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1035 lines
36 KiB
Text
1035 lines
36 KiB
Text
===========
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Form fields
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===========
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.. module:: django.forms.fields
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:synopsis: Django's built-in form fields.
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.. currentmodule:: django.forms
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.. class:: Field(**kwargs)
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When you create a ``Form`` class, the most important part is defining the
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fields of the form. Each field has custom validation logic, along with a few
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other hooks.
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.. method:: Field.clean(value)
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Although the primary way you'll use ``Field`` classes is in ``Form`` classes,
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you can also instantiate them and use them directly to get a better idea of
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how they work. Each ``Field`` instance has a ``clean()`` method, which takes
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a single argument and either raises a ``django.forms.ValidationError``
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exception or returns the clean value::
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>>> from django import forms
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>>> f = forms.EmailField()
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>>> f.clean('foo@example.com')
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u'foo@example.com'
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>>> f.clean('invalid email address')
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Traceback (most recent call last):
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...
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ValidationError: [u'Enter a valid email address.']
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Core field arguments
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--------------------
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Each ``Field`` class constructor takes at least these arguments. Some
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``Field`` classes take additional, field-specific arguments, but the following
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should *always* be accepted:
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``required``
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~~~~~~~~~~~~
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.. attribute:: Field.required
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By default, each ``Field`` class assumes the value is required, so if you pass
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an empty value -- either ``None`` or the empty string (``""``) -- then
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``clean()`` will raise a ``ValidationError`` exception::
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>>> f = forms.CharField()
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>>> f.clean('foo')
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u'foo'
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>>> f.clean('')
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Traceback (most recent call last):
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...
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ValidationError: [u'This field is required.']
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>>> f.clean(None)
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Traceback (most recent call last):
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...
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ValidationError: [u'This field is required.']
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>>> f.clean(' ')
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u' '
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>>> f.clean(0)
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u'0'
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>>> f.clean(True)
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u'True'
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>>> f.clean(False)
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u'False'
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To specify that a field is *not* required, pass ``required=False`` to the
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``Field`` constructor::
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>>> f = forms.CharField(required=False)
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>>> f.clean('foo')
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u'foo'
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>>> f.clean('')
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u''
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>>> f.clean(None)
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u''
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>>> f.clean(0)
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u'0'
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>>> f.clean(True)
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u'True'
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>>> f.clean(False)
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u'False'
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If a ``Field`` has ``required=False`` and you pass ``clean()`` an empty value,
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then ``clean()`` will return a *normalized* empty value rather than raising
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``ValidationError``. For ``CharField``, this will be a Unicode empty string.
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For other ``Field`` classes, it might be ``None``. (This varies from field to
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field.)
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``label``
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~~~~~~~~~
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.. attribute:: Field.label
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The ``label`` argument lets you specify the "human-friendly" label for this
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field. This is used when the ``Field`` is displayed in a ``Form``.
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As explained in "Outputting forms as HTML" above, the default label for a
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``Field`` is generated from the field name by converting all underscores to
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spaces and upper-casing the first letter. Specify ``label`` if that default
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behavior doesn't result in an adequate label.
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Here's a full example ``Form`` that implements ``label`` for two of its fields.
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We've specified ``auto_id=False`` to simplify the output::
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>>> class CommentForm(forms.Form):
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... name = forms.CharField(label='Your name')
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... url = forms.URLField(label='Your Web site', required=False)
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... comment = forms.CharField()
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>>> f = CommentForm(auto_id=False)
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>>> print(f)
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<tr><th>Your name:</th><td><input type="text" name="name" /></td></tr>
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<tr><th>Your Web site:</th><td><input type="url" name="url" /></td></tr>
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<tr><th>Comment:</th><td><input type="text" name="comment" /></td></tr>
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``initial``
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~~~~~~~~~~~
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.. attribute:: Field.initial
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The ``initial`` argument lets you specify the initial value to use when
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rendering this ``Field`` in an unbound ``Form``.
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To specify dynamic initial data, see the :attr:`Form.initial` parameter.
