Widgets
A widget is Django's representation of an HTML input element. The widgethandles the rendering of the HTML, and the extraction of data from a GET/POSTdictionary that corresponds to the widget.
The HTML generated by the built-in widgets uses HTML5 syntax, targeting<!DOCTYPE html>
. For example, it uses boolean attributes such as checked
rather than the XHTML style of checked='checked'
.
Tip
Widgets should not be confused with the form fields.Form fields deal with the logic of input validation and are used directlyin templates. Widgets deal with rendering of HTML form input elements onthe web page and extraction of raw submitted data. However, widgets doneed to be assigned to form fields.
Specifying widgets
Whenever you specify a field on a form, Django will use a default widgetthat is appropriate to the type of data that is to be displayed. To findwhich widget is used on which field, see the documentation aboutBuilt-in Field classes.
However, if you want to use a different widget for a field, you canjust use the widget
argument on the field definition. Forexample:
- 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 Textarea
widget, rather than the default TextInput
widget.
Setting arguments for widgets
Many widgets have optional extra arguments; they can be set when defining thewidget on the field. In the following example, theyears
attribute is set for aSelectDateWidget
:
- from django import forms
- BIRTH_YEAR_CHOICES = ('1980', '1981', '1982')
- FAVORITE_COLORS_CHOICES = (
- ('blue', 'Blue'),
- ('green', 'Green'),
- ('black', 'Black'),
- )
- class SimpleForm(forms.Form):
- birth_year = forms.DateField(widget=forms.SelectDateWidget(years=BIRTH_YEAR_CHOICES))
- favorite_colors = forms.MultipleChoiceField(
- required=False,
- widget=forms.CheckboxSelectMultiple,
- choices=FAVORITE_COLORS_CHOICES,
- )
See the Built-in widgets for more information about which widgetsare available and which arguments they accept.
Widgets inheriting from the Select widget
Widgets inheriting from the Select
widget deal with choices. Theypresent the user with a list of options to choose from. The different widgetspresent this choice differently; the Select
widget itself uses a<select>
HTML list representation, while RadioSelect
uses radiobuttons.
Select
widgets are used by default on ChoiceField
fields. Thechoices displayed on the widget are inherited from the ChoiceField
andchanging ChoiceField.choices
will update Select.choices
. Forexample:
- >>> 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 choices
attribute can however be usedwith fields which are not based on choice — such as a CharField
—but it is recommended to use a ChoiceField
-based field when thechoices are inherent to the model and not just the representational widget.
Customizing widget instances
When Django renders a widget as HTML, it only renders very minimal markup -Django doesn't add class names, or any other widget-specific attributes. Thismeans, for example, that all TextInput
widgets will appear the sameon your Web pages.
There are two ways to customize widgets: per widget instance and per widget class.
Styling widget instances
If you want to make one widget instance look different from another, you willneed to specify additional attributes at the time when the widget object isinstantiated and assigned to a form field (and perhaps add some rules to yourCSS files).
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 TextInput
widgets, with defaultrendering — no CSS class, no extra attributes. This means that the input boxesprovided 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" required /></td></tr>
- <tr><th>Url:</th><td><input type="url" name="url" required /></td></tr>
- <tr><th>Comment:</th><td><input type="text" name="comment" required /></td></tr>
On a real Web page, you probably don't want every widget to look the same. Youmight want a larger input element for the comment, and you might want the'name' widget to have some special CSS class. It is also possible to specifythe 'type' attribute to take advantage of the new HTML5 input types. To dothis, you use the Widget.attrs
argument when creating the widget:
- 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'}))
You can also modify a widget in the form definition:
- class CommentForm(forms.Form):
- name = forms.CharField()
- url = forms.URLField()
- comment = forms.CharField()
- name.widget.attrs.update({'class': 'special'})
- comment.widget.attrs.update(size='40')
Or if the field isn't declared directly on the form (such as model form fields),you can use the Form.fields
attribute:
- class CommentForm(forms.ModelForm):
- def __init__(self, *args, **kwargs):
- super().__init__(*args, **kwargs)
- self.fields['name'].widget.attrs.update({'class': 'special'})
- self.fields['comment'].widget.attrs.update(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" required /></td></tr>
- <tr><th>Url:</th><td><input type="url" name="url" required /></td></tr>
- <tr><th>Comment:</th><td><input type="text" name="comment" size="40" required /></td></tr>
You can also set the HTML id
using attrs
. SeeBoundField.id_for_label
for an example.
Styling widget classes
With widgets, it is possible to add assets (css
and javascript
)and more deeply customize their appearance and behavior.
