be strings; the type of data you pass depends on the ``Field``, as we'll
+see in a moment.
+
+If you need to distinguish between bound and unbound form instances at runtime,
+check the value of the form's ``is_bound`` attribute::
+
+    >>> f = ContactForm()
+    >>> f.is_bound
+    False
+    >>> f = ContactForm({'subject': 'hello'})
+    >>> f.is_bound
+    True
+
+Note that passing an empty dictionary creates a *bound* form with empty data::
+
+    >>> f = ContactForm({})
+    >>> f.is_bound
+    True
+
+If you have a bound ``Form`` instance and want to change the data somehow, or
+if you want to bind an unbound ``Form`` instance to some data, create another
+``Form`` instance. There is no way to change data in a ``Form`` instance. Once
+a ``Form`` instance has been created, you should consider its data immutable,
+whether it has data or not.
+
+Using forms to validate data
+----------------------------
+
+The primary task of a ``Form`` object is to validate data. With a bound
+``Form`` instance, call the ``is_valid()`` method to run validation and return
+a boolean designating whether the data was valid::
+
+    >>> data = {'subject': 'hello',
+    ...         'message': 'Hi there',
+    ...         'sender': 'foo@example.com',
+    ...         'cc_myself': True}
+    >>> f = ContactForm(data)
+    >>> f.is_valid()
+    True
+
+Let's try with some invalid data. In this case, ``subject`` is blank (an error,
+because all fields are required by default) and ``sender`` is not a valid
+e-mail address::
+
+    >>> data = {'subject': '',
+    ...         'message': 'Hi there',
+    ...         'sender': 'invalid e-mail address',
+    ...         'cc_myself': True}
+    >>> f = ContactForm(data)
+    >>> f.is_valid()
+    False
+
+Access the ``errors`` attribute to get a dictionary of error messages::
+
+    >>> f.errors
+    {'sender': [u'Enter a valid e-mail address.'], 'subject': [u'This field is required.']}
+
+In this dictionary, the keys are the field names, and the values are lists of
+Unicode strings representing the error messages. The error messages are stored
+in lists because a field can have multiple error messages.
+
+You can access ``errors`` without having to call ``is_valid()`` first. The
+form's data will be validated the first time either you call ``is_valid()`` or
+access ``errors``.
+
+The validation routines will only get called once, regardless of how many times
+you access ``errors`` or call ``is_valid()``. This means that if validation has
+side effects, those side effects will only be triggered once.
+
+Behavior of unbound forms
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+It's meaningless to validate a form with no data, but, for the record, here's
+what happens with unbound forms::
+
+    >>> f = ContactForm()
+    >>> f.is_valid()
+    False
+    >>> f.errors
+    {}
+
+Accessing "clean" data
+----------------------
+
+Each ``Field`` in a ``Form`` class is responsible not only for validating data,
+but also for "cleaning" it -- normalizing it to a consistent format. This is a
+nice feature, because it allows data for a particular field to be input in
+a variety of ways, always resulting in consistent output.
+
+For example, ``DateField`` normalizes input into a Python ``datetime.date``
+object. Regardless of whether you pass it a string in the format
+``'1994-07-15'``, a ``datetime.date`` object or a number of other formats,
+``DateField`` will always normalize it to a ``datetime.date`` object as long as
+it's valid.
+
+Once you've created a ``Form`` instance with a set of data and validated it,
+you can access the clean data via the ``cleaned_data`` attribute of the ``Form``
+object::
+
+    >>> data = {'subject': 'hello',
+    ...         'message': 'Hi there',
+    ...         'sender': 'foo@example.com',
+    ...         'cc_myself': True}
+    >>> f = ContactForm(data)
+    >>> f.is_valid()
+    True
+    >>> f.cleaned_data
+    {'cc_myself': True, 'message': u'Hi there', 'sender': u'foo@example.com', 'subject': u'hello'}
+
+Note that any text-based field -- such as ``CharField`` or ``EmailField`` --
+always cleans the input into a Unicode string. We'll cover the encoding
+implications later in this document.
+
+If your data does *not* validate, your ``Form`` instance will not have a
+``cleaned_data`` attribute::
+
+    >>> data = {'subject': '',
+    ...         'message': 'Hi there',
+    ...         'sender': 'invalid e-mail address',
+    ...         'cc_myself': True}
+    >>> f = ContactForm(data)
+    >>> f.is_valid()
+    False
+    >>> f.cleaned_data
+    Traceback (most recent call last):
+    ...
+    AttributeError: 'ContactForm' object has no attribute 'cleaned_data'
+
+``cleaned_data`` will always *only* contain a key for fields defined in the
+``Form``, even if you pass extra data when you define the ``Form``. In this
+example, we pass a bunch of extra fields to the ``ContactForm`` constructor,
+but ``cleaned_data`` contains only the form's fields::
+
+    >>> data = {'subject': 'hello',
+    ...         'message': 'Hi there',
+    ...         'sender': 'foo@example.com',
+    ...         'cc_myself': True,
+    ...         'extra_field_1': 'foo',
+    ...         'extra_field_2': 'bar',
+    ...         'extra_field_3': 'baz'}
+    >>> f = ContactForm(data)
+    >>> f.is_valid()
+    True
+    >>> f.cleaned_data # Doesn't contain extra_field_1, etc.
+    {'cc_myself': True, 'message': u'Hi there', 'sender': u'foo@example.com', 'subject': u'hello'}
+
+``cleaned_data`` will include a key and value for *all* fields defined in the
+``Form``, even if the data didn't include a value for fields that are not
+required. In this example, the data dictionary doesn't include a value for the
+``nick_name`` field, but ``cleaned_data`` includes it, with an empty value::
+
+    >>> class OptionalPersonForm(Form):
+    ...     first_name = CharField()
+    ...     last_name = CharField()
+    ...     nick_name = CharField(required=False)
+    >>> data = {'first_name': u'John', 'last_name': u'Lennon'}
+    >>> f = OptionalPersonForm(data)
+    >>> f.is_valid()
+    True
+    >>> f.cleaned_data
+    {'nick_name': u'', 'first_name': u'John', 'last_name': u'Lennon'}
+
+In this above example, the ``cleaned_data`` value for ``nick_name`` is set to an
+empty string, because ``nick_name`` is ``CharField``, and ``CharField``\s treat
+empty values as an empty string. Each field type knows what its "blank" value
+is -- e.g., for ``DateField``, it's ``None`` instead of the empty string. For
+full details on each field's behavior in this case, see the "Empty value" note
+for each field in the "Built-in ``Field`` classes" section below.
+
+You can write code to perform validation for particular form fields (based on
+their name) or for the form as a whole (considering combinations of various
+fields). More information about this is in the `Custom form and field
+validation`_ section, below.