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The use-case for this is when you want to display an "empty" form in which a
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field is initialized to a particular value. For example::
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>>> class CommentForm(forms.Form):
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... name = forms.CharField(initial='Your name')
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... url = forms.URLField(initial='http://')
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... comment = forms.CharField()
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>>> f = CommentForm(auto_id=False)
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>>> print(f)
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<tr><th>Name:</th><td><input type="text" name="name" value="Your name" /></td></tr>
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<tr><th>Url:</th><td><input type="url" name="url" value="http://" /></td></tr>
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<tr><th>Comment:</th><td><input type="text" name="comment" /></td></tr>
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You may be thinking, why not just pass a dictionary of the initial values as
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data when displaying the form? Well, if you do that, you'll trigger validation,
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and the HTML output will include any validation errors::
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>>> class CommentForm(forms.Form):
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... name = forms.CharField()
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... url = forms.URLField()
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... comment = forms.CharField()
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>>> default_data = {'name': 'Your name', 'url': 'http://'}
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>>> f = CommentForm(default_data, auto_id=False)
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>>> print(f)
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<tr><th>Name:</th><td><input type="text" name="name" value="Your name" /></td></tr>
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<tr><th>Url:</th><td><ul class="errorlist"><li>Enter a valid URL.</li></ul><input type="url" name="url" value="http://" /></td></tr>
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<tr><th>Comment:</th><td><ul class="errorlist"><li>This field is required.</li></ul><input type="text" name="comment" /></td></tr>
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This is why ``initial`` values are only displayed for unbound forms. For bound
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forms, the HTML output will use the bound data.
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Also note that ``initial`` values are *not* used as "fallback" data in
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validation if a particular field's value is not given. ``initial`` values are
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*only* intended for initial form display::
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>>> class CommentForm(forms.Form):
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... name = forms.CharField(initial='Your name')
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... url = forms.URLField(initial='http://')
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... comment = forms.CharField()
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>>> data = {'name': '', 'url': '', 'comment': 'Foo'}
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>>> f = CommentForm(data)
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>>> f.is_valid()
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False
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# The form does *not* fall back to using the initial values.
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>>> f.errors
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{'url': [u'This field is required.'], 'name': [u'This field is required.']}
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Instead of a constant, you can also pass any callable::
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>>> import datetime
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>>> class DateForm(forms.Form):
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... day = forms.DateField(initial=datetime.date.today)
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>>> print(DateForm())
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<tr><th>Day:</th><td><input type="text" name="day" value="12/23/2008" /><td></tr>
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The callable will be evaluated only when the unbound form is displayed, not when it is defined.
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``widget``
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~~~~~~~~~~
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.. attribute:: Field.widget
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The ``widget`` argument lets you specify a ``Widget`` class to use when
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rendering this ``Field``. See :doc:`/ref/forms/widgets` for more information.
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``help_text``
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~~~~~~~~~~~~~
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.. attribute:: Field.help_text
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The ``help_text`` argument lets you specify descriptive text for this
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``Field``. If you provide ``help_text``, it will be displayed next to the
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``Field`` when the ``Field`` is rendered by one of the convenience ``Form``
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methods (e.g., ``as_ul()``).
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Here's a full example ``Form`` that implements ``help_text`` for two of its
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fields. We've specified ``auto_id=False`` to simplify the output::
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>>> class HelpTextContactForm(forms.Form):
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... subject = forms.CharField(max_length=100, help_text='100 characters max.')
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... message = forms.CharField()
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... sender = forms.EmailField(help_text='A valid email address, please.')
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... cc_myself = forms.BooleanField(required=False)
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>>> f = HelpTextContactForm(auto_id=False)
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>>> print(f.as_table())
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<tr><th>Subject:</th><td><input type="text" name="subject" maxlength="100" /><br /><span class="helptext">100 characters max.</span></td></tr>
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<tr><th>Message:</th><td><input type="text" name="message" /></td></tr>
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<tr><th>Sender:</th><td><input type="email" name="sender" /><br />A valid email address, please.</td></tr>
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<tr><th>Cc myself:</th><td><input type="checkbox" name="cc_myself" /></td></tr>
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>>> print(f.as_ul()))
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<li>Subject: <input type="text" name="subject" maxlength="100" /> <span class="helptext">100 characters max.</span></li>
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<li>Message: <input type="text" name="message" /></li>
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<li>Sender: <input type="email" name="sender" /> A valid email address, please.</li>
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<li>Cc myself: <input type="checkbox" name="cc_myself" /></li>
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>>> print(f.as_p())
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<p>Subject: <input type="text" name="subject" maxlength="100" /> <span class="helptext">100 characters max.</span></p>
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<p>Message: <input type="text" name="message" /></p>
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<p>Sender: <input type="email" name="sender" /> A valid email address, please.</p>
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<p>Cc myself: <input type="checkbox" name="cc_myself" /></p>
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``error_messages``
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~~~~~~~~~~~~~~~~~~
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.. attribute:: Field.error_messages
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The ``error_messages`` argument lets you override the default messages that the
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field will raise. Pass in a dictionary with keys matching the error messages you
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want to override. For example, here is the default error message::
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>>> generic = forms.CharField()
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>>> generic.clean('')
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Traceback (most recent call last):
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...
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ValidationError: [u'This field is required.']
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And here is a custom error message::
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>>> name = forms.CharField(error_messages={'required': 'Please enter your name'})
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>>> name.clean('')
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Traceback (most recent call last):
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...