In a nutshell, you will need to subclass the widget and eitherdefine a "Media" inner class orcreate a "media" property.
These methods involve somewhat advanced Python programming and are described indetail in the Form Assets topic guide.
Base widget classes
Base widget classes Widget
and MultiWidget
are subclassed byall the built-in widgets and may serve as afoundation for custom widgets.
Widget
- class
Widget
(attrs=None)[source] This abstract class cannot be rendered, but provides the basic attribute
attrs
. You may also implement or override therender()
method on custom widgets.
- >>> from django import forms
- >>> name = forms.TextInput(attrs={'size': 10, 'title': 'Your name'})
- >>> name.render('name', 'A name')
- '<input title="Your name" type="text" name="name" value="A name" size="10" />'
If you assign a value of True
or False
to an attribute,it will be rendered as an HTML5 boolean attribute:
- >>> name = forms.TextInput(attrs={'required': True})
- >>> name.render('name', 'A name')
- '<input name="name" type="text" value="A name" required />'
- >>>
- >>> name = forms.TextInput(attrs={'required': False})
- >>> name.render('name', 'A name')
- '<input name="name" type="text" value="A name" />'
supports_microseconds
An attribute that defaults to
True
. If set toFalse
, themicroseconds part ofdatetime
andtime
values will be set to0
.formatvalue
(_value)[source]Cleans and returns a value for use in the widget template.
value
isn't guaranteed to be valid input, therefore subclass implementationsshould program defensively.getcontext
(_name, value, attrs)[source]- New in Django 1.11.
Returns a dictionary of values to use when rendering the widgettemplate. By default, the dictionary contains a single key,'widget'
, which is a dictionary representation of the widgetcontaining the following keys:
- <code>'name'</code>: The name of the field from the <code>name</code> argument.
- <code>'is_hidden'</code>: A boolean indicating whether or not this widget ishidden.
- <code>'required'</code>: A boolean indicating whether or not the field forthis widget is required.
- <code>'value'</code>: The value as returned by [<code>format_value()</code>]($feafe2d4968db5a9.md#django.forms.Widget.format_value).
- <code>'attrs'</code>: HTML attributes to be set on the rendered widget. Thecombination of the [<code>attrs</code>]($feafe2d4968db5a9.md#django.forms.Widget.attrs) attribute and the <code>attrs</code> argument.
- <code>'template_name'</code>: The value of <code>self.template_name</code>.
Widget
subclasses can provide custom context values by overridingthis method.
idforlabel
(_id)[source]- Returns the HTML ID attribute of this widget for use by a
<label>
,given the ID of the field. ReturnsNone
if an ID isn't available.
This hook is necessary because some widgets have multiple HTMLelements and, thus, multiple IDs. In that case, this method shouldreturn an ID value that corresponds to the first ID in the widget'stags.
render
(name, value, attrs=None, renderer=None)[source]- Renders a widget to HTML using the given renderer. If
renderer
isNone
, the renderer from theFORM_RENDERER
setting isused.
Changed in Django 1.11:The renderer
argument was added. Support for subclasses thatdon't accept it will be removed in Django 2.1.
valuefrom_datadict
(_data, files, name)[source]Given a dictionary of data and this widget's name, returns the valueof this widget.
files
may contain data coming fromrequest.FILES
. ReturnsNone
if a value wasn't provided. Note also thatvalue_from_datadict
maybe called more than once during handling of form data, so if youcustomize it and add expensive processing, you should implement somecaching mechanism yourself.valueomitted_from_data
(_data, files, name)[source]- Given
data
andfiles
dictionaries and this widget's name,returns whether or not there's data or files for the widget.
The method's result affects whether or not a field in a model formfalls back to its default.
Special cases are CheckboxInput
,CheckboxSelectMultiple
, andSelectMultiple
, which always returnFalse
because an unchecked checkbox and unselected<select multiple>
don't appear in the data of an HTML formsubmission, so it's unknown whether or not the user submitted a value.
userequired_attribute
(_initial)[source]- Given a form field's
initial
value, returns whether or not thewidget can be rendered with therequired
HTML attribute. Forms usethis method along withField.required
andForm.use_required_attribute
to determine whether or notto display therequired
attribute for each field.
By default, returns False
for hidden widgets and True
otherwise. Special cases are ClearableFileInput
,which returns False
when initial
is not set, andCheckboxSelectMultiple
, which always returnsFalse
because browser validation would require all checkboxes to bechecked instead of at least one.
Override this method in custom widgets that aren't compatible withbrowser validation. For example, a WSYSIWG text editor widget backed bya hidden textarea
element may want to always return False
toavoid browser validation on the hidden field.