+
+Behavior of unbound forms
+~~~~~~~~~~~~~~~~~~~~~~~~~
+
+It's meaningless to request "cleaned" data in a form with no data, but, for the
+record, here's what happens with unbound forms::
+
+    >>> f = ContactForm()
+    >>> f.cleaned_data
+    Traceback (most recent call last):
+    ...
+    AttributeError: 'ContactForm' object has no attribute 'cleaned_data'
+
 Outputting forms as HTML
 ------------------------
 
-The first thing we can do with this is output it as HTML. To do so, instantiate
-it and ``print`` it::
+The second task of a ``Form`` object is to render itself as HTML. To do so,
+simply ``print`` it::
 
     >>> f = ContactForm()
     >>> print f
@@ -110,6 +333,23 @@ it and ``print`` it::
     <tr><th><label for="id_sender">Sender:</label></th><td><input type="text" name="sender" id="id_sender" /></td></tr>
     <tr><th><label for="id_cc_myself">Cc myself:</label></th><td><input type="checkbox" name="cc_myself" id="id_cc_myself" /></td></tr>
 
+If the form is bound to data, the HTML output will include that data
+appropriately. For example, if a field is represented by an
+``<input type="text">``, the data will be in the ``value`` attribute. If a
+field is represented by an ``<input type="checkbox">``, then that HTML will
+include ``checked="checked"`` if appropriate::
+
+    >>> data = {'subject': 'hello',
+    ...         'message': 'Hi there',
+    ...         'sender': 'foo@example.com',
+    ...         'cc_myself': True}
+    >>> f = ContactForm(data)
+    >>> print f
+    <tr><th><label for="id_subject">Subject:</label></th><td><input id="id_subject" type="text" name="subject" maxlength="100" value="hello" /></td></tr>
+    <tr><th><label for="id_message">Message:</label></th><td><input type="text" name="message" id="id_message" value="Hi there" /></td></tr>
+    <tr><th><label for="id_sender">Sender:</label></th><td><input type="text" name="sender" id="id_sender" value="foo@example.com" /></td></tr>
+    <tr><th><label for="id_cc_myself">Cc myself:</label></th><td><input type="checkbox" name="cc_myself" id="id_cc_myself" checked="checked" /></td></tr>
+
 This default output is a two-column HTML table, with a ``<tr>`` for each field.
 Notice the following:
 
@@ -121,13 +361,13 @@ Notice the following:
       ``EmailField`` are represented by an ``<input type="text">``.
       ``BooleanField`` is represented by an ``<input type="checkbox">``. Note
       these are merely sensible defaults; you can specify which HTML to use for
-      a given field by using ``widgets``, which we'll explain shortly.
+      a given field by using widgets, which we'll explain shortly.
 
     * The HTML ``name`` for each tag is taken directly from its attribute name
       in the ``ContactForm`` class.
 
     * The text label for each field -- e.g. ``'Subject:'``, ``'Message:'`` and
-      ``'CC myself:'`` is generated from the field name by converting all
+      ``'Cc myself:'`` is generated from the field name by converting all
       underscores to spaces and upper-casing the first letter. Again, note
       these are merely sensible defaults; you can also specify labels manually.
 
@@ -248,7 +488,7 @@ field::
 If ``auto_id`` is set to a string containing the format character ``'%s'``,
 then the form output will include ``<label>`` tags, and will generate ``id``
 attributes based on the format string. For example, for a format string
-``'field_%s'``, a field named ``subject`` will get the ``id``
+``'field_%s'``, a field named ``subject`` will get the ``id`` value
 ``'field_subject'``. Continuing our example::
 
     >>> f = ContactForm(auto_id='id_for_%s')
@@ -282,6 +522,1117 @@ example, in the ``ContactForm`` example, the fields are defined in the order
 ``subject``, ``message``, ``sender``, ``cc_myself``. To reorder the HTML
 output, just change the order in which those fields are listed in the class.
 
+How errors are displayed
+~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you render a bound ``Form`` object, the act of rendering will automatically
+run the form's validation if it hasn't already happened, and the HTML output
+will include the validation errors as a ``<ul class="errorlist">`` near the
+field. The particular positioning of the error messages depends on the output
+method you're using::
+
+    >>> data = {'subject': '',
+    ...         'message': 'Hi there',
+    ...         'sender': 'invalid e-mail address',
+    ...         'cc_myself': True}
+    >>> f = ContactForm(data, auto_id=False)
+    >>> print f.as_table()
+    <tr><th>Subject:</th><td><ul class="errorlist"><li>This field is required.</li></ul><input type="text" name="subject" maxlength="100" /></td></tr>
+    <tr><th>Message:</th><td><input type="text" name="message" value="Hi there" /></td></tr>
+    <tr><th>Sender:</th><td><ul class="errorlist"><li>Enter a valid e-mail address.</li></ul><input type="text" name="sender" value="invalid e-mail address" /></td></tr>
+    <tr><th>Cc myself:</th><td><input checked="checked" type="checkbox" name="cc_myself" /></td></tr>
+    >>> print f.as_ul()
+    <li><ul class="errorlist"><li>This field is required.</li></ul>Subject: <input type="text" name="subject" maxlength="100" /></li>
+    <li>Message: <input type="text" name="message" value="Hi there" /></li>
+    <li><ul class="errorlist"><li>Enter a valid e-mail address.</li></ul>Sender: <input type="text" name="sender" value="invalid e-mail address" /></li>
+    <li>Cc myself: <input checked="checked" type="checkbox" name="cc_myself" /></li>
+    >>> print f.as_p()
+    <p><ul class="errorlist"><li>This field is required.</li></ul></p>
+    <p>Subject: <input type="text" name="subject" maxlength="100" /></p>
+    <p>Message: <input type="text" name="message" value="Hi there" /></p>
+    <p><ul class="errorlist"><li>Enter a valid e-mail address.</li></ul></p>
+    <p>Sender: <input type="text" name="sender" value="invalid e-mail address" /></p>
+    <p>Cc myself: <input checked="checked" type="checkbox" name="cc_myself" /></p>
+
+More granular output
+~~~~~~~~~~~~~~~~~~~~
+
+The ``as_p()``, ``as_ul()`` and ``as_table()`` methods are simply shortcuts for
+lazy developers -- they're not the only way a form object can be displayed.