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ValidationError: [u'Please enter your name']
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In the `built-in Field classes`_ section below, each ``Field`` defines the
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error message keys it uses.
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``validators``
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~~~~~~~~~~~~~~
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.. attribute:: Field.validators
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The ``validators`` argument lets you provide a list of validation functions
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for this field.
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See the :doc:`validators documentation </ref/validators>` for more information.
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``localize``
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~~~~~~~~~~~~
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.. attribute:: Field.localize
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The ``localize`` argument enables the localization of form data, input as well
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as the rendered output.
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See the :ref:`format localization <format-localization>` documentation for
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more information.
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.. _built-in fields:
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Built-in ``Field`` classes
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--------------------------
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Naturally, the ``forms`` library comes with a set of ``Field`` classes that
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represent common validation needs. This section documents each built-in field.
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For each field, we describe the default widget used if you don't specify
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``widget``. We also specify the value returned when you provide an empty value
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(see the section on ``required`` above to understand what that means).
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``BooleanField``
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~~~~~~~~~~~~~~~~
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.. class:: BooleanField(**kwargs)
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* Default widget: :class:`CheckboxInput`
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* Empty value: ``False``
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* Normalizes to: A Python ``True`` or ``False`` value.
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* Validates that the value is ``True`` (e.g. the check box is checked) if
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the field has ``required=True``.
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* Error message keys: ``required``
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.. note::
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Since all ``Field`` subclasses have ``required=True`` by default, the
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validation condition here is important. If you want to include a boolean
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in your form that can be either ``True`` or ``False`` (e.g. a checked or
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unchecked checkbox), you must remember to pass in ``required=False`` when
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creating the ``BooleanField``.
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``CharField``
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~~~~~~~~~~~~~
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.. class:: CharField(**kwargs)
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* Default widget: :class:`TextInput`
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* Empty value: ``''`` (an empty string)
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* Normalizes to: A Unicode object.
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* Validates ``max_length`` or ``min_length``, if they are provided.
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Otherwise, all inputs are valid.
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* Error message keys: ``required``, ``max_length``, ``min_length``
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Has two optional arguments for validation:
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.. attribute:: max_length
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.. attribute:: min_length
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If provided, these arguments ensure that the string is at most or at least
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the given length.
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``ChoiceField``
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~~~~~~~~~~~~~~~
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.. class:: ChoiceField(**kwargs)
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* Default widget: :class:`Select`
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* Empty value: ``''`` (an empty string)
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* Normalizes to: A Unicode object.
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* Validates that the given value exists in the list of choices.
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* Error message keys: ``required``, ``invalid_choice``
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The ``invalid_choice`` error message may contain ``%(value)s``, which will be
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replaced with the selected choice.
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Takes one extra required argument:
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.. attribute:: choices
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An iterable (e.g., a list or tuple) of 2-tuples to use as choices for this
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field. This argument accepts the same formats as the ``choices`` argument
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to a model field. See the :ref:`model field reference documentation on
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choices <field-choices>` for more details.
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``TypedChoiceField``
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~~~~~~~~~~~~~~~~~~~~
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.. class:: TypedChoiceField(**kwargs)
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Just like a :class:`ChoiceField`, except :class:`TypedChoiceField` takes two
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extra arguments, ``coerce`` and ``empty_value``.
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* Default widget: :class:`Select`
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* Empty value: Whatever you've given as ``empty_value``
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* Normalizes to: A value of the type provided by the ``coerce`` argument.
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* Validates that the given value exists in the list of choices and can be
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coerced.
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* Error message keys: ``required``, ``invalid_choice``
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Takes extra arguments:
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.. attribute:: coerce
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A function that takes one argument and returns a coerced value. Examples
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include the built-in ``int``, ``float``, ``bool`` and other types. Defaults
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to an identity function.
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.. attribute:: empty_value
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The value to use to represent "empty." Defaults to the empty string;
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``None`` is another common choice here. Note that this value will not be
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coerced by the function given in the ``coerce`` argument, so choose it
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accordingly.
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``DateField``
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~~~~~~~~~~~~~
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.. class:: DateField(**kwargs)
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* Default widget: :class:`DateInput`
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* Empty value: ``None``
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* Normalizes to: A Python ``datetime.date`` object.
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* Validates that the given value is either a ``datetime.date``,
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``datetime.datetime`` or string formatted in a particular date format.
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* Error message keys: ``required``, ``invalid``
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Takes one optional argument:
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.. attribute:: input_formats
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A list of formats used to attempt to convert a string to a valid
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``datetime.date`` object.
