======= Widgets ======= .. module:: django.forms.widgets :synopsis: Django's built-in form widgets. .. currentmodule:: django.forms A widget is Django's representation of a HTML input element. The widget handles the rendering of the HTML, and the extraction of data from a GET/POST dictionary that corresponds to the widget. Specifying widgets ------------------ Whenever you specify a field on a form, Django will use a default widget that is appropriate to the type of data that is to be displayed. To find which widget is used on which field, see the documentation about :ref:`built-in fields`. However, if you want to use a different widget for a field, you can just use the :attr:`~Field.widget` argument on the field definition. For example:: from django import forms class CommentForm(forms.Form): name = forms.CharField() url = forms.URLField() comment = forms.CharField(widget=forms.Textarea) This would specify a form with a comment that uses a larger :class:`Textarea` widget, rather than the default :class:`TextInput` widget. Setting arguments for widgets ----------------------------- Many widgets have optional extra arguments; they can be set when defining the widget on the field. In the following example, the :attr:`~SelectDateWidget.years` attribute is set for a :class:`~django.forms.extras.widgets.SelectDateWidget`:: from django.forms.fields import DateField, ChoiceField, MultipleChoiceField from django.forms.widgets import RadioSelect, CheckboxSelectMultiple from django.forms.extras.widgets import SelectDateWidget BIRTH_YEAR_CHOICES = ('1980', '1981', '1982') GENDER_CHOICES = (('m', 'Male'), ('f', 'Female')) FAVORITE_COLORS_CHOICES = (('blue', 'Blue'), ('green', 'Green'), ('black', 'Black')) class SimpleForm(forms.Form): birth_year = DateField(widget=SelectDateWidget(years=BIRTH_YEAR_CHOICES)) gender = ChoiceField(widget=RadioSelect, choices=GENDER_CHOICES) favorite_colors = forms.MultipleChoiceField(required=False, widget=CheckboxSelectMultiple, choices=FAVORITE_COLORS_CHOICES) See the :ref:`built-in widgets` for more information about which widgets are available and which arguments they accept. Widgets inheriting from the Select widget ----------------------------------------- Widgets inheriting from the :class:`Select` widget deal with choices. They present the user with a list of options to choose from. The different widgets present this choice differently; the :class:`Select` widget itself uses a ``<select>`` HTML list representation, while :class:`RadioSelect` uses radio buttons. :class:`Select` widgets are used by default on :class:`ChoiceField` fields. The choices displayed on the widget are inherited from the :class:`ChoiceField` and changing :attr:`ChoiceField.choices` will update :attr:`Select.choices`. For example:: >>> from django import forms >>> CHOICES = (('1', 'First',), ('2', 'Second',))) >>> choice_field = forms.ChoiceField(widget=forms.RadioSelect, choices=CHOICES) >>> choice_field.choices [('1', 'First'), ('2', 'Second')] >>> choice_field.widget.choices [('1', 'First'), ('2', 'Second')] >>> choice_field.widget.choices = () >>> choice_field.choices = (('1', 'First and only',),) >>> choice_field.widget.choices [('1', 'First and only')] Widgets which offer a :attr:`~Select.choices` attribute can however be used with fields which are not based on choice -- such as a :class:`CharField` -- but it is recommended to use a :class:`ChoiceField`-based field when the choices are inherent to the model and not just the representational widget. Customizing widget instances ---------------------------- When Django renders a widget as HTML, it only renders the bare minimum HTML - Django doesn't add a class definition, or any other widget-specific attributes. This means that all :class:`TextInput` widgets will appear the same on your Web page. If you want to make one widget look different to another, you need to specify additional attributes for each widget. When you specify a widget, you can provide a list of attributes that will be added to the rendered HTML for the widget. For example, take the following simple form:: from django import forms class CommentForm(forms.Form): name = forms.CharField() url = forms.URLField() comment = forms.CharField() This form will include three default :class:`TextInput` widgets, with default rendering -- no CSS class, no extra attributes. This means that the input boxes provided for each widget will be rendered exactly the same:: >>> f = CommentForm(auto_id=False) >>> f.as_table() <tr><th>Name:</th><td><input type="text" name="name" /></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> On a real Web page, you probably don't want every widget to look the same. You might want a larger input element for the comment, and you might want the 'name' widget to have some special CSS class. To do this, you use the :attr:`Widget.attrs` argument when creating the widget: For example:: class CommentForm(forms.Form): name = forms.CharField( widget=forms.TextInput(attrs={'class':'special'})) url = forms.URLField() comment = forms.CharField( widget=forms.TextInput(attrs={'size':'40'})) Django will then include the extra attributes in the rendered output: >>> f = CommentForm(auto_id=False) >>> f.as_table() <tr><th>Name:</th><td><input type="text" name="name" class="special"/></td></tr> <tr><th>Url:</th><td><input type="text" name="url"/></td></tr> <tr><th>Comment:</th><td><input type="text" name="comment" size="40"/></td></tr> .. _built-in widgets: Built-in widgets ---------------- Django provides a representation of all the basic HTML widgets, plus some commonly used groups of widgets: ``Widget`` ~~~~~~~~~~ .. class:: Widget This abstract class cannot be rendered, but provides the basic attribute :attr:`~Widget.attrs`. .. attribute:: Widget.attrs A dictionary containing HTML attributes to be set on the rendered widget. .. code-block:: python >>> name = forms.TextInput(attrs={'size': 10, 'title': 'Your name',}) >>> name.render('name', 'A name') u'<input title="Your name" type="text" name="name" value="A name" size="10" />' ``TextInput`` ~~~~~~~~~~~~~ .. class:: TextInput Text input: ``<input type='text' ...>`` ``PasswordInput`` ~~~~~~~~~~~~~~~~~ .. class:: PasswordInput Password input: ``<input type='password' ...>`` Takes one optional argument: .. attribute:: PasswordInput.render_value Determines whether the widget will have a value filled in when the form is re-displayed after a validation error (default is ``False``). .. versionchanged:: 1.3 The default value for :attr:`~PasswordInput.render_value` was changed from ``True`` to ``False`` ``HiddenInput`` ~~~~~~~~~~~~~~~ .. class:: HiddenInput Hidden input: ``<input type='hidden' ...>`` ``MultipleHiddenInput`` ~~~~~~~~~~~~~~~~~~~~~~~ .. class:: MultipleHiddenInput Multiple ``<input type='hidden' ...>`` widgets. A widget that handles multiple hidden widgets for fields that have a list of values. .. attribute:: MultipleHiddenInput.choices This attribute is optional when the field does not have a :attr:`~Field.choices` attribute. If it does, it will override anything you set here when the attribute is updated on the :class:`Field`. ``FileInput`` ~~~~~~~~~~~~~ .. class:: FileInput File upload input: ``<input type='file' ...>`` ``ClearableFileInput`` ~~~~~~~~~~~~~~~~~~~~~~ .. class:: ClearableFileInput .. versionadded:: 1.3 File upload input: ``<input type='file' ...>``, with an additional checkbox input to clear the field's value, if the field is not required and has initial data. ``DateInput`` ~~~~~~~~~~~~~ .. class:: DateInput Date input as a simple text box: ``<input type='text' ...>`` Takes one optional argument: .. attribute:: DateInput.format The format in which this field's initial value will be displayed. If no ``format`` argument is provided, the default format is the first format found in :setting:`DATE_INPUT_FORMATS` and respects :ref:`format-localization`. ``DateTimeInput`` ~~~~~~~~~~~~~~~~~ .. class:: DateTimeInput Date/time input as a simple text box: ``<input type='text' ...>`` Takes one optional argument: .. attribute:: DateTimeInput.format The format in which this field's initial value will be displayed. If no ``format`` argument is provided, the default format is the first format found in :setting:`DATETIME_INPUT_FORMATS` and respects :ref:`format-localization`. ``TimeInput`` ~~~~~~~~~~~~~ .. class:: TimeInput Time input as a simple text box: ``<input type='text' ...>`` Takes one optional argument: .. attribute:: TimeInput.format The format in which this field's initial value will be displayed. If no ``format`` argument is provided, the default format is the first format found in :setting:`TIME_INPUT_FORMATS` and respects :ref:`format-localization`. ``Textarea`` ~~~~~~~~~~~~ .. class:: Textarea Text area: ``<textarea>...</textarea>`` ``CheckboxInput`` ~~~~~~~~~~~~~~~~~ .. class:: CheckboxInput Checkbox: ``<input type='checkbox' ...>`` Takes one optional argument: .. attribute:: CheckboxInput.check_test A callable that takes the value of the CheckBoxInput and returns ``True`` if the checkbox should be checked for that value. ``Select`` ~~~~~~~~~~ .. class:: Select Select widget: ``<select><option ...>...</select>`` .. attribute:: Select.choices This attribute is optional when the field does not have a :attr:`~Field.choices` attribute. If it does, it will override anything you set here when the attribute is updated on the :class:`Field`. ``NullBooleanSelect`` ~~~~~~~~~~~~~~~~~~~~~ .. class:: NullBooleanSelect Select widget with options 'Unknown', 'Yes' and 'No' ``SelectMultiple`` ~~~~~~~~~~~~~~~~~~ .. class:: SelectMultiple Similar to :class:`Select`, but allows multiple selection: ``<select multiple='multiple'>...