+
+To display the HTML for a single field in your form, use dictionary lookup
+syntax using the field's name as the key, and print the resulting object::
+
+    >>> f = ContactForm()
+    >>> print f['subject']
+    <input id="id_subject" type="text" name="subject" maxlength="100" />
+    >>> print f['message']
+    <input type="text" name="message" id="id_message" />
+    >>> print f['sender']
+    <input type="text" name="sender" id="id_sender" />
+    >>> print f['cc_myself']
+    <input type="checkbox" name="cc_myself" id="id_cc_myself" />
+
+Call ``str()`` or ``unicode()`` on the field to get its rendered HTML as a
+string or Unicode object, respectively::
+
+    >>> str(f['subject'])
+    '<input id="id_subject" type="text" name="subject" maxlength="100" />'
+    >>> unicode(f['subject'])
+    u'<input id="id_subject" type="text" name="subject" maxlength="100" />'
+
+The field-specific output honors the form object's ``auto_id`` setting::
+
+    >>> f = ContactForm(auto_id=False)
+    >>> print f['message']
+    <input type="text" name="message" />
+    >>> f = ContactForm(auto_id='id_%s')
+    >>> print f['message']
+    <input type="text" name="message" id="id_message" />
+
+For a field's list of errors, access the field's ``errors`` attribute. This
+is a list-like object that is displayed as an HTML ``<ul class="errorlist">``
+when printed::
+
+    >>> data = {'subject': 'hi', 'message': '', 'sender': '', 'cc_myself': ''}
+    >>> f = ContactForm(data, auto_id=False)
+    >>> print f['message']
+    <input type="text" name="message" />
+    >>> f['message'].errors
+    [u'This field is required.']
+    >>> print f['message'].errors
+    <ul class="errorlist"><li>This field is required.</li></ul>
+    >>> f['subject'].errors
+    []
+    >>> print f['subject'].errors
+
+    >>> str(f['subject'].errors)
+    ''
+
+Using forms in views and templates
+----------------------------------
+
+Let's put this all together and use the ``ContactForm`` example in a Django
+view and template.
+
+Simple view example
+~~~~~~~~~~~~~~~~~~~
+
+This example view displays the contact form by default and validates/processes
+it if accessed via a POST request::
+
+    def contact(request):
+        if request.method == 'POST':
+            form = ContactForm(request.POST)
+            if form.is_valid():
+                # Do form processing here...
+                return HttpResponseRedirect('/url/on_success/')
+        else:
+            form = ContactForm()
+        return render_to_response('contact.html', {'form': form})
+
+Simple template example
+~~~~~~~~~~~~~~~~~~~~~~~
+
+The template in the above view example, ``contact.html``, is responsible for
+displaying the form as HTML. To do this, we can use the techniques outlined in
+the "Outputting forms as HTML" section above.
+
+The simplest way to display a form's HTML is to use the variable on its own,
+like this::
+
+    <form method="post">
+    <table>{{ form }}</table>
+    <input type="submit" />
+    </form>
+
+The above template code will display the form as an HTML table, using the
+``form.as_table()`` method explained previously. This works because Django's
+template system displays an object's ``__str__()`` value, and the ``Form``
+class' ``__str__()`` method calls its ``as_table()`` method.
+
+The following is equivalent but a bit more explicit::
+
+    <form method="post">
+    <table>{{ form.as_table }}</table>
+    <input type="submit" />
+    </form>
+
+``form.as_ul`` and ``form.as_p`` are also available, as you may expect.
+
+Note that in the above two examples, we included the ``<form>``, ``<table>``
+``<input type="submit" />``, ``</table>`` and ``</form>`` tags. The form
+convenience methods (``as_table()``, ``as_ul()`` and ``as_p()``) do not include
+that HTML.
+
+Complex template output
+~~~~~~~~~~~~~~~~~~~~~~~
+
+As we've stressed several times, the ``as_table()``, ``as_ul()`` and ``as_p()``
+methods are just shortcuts for the common case. You can also work with the
+individual fields for complete template control over the form's design.
+
+The easiest way is to iterate over the form's fields, with
+``{% for field in form %}``. For example::
+
+    <form method="post">
+    <dl>
+    {% for field in form %}
+        <dt>{{ field.label }}</dt>
+        <dd>{{ field }}</dd>
+        {% if field.help_text %}<dd>{{ field.help_text }}</dd>{% endif %}
+        {% if field.errors %}<dd class="myerrors">{{ field.errors }}</dd>{% endif %}
+    {% endfor %}
+    </dl>
+    <input type="submit" />
+    </form>
+
+This iteration technique is useful if you want to apply the same HTML
+formatting to each field, or if you don't know the names of the form fields
+ahead of time. Note that the fields will be iterated over in the order in which
+they're defined in the ``Form`` class.
+
+Alternatively, you can arrange the form's fields explicitly, by name. Do that
+by accessing ``{{ form.fieldname }}``, where ``fieldname`` is the field's name.
+For example::
+
+    <form method="post">
+    <ul class="myformclass">
+        <li>{{ form.sender.label }} {{ form.sender }}</li>
+        <li class="helptext">{{ form.sender.help_text }}</li>
+        {% if form.sender.errors %}<ul class="errorlist">{{ form.sender.errors }}</ul>{% endif %}
+
+        <li>{{ form.subject.label }} {{ form.subject }}</li>
+        <li class="helptext">{{ form.subject.help_text }}</li>
+        {% if form.subject.errors %}<ul class="errorlist">{{ form.subject.errors }}</ul>{% endif %}
+
+        ...
+    </ul>
+    </form>
+
+Subclassing forms
+-----------------
+
+If you have multiple ``Form`` classes that share fields, you can use
+subclassing to remove redundancy.
+
+When you subclass a custom ``Form`` class, the resulting subclass will
+include all fields of the parent class(es), followed by the fields you define
+in the subclass.
+
+In this example, ``ContactFormWithPriority`` contains all the fields from
+``ContactForm``, plus an additional field, ``priority``. The ``ContactForm``
+fields are ordered first::
+
+    >>> class ContactFormWithPriority(ContactForm):
+    ...     priority = forms.CharField()
+    >>> f = ContactFormWithPriority(auto_id=False)
+    >>> print f.as_ul()
+    <li>Subject: <input type="text" name="subject" maxlength="100" /></li>
+    <li>Message: <input type="text" name="message" /></li>
+    <li>Sender: <input type="text" name="sender" /></li>
+    <li>Cc myself: <input type="checkbox" name="cc_myself" /></li>
+    <li>Priority: <input type="text" name="priority" /></li>
+
+It's possible to subclass multiple forms, treating forms as "mix-ins." In this
+example, ``BeatleForm`` subclasses both ``PersonForm`` and ``InstrumentForm``
+(in that order), and its field list includes the fields from the parent
+classes::
+
+    >>> class PersonForm(Form):
+    ...     first_name = CharField()
+    ...     last_name = CharField()
+    >>> class InstrumentForm(Form):
+    ...     instrument = CharField()
+    >>> class BeatleForm(PersonForm, InstrumentForm):
+    ...     haircut_type = CharField()
+    >>> b = BeatleForm(auto_id=False)
+    >>> print b.as_ul()
+    <li>First name: <input type="text" name="first_name" /></li>
+    <li>Last name: <input type="text" name="last_name" /></li>
+    <li>Instrument: <input type="text" name="instrument" /></li>
+    <li>Haircut type: <input type="text" name="haircut_type" /></li>
+
+Fields
+======
+
+When you create a ``Form`` class, the most important part is defining the
+fields of the form. Each field has custom validation logic, along with a few
+other hooks.