MultiWidget
- class
MultiWidget
(widgets, attrs=None)[source] - A widget that is composed of multiple widgets.
MultiWidget
works hand in hand with theMultiValueField
.
MultiWidget
has one required argument:
And one required method:
decompress
(value)[source]- This method takes a single "compressed" value from the field andreturns a list of "decompressed" values. The input value can beassumed valid, but not necessarily non-empty.
This method must be implemented by the subclass, and since thevalue may be empty, the implementation must be defensive.
The rationale behind "decompression" is that it is necessary to "split"the combined value of the form field into the values for each widget.
An example of this is how SplitDateTimeWidget
turns adatetime
value into a list with date and time splitinto two separate values:
- from django.forms import MultiWidget
- class SplitDateTimeWidget(MultiWidget):
- # ...
- def decompress(self, value):
- if value:
- return [value.date(), value.time().replace(microsecond=0)]
- return [None, None]
Tip
Note that MultiValueField
has acomplementary method compress()
with the opposite responsibility - to combine cleaned values ofall member fields into one.
It provides some custom context:
getcontext
(_name, value, attrs)[source]- In addition to the
'widget'
key described inWidget.get_context()
,MultiValueWidget
adds awidget['subwidgets']
key.
These can be looped over in the widget template:
- {% for subwidget in widget.subwidgets %}
- {% include widget.template_name with widget=subwidget %}
- {% endfor %}
Here's an example widget which subclasses MultiWidget
to displaya date with the day, month, and year in different select boxes. This widgetis intended to be used with a DateField
rather thana MultiValueField
, thus we have implementedvalue_from_datadict()
:
- from datetime import date
- from django.forms import widgets
- class DateSelectorWidget(widgets.MultiWidget):
- def __init__(self, attrs=None):
- # create choices for days, months, years
- # example below, the rest snipped for brevity.
- years = [(year, year) for year in (2011, 2012, 2013)]
- _widgets = (
- widgets.Select(attrs=attrs, choices=days),
- widgets.Select(attrs=attrs, choices=months),
- widgets.Select(attrs=attrs, choices=years),
- )
- super().__init__(_widgets, attrs)
- def decompress(self, value):
- if value:
- return [value.day, value.month, value.year]
- return [None, None, None]
- def value_from_datadict(self, data, files, name):
- datelist = [
- widget.value_from_datadict(data, files, name + '_%s' % i)
- for i, widget in enumerate(self.widgets)]
- try:
- D = date(
- day=int(datelist[0]),
- month=int(datelist[1]),
- year=int(datelist[2]),
- )
- except ValueError:
- return ''
- else:
- return str(D)
The constructor creates several Select
widgets in a tuple. Thesuper
class uses this tuple to setup the widget.
The required method decompress()
breaks up adatetime.date
value into the day, month, and year values correspondingto each widget. Note how the method handles the case where value
isNone
.
The default implementation of value_from_datadict()
returnsa list of values corresponding to each Widget
. This is appropriatewhen using a MultiWidget
with a MultiValueField
,but since we want to use this widget with a DateField
which takes a single value, we have overridden this method to combine thedata of all the subwidgets into a datetime.date
. The method extractsdata from the POST
dictionary and constructs and validates the date.If it is valid, we return the string, otherwise, we return an empty stringwhich will cause form.is_valid
to return False
.
Built-in widgets
Django provides a representation of all the basic HTML widgets, plus somecommonly used groups of widgets in the django.forms.widgets
module,including the input of text, various checkboxesand selectors, uploading files,and handling of multi-valued input.
Widgets handling input of text
These widgets make use of the HTML elements input
and textarea
.
TextInput
- class
TextInput
[source] input_type
:'text'
template_name
:'django/forms/widgets/text.html'
- Renders as:
<input type="text" …>
NumberInput
- class
NumberInput
[source] input_type
:'number'
template_name
:'django/forms/widgets/number.html'
- Renders as:
<input type="number" …>
Beware that not all browsers support entering localized numbers innumber
input types. Django itself avoids using them for fields havingtheirlocalize
property set toTrue
.
EmailInput
- class
EmailInput
[source] input_type
:'email'
template_name
:'django/forms/widgets/email.html'
- Renders as:
<input type="email" …>
URLInput
- class
URLInput
[source] input_type
:'url'
template_name
:'django/forms/widgets/url.html'
- Renders as:
<input type="url" …>
PasswordInput
- class
PasswordInput
[source]
HiddenInput
- class
HiddenInput
[source] input_type
:'hidden'
template_name
:'django/forms/widgets/hidden.html'
- Renders as:
<input type="hidden" …>
Note that there also is aMultipleHiddenInput
widget thatencapsulates a set of hidden input elements.