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If no ``input_formats`` argument is provided, the default input formats are::
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'%Y-%m-%d', # '2006-10-25'
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'%m/%d/%Y', # '10/25/2006'
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'%m/%d/%y', # '10/25/06'
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Additionally, if you specify :setting:`USE_L10N=False<USE_L10N>` in your settings, the
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following will also be included in the default input formats::
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'%b %d %Y', # 'Oct 25 2006'
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'%b %d, %Y', # 'Oct 25, 2006'
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'%d %b %Y', # '25 Oct 2006'
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'%d %b, %Y', # '25 Oct, 2006'
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'%B %d %Y', # 'October 25 2006'
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'%B %d, %Y', # 'October 25, 2006'
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'%d %B %Y', # '25 October 2006'
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'%d %B, %Y', # '25 October, 2006'
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See also :ref:`format localization <format-localization>`.
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``DateTimeField``
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~~~~~~~~~~~~~~~~~
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.. class:: DateTimeField(**kwargs)
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* Default widget: :class:`DateTimeInput`
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* Empty value: ``None``
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* Normalizes to: A Python ``datetime.datetime`` object.
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* Validates that the given value is either a ``datetime.datetime``,
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``datetime.date`` or string formatted in a particular datetime format.
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* Error message keys: ``required``, ``invalid``
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Takes one optional argument:
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.. attribute:: input_formats
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A list of formats used to attempt to convert a string to a valid
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``datetime.datetime`` object.
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If no ``input_formats`` argument is provided, the default input formats are::
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'%Y-%m-%d %H:%M:%S', # '2006-10-25 14:30:59'
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'%Y-%m-%d %H:%M', # '2006-10-25 14:30'
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'%Y-%m-%d', # '2006-10-25'
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'%m/%d/%Y %H:%M:%S', # '10/25/2006 14:30:59'
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'%m/%d/%Y %H:%M', # '10/25/2006 14:30'
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'%m/%d/%Y', # '10/25/2006'
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'%m/%d/%y %H:%M:%S', # '10/25/06 14:30:59'
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'%m/%d/%y %H:%M', # '10/25/06 14:30'
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'%m/%d/%y', # '10/25/06'
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See also :ref:`format localization <format-localization>`.
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``DecimalField``
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~~~~~~~~~~~~~~~~
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.. class:: DecimalField(**kwargs)
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* Default widget: :class:`NumberInput` when :attr:`Field.localize` is
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``False``, else :class:`TextInput`.
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* Empty value: ``None``
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* Normalizes to: A Python ``decimal``.
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* Validates that the given value is a decimal. Leading and trailing
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whitespace is ignored.
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* Error message keys: ``required``, ``invalid``, ``max_value``,
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``min_value``, ``max_digits``, ``max_decimal_places``,
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``max_whole_digits``
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The ``max_value`` and ``min_value`` error messages may contain
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``%(limit_value)s``, which will be substituted by the appropriate limit.
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Takes four optional arguments:
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.. attribute:: max_value
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.. attribute:: min_value
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These control the range of values permitted in the field, and should be
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given as ``decimal.Decimal`` values.
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.. attribute:: max_digits
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The maximum number of digits (those before the decimal point plus those
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after the decimal point, with leading zeros stripped) permitted in the
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value.
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.. attribute:: decimal_places
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The maximum number of decimal places permitted.
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``EmailField``
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~~~~~~~~~~~~~~
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.. class:: EmailField(**kwargs)
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* Default widget: :class:`EmailInput`
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* Empty value: ``''`` (an empty string)
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* Normalizes to: A Unicode object.
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* Validates that the given value is a valid email address, using a
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moderately complex regular expression.
|
|
* Error message keys: ``required``, ``invalid``
|
|
|
|
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.
|
|
|
|
``FileField``
|
|
~~~~~~~~~~~~~
|
|
|
|
.. class:: FileField(**kwargs)
|
|
|
|
* Default widget: :class:`ClearableFileInput`
|
|
* Empty value: ``None``
|
|
* Normalizes to: An ``UploadedFile`` object that wraps the file content
|
|
and file name into a single object.
|
|
* Can validate that non-empty file data has been bound to the form.
|
|
* Error message keys: ``required``, ``invalid``, ``missing``, ``empty``,
|
|
``max_length``
|
|
|
|
Has two optional arguments for validation, ``max_length`` and
|
|
``allow_empty_file``. If provided, these ensure that the file name is at
|
|
most the given length, and that validation will succeed even if the file
|
|
content is empty.
|
|
|
|
To learn more about the ``UploadedFile`` object, see the :doc:`file uploads
|
|
documentation </topics/http/file-uploads>`.
|
|
|
|
When you use a ``FileField`` in a form, you must also remember to
|
|
:ref:`bind the file data to the form <binding-uploaded-files>`.
|
|
|
|
The ``max_length`` error refers to the length of the filename. In the error
|
|
message for that key, ``%(max)d`` will be replaced with the maximum filename
|
|
length and ``%(length)d`` will be replaced with the current filename length.