+
+Although the primary way you'll use ``Field`` classes is in ``Form`` classes,
+you can also instantiate them and use them directly to get a better idea of
+how they work. Each ``Field`` instance has a ``clean()`` method, which takes
+a single argument and either raises a ``django.newforms.ValidationError``
+exception or returns the clean value::
+
+    >>> f = forms.EmailField()
+    >>> f.clean('foo@example.com')
+    u'foo@example.com'
+    >>> f.clean(u'foo@example.com')
+    u'foo@example.com'
+    >>> f.clean('invalid e-mail address')
+    Traceback (most recent call last):
+    ...
+    ValidationError: [u'Enter a valid e-mail address.']
+
+If you've used Django's old forms/validation framework, take care in noticing
+this ``ValidationError`` is different than the previous ``ValidationError``.
+This one lives at ``django.newforms.ValidationError`` rather than
+``django.core.validators.ValidationError``.
+
+Core field arguments
+--------------------
+
+Each ``Field`` class constructor takes at least these arguments. Some
+``Field`` classes take additional, field-specific arguments, but the following
+should *always* be accepted:
+
+``required``
+~~~~~~~~~~~~
+
+By default, each ``Field`` class assumes the value is required, so if you pass
+an empty value -- either ``None`` or the empty string (``""``) -- then
+``clean()`` will raise a ``ValidationError`` exception::
+
+    >>> f = forms.CharField()
+    >>> f.clean('foo')
+    u'foo'
+    >>> f.clean('')
+    Traceback (most recent call last):
+    ...
+    ValidationError: [u'This field is required.']
+    >>> f.clean(None)
+    Traceback (most recent call last):
+    ...
+    ValidationError: [u'This field is required.']
+    >>> f.clean(' ')
+    u' '
+    >>> f.clean(0)
+    u'0'
+    >>> f.clean(True)
+    u'True'
+    >>> f.clean(False)
+    u'False'
+
+To specify that a field is *not* required, pass ``required=False`` to the
+``Field`` constructor::
+
+    >>> f = forms.CharField(required=False)
+    >>> f.clean('foo')
+    u'foo'
+    >>> f.clean('')
+    u''
+    >>> f.clean(None)
+    u''
+    >>> f.clean(0)
+    u'0'
+    >>> f.clean(True)
+    u'True'
+    >>> f.clean(False)
+    u'False'
+
+If a ``Field`` has ``required=False`` and you pass ``clean()`` an empty value,
+then ``clean()`` will return a *normalized* empty value rather than raising
+``ValidationError``. For ``CharField``, this will be a Unicode empty string.
+For other ``Field`` classes, it might be ``None``. (This varies from field to
+field.)
+
+``label``
+~~~~~~~~~
+
+The ``label`` argument lets you specify the "human-friendly" label for this
+field. This is used when the ``Field`` is displayed in a ``Form``.
+
+As explained in "Outputting forms as HTML" above, the default label for a
+``Field`` is generated from the field name by converting all underscores to
+spaces and upper-casing the first letter. Specify ``label`` if that default
+behavior doesn't result in an adequate label.
+
+Here's a full example ``Form`` that implements ``label`` for two of its fields.
+We've specified ``auto_id=False`` to simplify the output::
+
+    >>> class CommentForm(forms.Form):
+    ...     name = forms.CharField(label='Your name')
+    ...     url = forms.URLField(label='Your Web site', required=False)
+    ...     comment = forms.CharField()
+    >>> f = CommentForm(auto_id=False)
+    >>> print f
+    <tr><th>Your name:</th><td><input type="text" name="name" /></td></tr>
+    <tr><th>Your Web site:</th><td><input type="text" name="url" /></td></tr>
+    <tr><th>Comment:</th><td><input type="text" name="comment" /></td></tr>
+
+``initial``
+~~~~~~~~~~~
+
+The ``initial`` argument lets you specify the initial value to use when
+rendering this ``Field`` in an unbound ``Form``.
+
+The use-case for this is when you want to display an "empty" form in which a
+field is initialized to a particular value. For example::
+
+    >>> class CommentForm(forms.Form):
+    ...     name = forms.CharField(initial='Your name')
+    ...     url = forms.URLField(initial='http://')
+    ...     comment = forms.CharField()
+    >>> f = CommentForm(auto_id=False)
+    >>> print f
+    <tr><th>Name:</th><td><input type="text" name="name" value="Your name" /></td></tr>
+    <tr><th>Url:</th><td><input type="text" name="url" value="http://" /></td></tr>
+    <tr><th>Comment:</th><td><input type="text" name="comment" /></td></tr>
+
+You may be thinking, why not just pass a dictionary of the initial values as
+data when displaying the form? Well, if you do that, you'll trigger validation,
+and the HTML output will include any validation errors::
+
+    >>> class CommentForm(forms.Form):
+    ...     name = forms.CharField()
+    ...     url = forms.URLField()
+    ...     comment = forms.CharField()
+    >>> default_data = {'name': 'Your name', 'url': 'http://'}
+    >>> f = CommentForm(default_data, auto_id=False)
+    >>> print f
+    <tr><th>Name:</th><td><input type="text" name="name" value="Your name" /></td></tr>
+    <tr><th>Url:</th><td><ul class="errorlist"><li>Enter a valid URL.</li></ul><input type="text" name="url" value="http://" /></td></tr>
+    <tr><th>Comment:</th><td><ul class="errorlist"><li>This field is required.</li></ul><input type="text" name="comment" /></td></tr>
+
+This is why ``initial`` values are only displayed for unbound forms. For bound
+forms, the HTML output will use the bound data.
+
+Also note that ``initial`` values are *not* used as "fallback" data in
+validation if a particular field's value is not given. ``initial`` values are
+*only* intended for initial form display::
+
+    >>> class CommentForm(forms.Form):
+    ...     name = forms.CharField(initial='Your name')
+    ...     url = forms.URLField(initial='http://')
+    ...     comment = forms.CharField()
+    >>> data = {'name': '', 'url': '', 'comment': 'Foo'}
+    >>> f = CommentForm(data)
+    >>> f.is_valid()
+    False
+    # The form does *not* fall back to using the initial values.
+    >>> f.errors
+    {'url': [u'This field is required.'], 'name': [u'This field is required.']}
+
+``widget``
+~~~~~~~~~~
+
+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 by one of the convenience ``Form``
+methods (e.g., ``as_ul()``).