</select>`` ``RadioSelect`` ~~~~~~~~~~~~~~~ .. class:: RadioSelect Similar to :class:`Select`, but rendered as a list of radio buttons within ``<li>`` tags: .. code-block:: html <ul> <li><input type='radio' ...></li> ... </ul> .. versionadded:: 1.4 For more granular control over the generated markup, you can loop over the radio buttons in the template. Assuming a form ``myform`` with a field ``beatles`` that uses a ``RadioSelect`` as its widget: .. code-block:: html+django {% for radio in myform.beatles %} <div class="myradio"> {{ radio }} </div> {% endfor %} This would generate the following HTML: .. code-block:: html <div class="myradio"> <label><input type="radio" name="beatles" value="john" /> John</label> </div> <div class="myradio"> <label><input type="radio" name="beatles" value="paul" /> Paul</label> </div> <div class="myradio"> <label><input type="radio" name="beatles" value="george" /> George</label> </div> <div class="myradio"> <label><input type="radio" name="beatles" value="ringo" /> Ringo</label> </div> That included the ``<label>`` tags. To get more granular, you can use each radio button's ``tag`` and ``choice_label`` attributes. For example, this template... .. code-block:: html+django {% for radio in myform.beatles %} <label> {{ radio.choice_label }} <span class="radio">{{ radio.tag }}</span> </label> {% endfor %} ...will result in the following HTML: .. code-block:: html <label> John <span class="radio"><input type="radio" name="beatles" value="john" /></span> </label> <label> Paul <span class="radio"><input type="radio" name="beatles" value="paul" /></span> </label> <label> George <span class="radio"><input type="radio" name="beatles" value="george" /></span> </label> <label> Ringo <span class="radio"><input type="radio" name="beatles" value="ringo" /></span> </label> If you decide not to loop over the radio buttons -- e.g., if your template simply includes ``{{ myform.beatles }}`` -- they'll be output in a ``<ul>`` with ``<li>`` tags, as above. ``CheckboxSelectMultiple`` ~~~~~~~~~~~~~~~~~~~~~~~~~~ .. class:: CheckboxSelectMultiple Similar to :class:`SelectMultiple`, but rendered as a list of check buttons: .. code-block:: html <ul> <li><input type='checkbox' ...></li> ... </ul> ``MultiWidget`` ~~~~~~~~~~~~~~~ .. class:: MultiWidget Wrapper around multiple other widgets. You'll probably want to use this class with :class:`MultiValueField`. Its ``render()`` method is different than other widgets', because it has to figure out how to split a single value for display in multiple widgets. Subclasses may implement ``format_output``, which takes the list of rendered widgets and returns a string of HTML that formats them any way you'd like. The ``value`` argument used when rendering can be one of two things: * A ``list``. * A single value (e.g., a string) that is the "compressed" representation of a ``list`` of values. In the second case -- i.e., if the value is *not* a list -- ``render()`` will first decompress the value into a ``list`` before rendering it. It does so by calling the ``decompress()`` method, which :class:`MultiWidget`'s subclasses must implement. This method takes a single "compressed" value and returns a ``list``. An example of this is how :class:`SplitDateTimeWidget` turns a :class:`datetime` value into a list with date and time split into two seperate values:: class SplitDateTimeWidget(MultiWidget): # ... def decompress(self, value): if value: return [value.date(), value.time().replace(microsecond=0)] return [None, None] When ``render()`` executes its HTML rendering, each value in the list is rendered with the corresponding widget -- the first value is rendered in the first widget, the second value is rendered in the second widget, etc. :class:`MultiWidget` has one required argument: .. attribute:: MultiWidget.widgets An iterable containing the widgets needed. ``SplitDateTimeWidget`` ~~~~~~~~~~~~~~~~~~~~~~~ .. class:: SplitDateTimeWidget Wrapper (using :class:`MultiWidget`) around two widgets: :class:`DateInput` for the date, and :class:`TimeInput` for the time. ``SplitDateTimeWidget`` has two optional attributes: .. attribute:: SplitDateTimeWidget.date_format Similar to :attr:`DateInput.format` .. attribute:: SplitDateTimeWidget.time_format Similar to :attr:`TimeInput.format` ``SplitHiddenDateTimeWidget`` ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ .. class:: SplitHiddenDateTimeWidget Similar to :class:`SplitDateTimeWidget`, but uses :class:`HiddenInput` for both date and time. .. currentmodule:: django.forms.extras.widgets ``SelectDateWidget`` ~~~~~~~~~~~~~~~~~~~~ .. class:: SelectDateWidget Wrapper around three :class:`~django.forms.Select` widgets: one each for month, day, and year. Note that this widget lives in a separate file from the standard widgets. Takes one optional argument: .. attribute:: SelectDateWidget.years An optional list/tuple of years to use in the "year" select box. The default is a list containing the current year and the next 9 years.