|
|
|
|
``FilePathField``
|
|
~~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: FilePathField(**kwargs)
|
|
|
|
* Default widget: :class:`Select`
|
|
* Empty value: ``None``
|
|
* Normalizes to: A unicode object
|
|
* Validates that the selected choice exists in the list of choices.
|
|
* Error message keys: ``required``, ``invalid_choice``
|
|
|
|
The field allows choosing from files inside a certain directory. It takes three
|
|
extra arguments; only ``path`` is required:
|
|
|
|
.. attribute:: path
|
|
|
|
The absolute path to the directory whose contents you want listed. This
|
|
directory must exist.
|
|
|
|
.. attribute:: recursive
|
|
|
|
If ``False`` (the default) only the direct contents of ``path`` will be
|
|
offered as choices. If ``True``, the directory will be descended into
|
|
recursively and all descendants will be listed as choices.
|
|
|
|
.. attribute:: match
|
|
|
|
A regular expression pattern; only files with names matching this expression
|
|
will be allowed as choices.
|
|
|
|
.. attribute:: allow_files
|
|
|
|
.. versionadded:: 1.5
|
|
|
|
Optional. Either ``True`` or ``False``. Default is ``True``. Specifies
|
|
whether files in the specified location should be included. Either this or
|
|
:attr:`allow_folders` must be ``True``.
|
|
|
|
.. attribute:: allow_folders
|
|
|
|
.. versionadded:: 1.5
|
|
|
|
Optional. Either ``True`` or ``False``. Default is ``False``. Specifies
|
|
whether folders in the specified location should be included. Either this or
|
|
:attr:`allow_files` must be ``True``.
|
|
|
|
|
|
``FloatField``
|
|
~~~~~~~~~~~~~~
|
|
|
|
.. class:: FloatField(**kwargs)
|
|
|
|
* Default widget: :class:`NumberInput` when :attr:`Field.localize` is
|
|
``False``, else :class:`TextInput`.
|
|
* Empty value: ``None``
|
|
* Normalizes to: A Python float.
|
|
* Validates that the given value is an float. Leading and trailing
|
|
whitespace is allowed, as in Python's ``float()`` function.
|
|
* Error message keys: ``required``, ``invalid``, ``max_value``,
|
|
``min_value``
|
|
|
|
Takes two optional arguments for validation, ``max_value`` and ``min_value``.
|
|
These control the range of values permitted in the field.
|
|
|
|
``ImageField``
|
|
~~~~~~~~~~~~~~
|
|
|
|
.. class:: ImageField(**kwargs)
|
|
|
|
* Default widget: :class:`ClearableFileInput`
|
|
* Empty value: ``None``
|
|
* Normalizes to: An ``UploadedFile`` object that wraps the file content
|
|
and file name into a single object.
|
|
* Validates that file data has been bound to the form, and that the
|
|
file is of an image format understood by PIL.
|
|
* Error message keys: ``required``, ``invalid``, ``missing``, ``empty``,
|
|
``invalid_image``
|
|
|
|
Using an ``ImageField`` requires that the `Python Imaging Library`_ (PIL)
|
|
is installed and supports the image formats you use. If you encounter a
|
|
``corrupt image`` error when you upload an image, it usually means PIL
|
|
doesn't understand its format. To fix this, install the appropriate
|
|
library and reinstall PIL.
|
|
|
|
When you use an ``ImageField`` on a form, you must also remember to
|
|
:ref:`bind the file data to the form <binding-uploaded-files>`.
|
|
|
|
.. _Python Imaging Library: http://www.pythonware.com/products/pil/
|
|
|
|
``IntegerField``
|
|
~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: IntegerField(**kwargs)
|
|
|
|
* Default widget: :class:`NumberInput` when :attr:`Field.localize` is
|
|
``False``, else :class:`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.
|
|
* Error message keys: ``required``, ``invalid``, ``max_value``,
|
|
``min_value``
|
|
|
|
The ``max_value`` and ``min_value`` error messages may contain
|
|
``%(limit_value)s``, which will be substituted by the appropriate limit.
|
|
|
|
Takes two optional arguments for validation:
|
|
|
|
.. attribute:: max_value
|
|
.. attribute:: min_value
|
|
|
|
These control the range of values permitted in the field.
|
|
|
|
``IPAddressField``
|
|
~~~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: IPAddressField(**kwargs)
|
|
|
|
* Default widget: :class:`TextInput`
|
|
* Empty value: ``''`` (an empty string)
|
|
* Normalizes to: A Unicode object.
|
|
* Validates that the given value is a valid IPv4 address, using a regular
|
|
expression.
|
|
* Error message keys: ``required``, ``invalid``
|
|
|
|
``GenericIPAddressField``
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: GenericIPAddressField(**kwargs)
|
|
|
|
A field containing either an IPv4 or an IPv6 address.