+
+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
+----------------------
+
+The ``initial`` argument to ``Field`` (explained above) lets you hard-code the
+initial value for a ``Field`` -- but what if you want to declare the initial
+value at runtime? For example, you might want to fill in a ``username`` field
+with the username of the current session.
+
+To accomplish this, use the ``initial`` argument to a ``Form``. This argument,
+if given, should be a dictionary mapping field names to initial values. Only
+include the fields for which you're specifying an initial value; it's not
+necessary to include every field in your form. For example::
+
+    >>> class CommentForm(forms.Form):
+    ...     name = forms.CharField()
+    ...     url = forms.URLField()
+    ...     comment = forms.CharField()
+    >>> f = CommentForm(initial={'name': 'your username'}, auto_id=False)
+    >>> print f
+    <tr><th>Name:</th><td><input type="text" name="name" value="your username" /></td></tr>
+    <tr><th>Url:</th><td><input type="text" name="url" /></td></tr>
+    <tr><th>Comment:</th><td><input type="text" name="comment" /></td></tr>
+    >>> f = CommentForm(initial={'name': 'another username'}, auto_id=False)
+    >>> print f
+    <tr><th>Name:</th><td><input type="text" name="name" value="another username" /></td></tr>
+    <tr><th>Url:</th><td><input type="text" name="url" /></td></tr>
+    <tr><th>Comment:</th><td><input type="text" name="comment" /></td></tr>
+
+Just like the ``initial`` parameter to ``Field``, these values are only
+displayed for unbound forms, and they're not used as fallback values if a
+particular value isn't provided.
+
+Finally, note that if a ``Field`` defines ``initial`` *and* you include
+``initial`` when instantiating the ``Form``, then the latter ``initial`` will
+have precedence. In this example, ``initial`` is provided both at the field
+level and at the form instance level, and the latter gets precedence::
+
+    >>> class CommentForm(forms.Form):
+    ...     name = forms.CharField(initial='class')
+    ...     url = forms.URLField()
+    ...     comment = forms.CharField()
+    >>> f = CommentForm(initial={'name': 'instance'}, auto_id=False)
+    >>> print f
+    <tr><th>Name:</th><td><input type="text" name="name" value="instance" /></td></tr>
+    <tr><th>Url:</th><td><input type="text" name="url" /></td></tr>
+    <tr><th>Comment:</th><td><input type="text" name="comment" /></td></tr>
+
+Built-in ``Field`` classes
+--------------------------
+
+Naturally, the ``newforms`` library comes with a set of ``Field`` classes that
+represent common validation needs. This section documents each built-in field.
+
+For each field, we describe the default widget used if you don't specify
+``widget``. We also specify the value returned when you provide an empty value
+(see the section on ``required`` above to understand what that means).
+
+``BooleanField``
+~~~~~~~~~~~~~~~~
+
+    * Default widget: ``CheckboxInput``
+    * Empty value: ``None``
+    * Normalizes to: A Python ``True`` or ``False`` value.
+    * Validates nothing (i.e., it never raises a ``ValidationError``).
+
+``CharField``
+~~~~~~~~~~~~~
+
+    * Default widget: ``TextInput``
+    * Empty value: ``''`` (an empty string)
+    * Normalizes to: A Unicode object.
+    * Validates nothing, unless ``max_length`` or ``min_length`` is provided.
+
+Has two optional arguments for validation, ``max_length`` and ``min_length``.
+If provided, these arguments ensure that the string is at most or at least the
+given length.
+
+``ChoiceField``
+~~~~~~~~~~~~~~~
+
+    * Default widget: ``Select``
+    * Empty value: ``''`` (an empty string)
+    * Normalizes to: A Unicode object.
+    * Validates that the given value exists in the list of choices.
+
+Takes one extra argument, ``choices``, which is an iterable (e.g., a list or
+tuple) of 2-tuples to use as choices for this field.
+
+``DateField``
+~~~~~~~~~~~~~
+
+    * Default widget: ``TextInput``
+    * Empty value: ``None``
+    * Normalizes to: A Python ``datetime.date`` object.
+    * Validates that the given value is either a ``datetime.date``,
+      ``datetime.datetime`` or string formatted in a particular date format.
+
+Takes one optional argument, ``input_formats``, which is a list of formats used
+to attempt to convert a string to a valid ``datetime.date`` object.
+
+If no ``input_formats`` argument is provided, the default input formats are::
+
+    '%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'
+    '%d %b %Y', '%d %b, %Y',            # '25 Oct 2006', '25 Oct, 2006'
+    '%B %d %Y', '%B %d, %Y',            # 'October 25 2006', 'October 25, 2006'
+    '%d %B %Y', '%d %B, %Y',            # '25 October 2006', '25 October, 2006'
+
+``DateTimeField``
+~~~~~~~~~~~~~~~~~
+
+    * Default widget: ``TextInput``
+    * Empty value: ``None``
+    * Normalizes to: A Python ``datetime.datetime`` object.
+    * Validates that the given value is either a ``datetime.datetime``,
+      ``datetime.date`` or string formatted in a particular datetime format.
+
+Takes one optional argument, ``input_formats``, which is a list of formats used
+to attempt to convert a string to a valid ``datetime.datetime`` object.
+
+If no ``input_formats`` argument is provided, the default input formats are::
+
+    '%Y-%m-%d %H:%M:%S',     # '2006-10-25 14:30:59'
+    '%Y-%m-%d %H:%M',        # '2006-10-25 14:30'
+    '%Y-%m-%d',              # '2006-10-25'
+    '%m/%d/%Y %H:%M:%S',     # '10/25/2006 14:30:59'
+    '%m/%d/%Y %H:%M',        # '10/25/2006 14:30'
+    '%m/%d/%Y',              # '10/25/2006'
+    '%m/%d/%y %H:%M:%S',     # '10/25/06 14:30:59'
+    '%m/%d/%y %H:%M',        # '10/25/06 14:30'
+    '%m/%d/%y',              # '10/25/06'
+
+``EmailField``
+~~~~~~~~~~~~~~
+
+    * Default widget: ``TextInput``
+    * Empty value: ``''`` (an empty string)
+    * Normalizes to: A Unicode object.
+    * Validates that the given value is a valid e-mail address, using a
+      moderately complex regular expression.
+
+Has two optional arguments for validation, ``max_length`` and ``min_length``.
+If provided, these arguments ensure that the string is at most or at least the
+given length.
+
+``IntegerField``
+~~~~~~~~~~~~~~~~
+
+    * Default widget: ``TextInput``
+    * Empty value: ``None``
+    * Normalizes to: A Python integer or long integer.
+    * Validates that the given value is an integer. Leading and trailing
+      whitespace is allowed, as in Python's ``int()`` function.