DateInput
- class
DateInput
[source] input_type
:'text'
template_name
:'django/forms/widgets/date.html'
Renders as:
<input type="text" …>
Takes same arguments asTextInput
, with one more optional argument:- The format in which this field's initial value will be displayed.
If no format
argument is provided, the default format is the firstformat found in DATE_INPUT_FORMATS
and respectsFormat localization.
DateTimeInput
- class
DateTimeInput
[source] input_type
:'text'
template_name
:'django/forms/widgets/datetime.html'
Renders as:
<input type="text" …>
Takes same arguments asTextInput
, with one more optional argument:- The format in which this field's initial value will be displayed.
If no format
argument is provided, the default format is the firstformat found in DATETIME_INPUT_FORMATS
and respectsFormat localization.
By default, the microseconds part of the time value is always set to 0
.If microseconds are required, use a subclass with thesupports_microseconds
attribute set to True
.
TimeInput
- class
TimeInput
[source] input_type
:'text'
template_name
:'django/forms/widgets/time.html'
Renders as:
<input type="text" …>
Takes same arguments asTextInput
, with one more optional argument:- The format in which this field's initial value will be displayed.
If no format
argument is provided, the default format is the firstformat found in TIME_INPUT_FORMATS
and respectsFormat localization.
For the treatment of microseconds, see DateTimeInput
.
Textarea
- class
Textarea
[source] template_name
:'django/forms/widgets/textarea.html'
- Renders as:
<textarea>…</textarea>
Selector and checkbox widgets
These widgets make use of the HTML elements <select>
,<input type="checkbox">
, and <input type="radio">
.
Widgets that render multiple choices have an option_template_name
attributethat specifies the template used to render each choice. For example, for theSelect
widget, select_option.html
renders the <option>
for a<select>
.
CheckboxInput
- class
CheckboxInput
[source]
Select
- class
Select
[source] template_name
:'django/forms/widgets/select.html'
option_template_name
:'django/forms/widgets/select_option.html'
- Renders as:
<select><option …>…</select>
choices
- This attribute is optional when the form field does not have a
choices
attribute. If it does, it will override anything you sethere when the attribute is updated on theField
.
NullBooleanSelect
- class
NullBooleanSelect
[source] template_name
:'django/forms/widgets/select.html'
option_template_name
:'django/forms/widgets/select_option.html'
Select widget with options 'Unknown', 'Yes' and 'No'
SelectMultiple
- class
SelectMultiple
[source] template_name
:'django/forms/widgets/select.html'
option_template_name
:'django/forms/widgets/select_option.html'
Similar toSelect
, but allows multiple selection:<select multiple="multiple">…</select>
RadioSelect
- class
RadioSelect
[source] template_name
:'django/forms/widgets/radio.html'
option_template_name
:'django/forms/widgets/radio_option.html'
Similar toSelect
, but rendered as a list of radio buttons within<li>
tags:
- <ul>
- <li><input type="radio" name="..."></li>
- ...
- </ul>
For more granular control over the generated markup, you can loop over theradio buttons in the template. Assuming a form myform
with a fieldbeatles
that uses a RadioSelect
as its widget:
- {% for radio in myform.beatles %}
- <div class="myradio">
- {{ radio }}
- </div>
- {% endfor %}
This would generate the following HTML:
- <div class="myradio">
- <label for="id_beatles_0"><input id="id_beatles_0" name="beatles" type="radio" value="john" required /> John</label>
- </div>
- <div class="myradio">
- <label for="id_beatles_1"><input id="id_beatles_1" name="beatles" type="radio" value="paul" required /> Paul</label>
- </div>
- <div class="myradio">
- <label for="id_beatles_2"><input id="id_beatles_2" name="beatles" type="radio" value="george" required /> George</label>
- </div>
- <div class="myradio">
- <label for="id_beatles_3"><input id="id_beatles_3" name="beatles" type="radio" value="ringo" required /> Ringo</label>
- </div>
That included the <label>
tags. To get more granular, you can use eachradio button's tag
, choice_label
and id_for_label
attributes.For example, this template…
- {% for radio in myform.beatles %}
- <label for="{{ radio.id_for_label }}">
- {{ radio.choice_label }}
- <span class="radio">{{ radio.tag }}</span>
- </label>
- {% endfor %}
…will result in the following HTML:
- <label for="id_beatles_0">
- John
- <span class="radio"><input id="id_beatles_0" name="beatles" type="radio" value="john" required /></span>
- </label>
- <label for="id_beatles_1">
- Paul
- <span class="radio"><input id="id_beatles_1" name="beatles" type="radio" value="paul" required /></span>
- </label>
- <label for="id_beatles_2">
- George
- <span class="radio"><input id="id_beatles_2" name="beatles" type="radio" value="george" required /></span>
- </label>
- <label for="id_beatles_3">
- Ringo
- <span class="radio"><input id="id_beatles_3" name="beatles" type="radio" value="ringo" required /></span>
- </label>
If you decide not to loop over the radio buttons — e.g., if your templatesimply includes {{ myform.beatles }}
— they'll be output in a <ul>
with <li>
tags, as above.