|
|
|
|
* Default widget: :class:`TextInput`
|
|
* Empty value: ``''`` (an empty string)
|
|
* Normalizes to: A Unicode object. IPv6 addresses are
|
|
normalized as described below.
|
|
* Validates that the given value is a valid IP address.
|
|
* Error message keys: ``required``, ``invalid``
|
|
|
|
The IPv6 address normalization follows :rfc:`4291#section-2.2` section 2.2,
|
|
including using the IPv4 format suggested in paragraph 3 of that section, like
|
|
``::ffff:192.0.2.0``. For example, ``2001:0::0:01`` would be normalized to
|
|
``2001::1``, and ``::ffff:0a0a:0a0a`` to ``::ffff:10.10.10.10``. All characters
|
|
are converted to lowercase.
|
|
|
|
Takes two optional arguments:
|
|
|
|
.. attribute:: protocol
|
|
|
|
Limits valid inputs to the specified protocol.
|
|
Accepted values are ``both`` (default), ``IPv4``
|
|
or ``IPv6``. Matching is case insensitive.
|
|
|
|
.. attribute:: unpack_ipv4
|
|
|
|
Unpacks IPv4 mapped addresses like ``::ffff:192.0.2.1``.
|
|
If this option is enabled that address would be unpacked to
|
|
``192.0.2.1``. Default is disabled. Can only be used
|
|
when ``protocol`` is set to ``'both'``.
|
|
|
|
``MultipleChoiceField``
|
|
~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: MultipleChoiceField(**kwargs)
|
|
|
|
* Default widget: :class:`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.
|
|
* Error message keys: ``required``, ``invalid_choice``, ``invalid_list``
|
|
|
|
The ``invalid_choice`` error message may contain ``%(value)s``, which will be
|
|
replaced with the selected choice.
|
|
|
|
Takes one extra required argument, ``choices``, as for ``ChoiceField``.
|
|
|
|
``TypedMultipleChoiceField``
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: TypedMultipleChoiceField(**kwargs)
|
|
|
|
Just like a :class:`MultipleChoiceField`, except :class:`TypedMultipleChoiceField`
|
|
takes two extra arguments, ``coerce`` and ``empty_value``.
|
|
|
|
* Default widget: :class:`SelectMultiple`
|
|
* Empty value: Whatever you've given as ``empty_value``
|
|
* Normalizes to: A list of values of the type provided by the ``coerce``
|
|
argument.
|
|
* Validates that the given values exists in the list of choices and can be
|
|
coerced.
|
|
* Error message keys: ``required``, ``invalid_choice``
|
|
|
|
The ``invalid_choice`` error message may contain ``%(value)s``, which will be
|
|
replaced with the selected choice.
|
|
|
|
Takes two extra arguments, ``coerce`` and ``empty_value``, as for ``TypedChoiceField``.
|
|
|
|
``NullBooleanField``
|
|
~~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: NullBooleanField(**kwargs)
|
|
|
|
* Default widget: :class:`NullBooleanSelect`
|
|
* Empty value: ``None``
|
|
* Normalizes to: A Python ``True``, ``False`` or ``None`` value.
|
|
* Validates nothing (i.e., it never raises a ``ValidationError``).
|
|
|
|
``RegexField``
|
|
~~~~~~~~~~~~~~
|
|
|
|
.. class:: RegexField(**kwargs)
|
|
|
|
* Default widget: :class:`TextInput`
|
|
* Empty value: ``''`` (an empty string)
|
|
* Normalizes to: A Unicode object.
|
|
* Validates that the given value matches against a certain regular
|
|
expression.
|
|
* Error message keys: ``required``, ``invalid``
|
|
|
|
Takes one required argument:
|
|
|
|
.. attribute:: regex
|
|
|
|
A regular expression specified either as a string or a compiled regular
|
|
expression object.
|
|
|
|
Also takes ``max_length`` and ``min_length``, which work just as they do for
|
|
``CharField``.
|
|
|
|
The optional argument ``error_message`` is also accepted for backwards
|
|
compatibility. The preferred way to provide an error message is to use the
|
|
``error_messages`` argument, passing a dictionary with ``'invalid'`` as a key
|
|
and the error message as the value.
|
|
|
|
``SlugField``
|
|
~~~~~~~~~~~~~
|
|
|
|
.. class:: SlugField(**kwargs)
|
|
|
|
* Default widget: :class:`TextInput`
|
|
* Empty value: ``''`` (an empty string)
|
|
* Normalizes to: A Unicode object.
|
|
* Validates that the given value contains only letters, numbers,
|
|
underscores, and hyphens.
|
|
* Error messages: ``required``, ``invalid``
|
|
|
|
This field is intended for use in representing a model
|
|
:class:`~django.db.models.SlugField` in forms.