+
+``MultipleChoiceField``
+~~~~~~~~~~~~~~~~~~~~~~~
+
+    * Default widget: ``SelectMultiple``
+    * Empty value: ``[]`` (an empty list)
+    * Normalizes to: A list of Unicode objects.
+    * Validates that every value in the given list of values exists in the list
+      of choices.
+
+Takes one extra argument, ``choices``, which is an iterable (e.g., a list or
+tuple) of 2-tuples to use as choices for this field.
+
+``NullBooleanField``
+~~~~~~~~~~~~~~~~~~~~
+
+    * Default widget: ``NullBooleanSelect``
+    * Empty value: ``None``
+    * Normalizes to: A Python ``True``, ``False`` or ``None`` value.
+    * Validates nothing (i.e., it never raises a ``ValidationError``).
+
+``RegexField``
+~~~~~~~~~~~~~~
+
+    * Default widget: ``TextInput``
+    * Empty value: ``''`` (an empty string)
+    * Normalizes to: A Unicode object.
+    * Validates that the given value matches against a certain regular
+      expression.
+
+Takes one required argument, ``regex``, which is a regular expression specified
+either as a string or a compiled regular expression object.
+
+Also takes the following optional arguments:
+
+    ======================  =====================================================
+    Argument                Description
+    ======================  =====================================================
+    ``max_length``          Ensures the string has at most this many characters.
+    ``min_length``          Ensures the string has at least this many characters.
+    ``error_message``       Error message to return for failed validation. If no
+                            message is provided, a generic error message will be
+                            used.
+    ======================  =====================================================
+
+``TimeField``
+~~~~~~~~~~~~~
+
+    * Default widget: ``TextInput``
+    * Empty value: ``None``
+    * Normalizes to: A Python ``datetime.time`` object.
+    * Validates that the given value is either a ``datetime.time`` or string
+      formatted in a particular time format.
+
+Takes one optional argument, ``input_formats``, which is a list of formats used
+to attempt to convert a string to a valid ``datetime.time`` object.
+
+If no ``input_formats`` argument is provided, the default input formats are::
+
+    '%H:%M:%S',     # '14:30:59'
+    '%H:%M',        # '14:30'
+
+``URLField``
+~~~~~~~~~~~~
+
+    * Default widget: ``TextInput``
+    * Empty value: ``''`` (an empty string)
+    * Normalizes to: A Unicode object.
+    * Validates that the given value is a valid URL.
+
+Takes the following optional arguments:
+
+    ========================  =====================================================
+    Argument                  Description
+    ========================  =====================================================
+    ``max_length``            Ensures the string has at most this many characters.
+    ``min_length``            Ensures the string has at least this many characters.
+    ``verify_exists``         If ``True``, the validator will attempt to load the
+                              given URL, raising ``ValidationError`` if the page
+                              gives a 404. Defaults to ``False``.
+    ``validator_user_agent``  String used as the user-agent used when checking for
+                              a URL's existence. Defaults to the value of the
+                              ``URL_VALIDATOR_USER_AGENT`` setting.
+    ========================  =====================================================
+
+Slightly complex built-in ``Field`` classes
+-------------------------------------------
+
+The following are not yet documented here. See the unit tests, linked-to from
+the bottom of this document, for examples of their use.
+
+``ComboField``
+~~~~~~~~~~~~~~
+
+``MultiValueField``
+~~~~~~~~~~~~~~~~~~~
+
+``SplitDateTimeField``
+~~~~~~~~~~~~~~~~~~~~~~
+
+Creating custom fields
+----------------------
+
+If the built-in ``Field`` classes don't meet your needs, you can easily create
+custom ``Field`` classes. To do this, just create a subclass of
+``django.newforms.Field``. Its only requirements are that it implement a
+``clean()`` method and that its ``__init__()`` method accept the core arguments
+mentioned above (``required``, ``label``, ``initial``, ``widget``,
+``help_text``).
+
+Custom form and field validation
+---------------------------------
+
+Form validation happens when the data is cleaned. If you want to customise
+this process, there are various places you can change, each one serving a
+different purpose. Thee types of cleaning methods are run during form
+processing. These are normally executed when you call the ``is_valid()``
+method on a form. There are other things that can trigger cleaning and
+validation (accessing the ``errors`` attribute or calling ``full_clean()``
+directly), but normally they won't be needed.
+
+In general, any cleaning method can raise ``ValidationError`` if there is a
+problem with the data it is processing, passing the relevant error message to
+the ``ValidationError`` constructor. If no ``ValidationError`` is raised, the
+method should return the cleaned (normalised) data as a Python object.
+
+If you detect multiple errors during a cleaning method and wish to signal all
+of them to the form submitter, it is possible to pass a list of errors to the
+``ValidationError`` constructor.
+
+The three types of cleaning methods are:
+
+    * The ``clean()`` method on a Field subclass. This is responsible
+      for cleaning the data in a way that is generic for that type of field.
+      For example, a FloatField will turn the data into a Python ``float`` or
+      raise a ``ValidationError``.
+
+    * The ``clean_<fieldname>()`` method in a form subclass -- where
+      ``<fieldname>`` is replaced with the name of the form field attribute.
+      This method does any cleaning that is specific to that particular
+      attribute, unrelated to the type of field that it is. This method is not
+      passed any parameters. You will need to look up the value of the field
+      in ``self.cleaned_data`` and remember that it will be a Python object
+      at this point, not the original string submitted in the form (it will be
+      in ``cleaned_data`` because the general field ``clean()`` method, above,
+      has already cleaned the data once).
+
+      For example, if you wanted to validate that the contents of a
+      ``CharField`` called ``serialnumber`` was unique,
+      ``clean_serialnumber()`` would be the right place to do this. You don't
+      need a specific field (it's just a ``CharField``), but you want a
+      formfield-specific piece of validation and, possibly,
+      cleaning/normalizing the data.
+
+    * The Form subclass's ``clean()`` method. This method can perform
+      any validation that requires access to multiple fields from the form at
+      once. This is where you might put in things to check that if field ``A``
+      is supplied, field ``B`` must contain a valid email address and the
+      like. The data that this method returns is the final ``cleaned_data``
+      attribute for the form, so don't forget to return the full list of
+      cleaned data if you override this method (by default, ``Form.clean()``
+      just returns ``self.cleaned_data``).
+
+      Note that any errors raised by your ``Form.clean()`` override will not
+      be associated with any field in particular. They go into a special
+      "field" (called ``__all__``, which you can access via the
+      ``non_field_errors()`` method if you need to.
+
+These methods are run in the order given above, one field at a time.  That is,
+for each field in the form (in the order they are declared in the form
+definition), the ``Field.clean()`` method (or it's override) is run, then
+``clean_<fieldname>()``. Finally, once those two methods are run for every
+field, the ``Form.clean()`` method, or it's override, is executed.
+
+As mentioned above, any of these methods can raise a ``ValidationError``. For
+any field, if the ``Field.clean()`` method raises a ``ValidationError``, any
+field-specific cleaning method is not called. However, the cleaning methods
+for all remaining fields are still executed.
+
+The ``clean()`` method for the ``Form`` class or subclass is always run. If
+that method raises a ``ValidationError``, ``cleaned_data`` will be an empty
+dictionary.
+
+The previous paragraph means that if you are overriding ``Form.clean()``, you
+should iterate through ``self.cleaned_data.items()``, possibly considering the
+``_errors`` dictionary attribute on the form as well. In this way, you will
+already know which fields have passed their individual validation requirements.
+
+A simple example
+~~~~~~~~~~~~~~~~
+
+Here's a simple example of a custom field that validates its input is a string
+containing comma-separated e-mail addresses, with at least one address. We'll
+keep it simple and assume e-mail validation is contained in a function called
+``is_valid_email()``. The full class::
+
+    from django import newforms as forms
+
+    class MultiEmailField(forms.Field):
+        def clean(self, value):
+            emails = value.split(',')
+            for email in emails:
+                if not is_valid_email(email):
+                    raise forms.ValidationError('%s is not a valid e-mail address.' % email)
+            if not emails:
+                raise forms.ValidationError('Enter at least one e-mail address.')
+            return emails
+
+Let's alter the ongoing ``ContactForm`` example to demonstrate how you'd use
+this in a form. Simply use ``MultiEmailField`` instead of ``forms.EmailField``,
+like so::
+
+    class ContactForm(forms.Form):
+        subject = forms.CharField(max_length=100)
+        message = forms.CharField()
+        senders = MultiEmailField()
+        cc_myself = forms.BooleanField()
+
+Generating forms for models
+===========================
+
+If you're building a database-driven app, chances are you'll have forms that
+map closely to Django models. For instance, you might have a ``BlogComment``
+model, and you want to create a form that lets people submit comments. In this
+case, it would be redundant to define the field types in your form, because
+you've already defined the fields in your model.
+
+For this reason, Django provides a few helper functions that let you create a
+``Form`` class from a Django model.
+
+``form_for_model()``
+--------------------
+
+The method ``django.newforms.form_for_model()`` creates a form based on the
+definition of a specific model. Pass it the model class, and it will return a
+``Form`` class that contains a form field for each model field.
+
+For example::
+
+    >>> from django.newforms import form_for_model
+
+    # Create the form class.
+    >>> ArticleForm = form_for_model(Article)
+
+    # Create an empty form instance.
+    >>> f = ArticleForm()
+
+It bears repeating that ``form_for_model()`` takes the model *class*, not a
+model instance, and it returns a ``Form`` *class*, not a ``Form`` instance.
+
+Field types
+~~~~~~~~~~~
+
+The generated ``Form`` class will have a form field for every model field. Each
+model field has a corresponding default form field. For example, a
+``CharField`` on a model is represented as a ``CharField`` on a form. A
+model ``ManyToManyField`` is represented as a ``MultipleChoiceField``. Here is
+the full list of conversions:
+
+    ===============================  ========================================
+    Model field                      Form field
+    ===============================  ========================================
+    ``AutoField``                    Not represented in the form
+    ``BooleanField``                 ``BooleanField``
+    ``CharField``                    ``CharField`` with ``max_length`` set to
+                                     the model field's ``maxlength``
+    ``CommaSeparatedIntegerField``   ``CharField``
+    ``DateField``                    ``DateField``
+    ``DateTimeField``                ``DateTimeField``
+    ``DecimalField``                 ``DecimalField``
+    ``EmailField``                   ``EmailField``
+    ``FileField``                    ``CharField``
+    ``FilePathField``                ``CharField``
+    ``FloatField``                   ``FloatField``
+    ``ForeignKey``                   ``ModelChoiceField`` (see below)
+    ``ImageField``                   ``CharField``
+    ``IntegerField``                 ``IntegerField``
+    ``IPAddressField``               ``CharField``
+    ``ManyToManyField``              ``ModelMultipleChoiceField`` (see
+                                     below)
+    ``NullBooleanField``             ``CharField``
+    ``PhoneNumberField``             ``USPhoneNumberField``
+                                     (from ``django.contrib.localflavor.us``)
+    ``PositiveIntegerField``         ``IntegerField``
+    ``PositiveSmallIntegerField``    ``IntegerField``
+    ``SlugField``                    ``CharField``
+    ``SmallIntegerField``            ``IntegerField``
+    ``TextField``                    ``CharField`` with ``widget=Textarea``
+    ``TimeField``                    ``TimeField``
+    ``URLField``                     ``URLField`` with ``verify_exists`` set
+                                     to the model field's ``verify_exists``
+    ``USStateField``                 ``CharField`` with
+                                     ``widget=USStateSelect``
+                                     (``USStateSelect`` is from
+                                     ``django.contrib.localflavor.us``)
+    ``XMLField``                     ``CharField`` with ``widget=Textarea``
+    ===============================  ========================================
+
+
+.. note::
+    The ``FloatField`` form field and ``DecimalField`` model and form fields
+    are new in the development version.
+
+As you might expect, the ``ForeignKey`` and ``ManyToManyField`` model field
+types are special cases:
+
+    * ``ForeignKey`` is represented by ``django.newforms.ModelChoiceField``,
+      which is a ``ChoiceField`` whose choices are a model ``QuerySet``.
+
+    * ``ManyToManyField`` is represented by
+      ``django.newforms.ModelMultipleChoiceField``, which is a
+      ``MultipleChoiceField`` whose choices are a model ``QuerySet``.
+
+In addition, each generated form field has attributes set as follows:
+
+    * If the model field has ``blank=True``, then ``required`` is set to
+      ``False`` on the form field. Otherwise, ``required=True``.
+
+    * The form field's ``label`` is set to the ``verbose_name`` of the model
+      field, with the first character capitalized.
+
+    * The form field's ``help_text`` is set to the ``help_text`` of the model
+      field.
+
+    * If the model field has ``choices`` set, then the form field's ``widget``
+      will be set to ``Select``, with choices coming from the model field's
+      ``choices``.
+
+Finally, note that you can override the form field used for a given model
+field. See "Overriding the default field types" below.