|
|
|
|
``TimeField``
|
|
~~~~~~~~~~~~~
|
|
|
|
.. class:: TimeField(**kwargs)
|
|
|
|
* Default widget: :class:`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.
|
|
* Error message keys: ``required``, ``invalid``
|
|
|
|
Takes one optional argument:
|
|
|
|
.. attribute:: input_formats
|
|
|
|
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``
|
|
~~~~~~~~~~~~
|
|
|
|
.. class:: URLField(**kwargs)
|
|
|
|
* Default widget: :class:`URLInput`
|
|
* Empty value: ``''`` (an empty string)
|
|
* Normalizes to: A Unicode object.
|
|
* Validates that the given value is a valid URL.
|
|
* Error message keys: ``required``, ``invalid``
|
|
|
|
Takes the following optional arguments:
|
|
|
|
.. attribute:: max_length
|
|
.. attribute:: min_length
|
|
|
|
These are the same as ``CharField.max_length`` and ``CharField.min_length``.
|
|
|
|
|
|
Slightly complex built-in ``Field`` classes
|
|
-------------------------------------------
|
|
|
|
``ComboField``
|
|
~~~~~~~~~~~~~~
|
|
|
|
.. class:: ComboField(**kwargs)
|
|
|
|
* Default widget: :class:`TextInput`
|
|
* Empty value: ``''`` (an empty string)
|
|
* Normalizes to: A Unicode object.
|
|
* Validates that the given value against each of the fields specified
|
|
as an argument to the ``ComboField``.
|
|
* Error message keys: ``required``, ``invalid``
|
|
|
|
Takes one extra required argument:
|
|
|
|
.. attribute:: fields
|
|
|
|
The list of fields that should be used to validate the field's value (in
|
|
the order in which they are provided).
|
|
|
|
>>> f = ComboField(fields=[CharField(max_length=20), EmailField()])
|
|
>>> f.clean('test@example.com')
|
|
u'test@example.com'
|
|
>>> f.clean('longemailaddress@example.com')
|
|
Traceback (most recent call last):
|
|
...
|
|
ValidationError: [u'Ensure this value has at most 20 characters (it has 28).']
|
|
|
|
``MultiValueField``
|
|
~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: MultiValueField(fields=(), **kwargs)
|
|
|
|
* Default widget: :class:`TextInput`
|
|
* Empty value: ``''`` (an empty string)
|
|
* Normalizes to: the type returned by the ``compress`` method of the subclass.
|
|
* Validates that the given value against each of the fields specified
|
|
as an argument to the ``MultiValueField``.
|
|
* Error message keys: ``required``, ``invalid``
|
|
|
|
Aggregates the logic of multiple fields that together produce a single
|
|
value.
|
|
|
|
This field is abstract and must be subclassed. In contrast with the
|
|
single-value fields, subclasses of :class:`MultiValueField` must not
|
|
implement :meth:`~django.forms.Field.clean` but instead - implement
|
|
:meth:`~MultiValueField.compress`.
|
|
|
|
Takes one extra required argument:
|
|
|
|
.. attribute:: fields
|
|
|
|
A tuple of fields whose values are cleaned and subsequently combined
|
|
into a single value. Each value of the field is cleaned by the
|
|
corresponding field in ``fields`` -- the first value is cleaned by the
|
|
first field, the second value is cleaned by the second field, etc.
|
|
Once all fields are cleaned, the list of clean values is combined into
|
|
a single value by :meth:`~MultiValueField.compress`.
|
|
|
|
.. attribute:: MultiValueField.widget
|
|
|
|
Must be a subclass of :class:`django.forms.MultiWidget`.
|
|
Default value is :class:`~django.forms.TextInput`, which
|
|
probably is not very useful in this case.
|
|
|
|
.. method:: compress(data_list)
|
|
|
|
Takes a list of valid values and returns a "compressed" version of
|
|
those values -- in a single value. For example,
|
|
:class:`SplitDateTimeField` is a subclass which combines a time field
|
|
and a date field into a ``datetime`` object.
|
|
|
|
This method must be implemented in the subclasses.
|
|
|
|
``SplitDateTimeField``
|
|
~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: SplitDateTimeField(**kwargs)
|
|
|
|
* Default widget: :class:`SplitDateTimeWidget`
|
|
* Empty value: ``None``
|
|
* Normalizes to: A Python ``datetime.datetime`` object.
|
|
* Validates that the given value is a ``datetime.datetime`` or string
|
|
formatted in a particular datetime format.
|
|
* Error message keys: ``required``, ``invalid``, ``invalid_date``,
|
|
``invalid_time``
|
|
|
|
Takes two optional arguments:
|
|
|
|
.. attribute:: input_date_formats
|
|
|
|
A list of formats used to attempt to convert a string to a valid
|
|
``datetime.date`` object.
|
|
|
|
If no ``input_date_formats`` argument is provided, the default input formats
|
|
for ``DateField`` are used.
|
|
|
|
.. attribute:: input_time_formats
|
|
|
|
A list of formats used to attempt to convert a string to a valid
|
|
``datetime.time`` object.
|
|
|
|
If no ``input_time_formats`` argument is provided, the default input formats
|
|
for ``TimeField`` are used.
|
|
|
|
Fields which handle relationships
|
|
---------------------------------
|
|
|
|
Two fields are available for representing relationships between
|
|
models: :class:`ModelChoiceField` and
|
|
:class:`ModelMultipleChoiceField`. Both of these fields require a
|
|
single ``queryset`` parameter that is used to create the choices for
|
|
the field. Upon form validation, these fields will place either one
|
|
model object (in the case of ``ModelChoiceField``) or multiple model
|
|
objects (in the case of ``ModelMultipleChoiceField``) into the
|
|
``cleaned_data`` dictionary of the form.
|
|
|
|
``ModelChoiceField``
|
|
~~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: ModelChoiceField(**kwargs)
|
|
|
|
* Default widget: :class:`Select`
|
|
* Empty value: ``None``
|
|
* Normalizes to: A model instance.
|
|
* Validates that the given id exists in the queryset.
|
|
* Error message keys: ``required``, ``invalid_choice``
|
|
|
|
Allows the selection of a single model object, suitable for representing a
|
|
foreign key. Note that the default widget for ``ModelChoiceField`` becomes
|
|
impractical when the number of entries increases. You should avoid using it
|
|
for more than 100 items.
|
|
|
|
A single argument is required:
|
|
|
|
.. attribute:: queryset
|
|
|
|
A ``QuerySet`` of model objects from which the choices for the
|
|
field will be derived, and which will be used to validate the
|
|
user's selection.
|
|
|
|
``ModelChoiceField`` also takes one optional argument:
|
|
|
|
.. attribute:: empty_label
|
|
|
|
By default the ``<select>`` widget used by ``ModelChoiceField`` will have an
|
|
empty choice at the top of the list. You can change the text of this
|
|
label (which is ``"---------"`` by default) with the ``empty_label``
|
|
attribute, or you can disable the empty label entirely by setting
|
|
``empty_label`` to ``None``::
|
|
|
|
# A custom empty label
|
|
field1 = forms.ModelChoiceField(queryset=..., empty_label="(Nothing)")
|
|
|
|
# No empty label
|
|
field2 = forms.ModelChoiceField(queryset=..., empty_label=None)
|
|
|
|
Note that if a ``ModelChoiceField`` is required and has a default
|
|
initial value, no empty choice is created (regardless of the value
|
|
of ``empty_label``).
|
|
|
|
The ``__unicode__`` method of the model will be called to generate
|
|
string representations of the objects for use in the field's choices;
|
|
to provide customized representations, subclass ``ModelChoiceField``
|
|
and override ``label_from_instance``. This method will receive a model
|
|
object, and should return a string suitable for representing it. For
|
|
example::
|
|
|
|
class MyModelChoiceField(ModelChoiceField):
|
|
def label_from_instance(self, obj):
|
|
return "My Object #%i" % obj.id
|
|
|
|
``ModelMultipleChoiceField``
|
|
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
|
|
|
|
.. class:: ModelMultipleChoiceField(**kwargs)
|
|
|
|
* Default widget: :class:`SelectMultiple`
|
|
* Empty value: An empty ``QuerySet`` (self.queryset.none())
|
|
* Normalizes to: A ``QuerySet`` of model instances.
|
|
* Validates that every id in the given list of values exists in the
|
|
queryset.
|
|
* Error message keys: ``required``, ``list``, ``invalid_choice``,
|
|
``invalid_pk_value``
|
|
|
|
.. versionchanged:: 1.5
|
|
The empty and normalized values were changed to be consistently
|
|
``QuerySets`` instead of ``[]`` and ``QuerySet`` respectively.
|
|
|
|
Allows the selection of one or more model objects, suitable for
|
|
representing a many-to-many relation. As with :class:`ModelChoiceField`,
|
|
you can use ``label_from_instance`` to customize the object
|
|
representations, and ``queryset`` is a required parameter:
|
|
|
|
.. attribute:: queryset
|
|
|
|
A ``QuerySet`` of model objects from which the choices for the
|
|
field will be derived, and which will be used to validate the
|
|
user's selection.
|
|
|
|
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.forms.Field``. Its only requirements are that it implement a
|
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``clean()`` method and that its ``__init__()`` method accept the core arguments
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mentioned above (``required``, ``label``, ``initial``, ``widget``,
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``help_text``).
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