+
+A full example
+~~~~~~~~~~~~~~
+
+Consider this set of models::
+
+    from django.db import models
+
+    TITLE_CHOICES = (
+        ('MR', 'Mr.'),
+        ('MRS', 'Mrs.'),
+        ('MS', 'Ms.'),
+    )
+
+    class Author(models.Model):
+        name = models.CharField(maxlength=100)
+        title = models.CharField(maxlength=3, choices=TITLE_CHOICES)
+        birth_date = models.DateField(blank=True, null=True)
+
+        def __str__(self):
+            return self.name
+
+    class Book(models.Model):
+        name = models.CharField(maxlength=100)
+        authors = models.ManyToManyField(Author)
+
+With these models, a call to ``form_for_model(Author)`` would return a ``Form``
+class equivalent to this::
+
+    class AuthorForm(forms.Form):
+        name = forms.CharField(max_length=100)
+        title = forms.CharField(max_length=3,
+                    widget=forms.Select(choices=TITLE_CHOICES))
+        birth_date = forms.DateField(required=False)
+
+A call to ``form_for_model(Book)`` would return a ``Form`` class equivalent to
+this::
+
+    class BookForm(forms.Form):
+        name = forms.CharField(max_length=100)
+        authors = forms.ModelMultipleChoiceField(queryset=Author.objects.all())
+
+The ``save()`` method
+~~~~~~~~~~~~~~~~~~~~~
+
+Every form produced by ``form_for_model()`` also has a ``save()`` method. This
+method creates and saves a database object from the data bound to the form. For
+example::
+
+    # Create a form instance from POST data.
+    >>> f = ArticleForm(request.POST)
+
+    # Save a new Article object from the form's data.
+    >>> new_article = f.save()
+
+Note that ``save()`` will raise a ``ValueError`` if the data in the form
+doesn't validate -- i.e., ``if form.errors``.
+
+Using an alternate base class
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If you want to add custom methods to the form generated by
+``form_for_model()``, write a class that extends ``django.newforms.BaseForm``
+and contains your custom methods. Then, use the ``form`` argument to
+``form_for_model()`` to tell it to use your custom form as its base class.
+For example::
+
+    # Create the new base class.
+    >>> class MyBase(BaseForm):
+    ...     def my_method(self):
+    ...         # Do whatever the method does
+
+    # Create the form class with a different base class.
+    >>> ArticleForm = form_for_model(Article, form=MyBase)
+
+    # Instantiate the form.
+    >>> f = ArticleForm()
+
+    # Use the base class method.
+    >>> f.my_method()
+
+Using a subset of fields on the form
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+**New in Django development version**
+
+In some cases, you may not want all the model fields to appear on the generated
+form. There are two ways of telling ``form_for_model()`` to use only a subset
+of the model fields:
+
+    1. Set ``editable=False`` on the model field. As a result, *any* form
+       created from the model via ``form_for_model()`` will not include that
+       field.
+
+    2. Use the ``fields`` argument to ``form_for_model()``. This argument, if
+       given, should be a list of field names to include in the form.
+
+       For example, if you want a form for the ``Author`` model (defined above)
+       that includes only the ``name`` and ``title`` fields, you would specify
+       ``fields`` like this::
+
+           PartialArticleForm = form_for_model(Author, fields=('name', 'title'))
+
+.. note::
+
+    If you specify ``fields`` when creating a form with ``form_for_model()``,
+    make sure that the fields that are *not* specified can provide default
+    values, or are allowed to have a value of ``None``. If a field isn't
+    specified on a form, the object created from the form can't provide
+    a value for that attribute, which will prevent the new instance from
+    being saved.
+
+Overriding the default field types
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The default field types, as described in the "Field types" table above, are
+sensible defaults; if you have a ``DateField`` in your model, chances are you'd
+want that to be represented as a ``DateField`` in your form. But
+``form_for_model()`` gives you the flexibility of changing the form field type
+for a given model field. You do this by specifying a **formfield callback**.
+
+A formfield callback is a function that, when provided with a model field,
+returns a form field instance. When constructing a form, ``form_for_model()``
+asks the formfield callback to provide form field types.
+
+By default, ``form_for_model()`` calls the ``formfield()`` method on the model
+field::
+
+    def default_callback(field, **kwargs):
+        return field.formfield(**kwargs)
+
+The ``kwargs`` are any keyword arguments that might be passed to the form
+field, such as ``required=True`` or ``label='Foo'``.
+
+For example, if you wanted to use ``MyDateFormField`` for any ``DateField``
+field on the model, you could define the callback::
+
+    >>> def my_callback(field, **kwargs):
+    ...     if isinstance(field, models.DateField):
+    ...         return MyDateFormField(**kwargs)
+    ...     else:
+    ...         return field.formfield(**kwargs)
+
+    >>> ArticleForm = form_for_model(formfield_callback=my_callback)
+
+Note that your callback needs to handle *all* possible model field types, not
+just the ones that you want to behave differently to the default. That's why
+this example has an ``else`` clause that implements the default behavior.
+
+Finding the model associated with a form
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The model class that was used to construct the form is available
+using the ``_model`` property of the generated form::
+
+    >>> ArticleForm = form_for_model(Article)
+    >>> ArticleForm._model
+    <class 'myapp.models.Article'>
+
+``form_for_instance()``
+-----------------------
+
+``form_for_instance()`` is like ``form_for_model()``, but it takes a model
+instance instead of a model class::
+
+    # Create an Author.
+    >>> a = Author(name='Joe Smith', title='MR', birth_date=None)
+    >>> a.save()
+
+    # Create a form for this particular Author.
+    >>> AuthorForm = form_for_instance(a)
+
+    # Instantiate the form.
+    >>> f = AuthorForm()
+
+When a form created by ``form_for_instance()`` is created, the initial
+data values for the form fields are drawn from the instance. However,
+this data is not bound to the form. You will need to bind data to the
+form before the form can be saved.
+
+When you call ``save()`` on a form created by ``form_for_instance()``,
+the database instance will be updated. As in ``form_for_model()``, ``save()``
+will raise ``ValueError`` if the data doesn't validate.
+
+``form_for_instance()`` has ``form``, ``fields`` and ``formfield_callback``
+arguments that behave the same way as they do for ``form_for_model()``.
+
+When should you use ``form_for_model()`` and ``form_for_instance()``?
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+The ``form_for_model()`` and ``form_for_instance()`` functions are meant to be
+shortcuts for the common case. If you want to create a form whose fields map to
+more than one model, or a form that contains fields that *aren't* on a model,
+you shouldn't use these shortcuts. Creating a ``Form`` class the "long" way
+isn't that difficult, after all.
+
 More coming soon
 ================
 
@@ -290,11 +1641,5 @@ http://code.djangoproject.com/browser/django/trunk/tests/regressiontests/forms/t
 -- the unit tests for ``django.newforms``. This can give you a good idea of
 what's possible.
 
-Using forms to validate data
-----------------------------
-
-Using forms with templates
-==========================
-
-Using forms in views
-====================
+If you're really itching to learn and use this library, please be patient.
+We're working hard on finishing both the code and documentation.