The outer <ul>
container receives the id
attribute of the widget,if defined, or BoundField.auto_id
otherwise.
When looping over the radio buttons, the label
and input
tags includefor
and id
attributes, respectively. Each radio button has anid_for_label
attribute to output the element's ID.
CheckboxSelectMultiple
- class
CheckboxSelectMultiple
[source] template_name
:'django/forms/widgets/checkbox_select.html'
option_template_name
:'django/forms/widgets/checkbox_option.html'
Similar toSelectMultiple
, but rendered as a list of checkboxes:
- <ul>
- <li><input type="checkbox" name="..." ></li>
- ...
- </ul>
The outer <ul>
container receives the id
attribute of the widget,if defined, or BoundField.auto_id
otherwise.
Like RadioSelect
, you can loop over the individual checkboxes for thewidget's choices. Unlike RadioSelect
, the checkboxes won't include therequired
HTML attribute if the field is required because browser validationwould require all checkboxes to be checked instead of at least one.
When looping over the checkboxes, the label
and input
tags includefor
and id
attributes, respectively. Each checkbox has anid_for_label
attribute to output the element's ID.
File upload widgets
FileInput
- class
FileInput
[source] template_name
:'django/forms/widgets/file.html'
- Renders as:
<input type="file" …>
ClearableFileInput
- class
ClearableFileInput
[source] template_name
:'django/forms/widgets/clearable_file_input.html'
- Renders as:
<input type="file" …>
with an additional checkboxinput to clear the field's value, if the field is not required and hasinitial data.
Composite widgets
MultipleHiddenInput
- class
MultipleHiddenInput
[source] template_name
:'django/forms/widgets/multiple_hidden.html'
Renders as: multiple
<input type="hidden" …>
tagsA widget that handles multiple hidden widgets for fields that have a listof values.- This attribute is optional when the form field does not have a
choices
attribute. If it does, it will override anything you sethere when the attribute is updated on theField
.
SplitDateTimeWidget
- class
SplitDateTimeWidget
[source] template_name
:'django/forms/widgets/splitdatetime.html'
Wrapper (usingMultiWidget
) around two widgets:DateInput
for the date, andTimeInput
for the time. Must be used withSplitDateTimeField
rather thanDateTimeField
.
SplitDateTimeWidget
has several optional arguments:
date_format
Similar to
DateInput.format
Similar to
TimeInput.format
time_attrs
- New in Django 2.0.
Similar to Widget.attrs
. A dictionary containing HTMLattributes to be set on the rendered DateInput
andTimeInput
widgets, respectively. If these attributes aren'tset, Widget.attrs
is used instead.
SplitHiddenDateTimeWidget
- class
SplitHiddenDateTimeWidget
[source] template_name
:'django/forms/widgets/splithiddendatetime.html'
Similar toSplitDateTimeWidget
, but usesHiddenInput
forboth date and time.
SelectDateWidget
- class
SelectDateWidget
[source] template_name
:'django/forms/widgets/select_date.html'
Wrapper around threeSelect
widgets: one each formonth, day, and year.
Takes several optional arguments:
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.
- An optional dict of months to use in the "months" select box.
The keys of the dict correspond to the month number (1-indexed) andthe values are the displayed months:
- MONTHS = {
- 1:_('jan'), 2:_('feb'), 3:_('mar'), 4:_('apr'),
- 5:_('may'), 6:_('jun'), 7:_('jul'), 8:_('aug'),
- 9:_('sep'), 10:_('oct'), 11:_('nov'), 12:_('dec')
- }
empty_label
- If the
DateField
is not required,SelectDateWidget
will have an empty choice at the top of thelist (which is—-
by default). You can change the text of thislabel with theempty_label
attribute.empty_label
can be astring
,list
, ortuple
. When a string is used, all selectboxes will each have an empty choice with this label. Ifempty_label
is alist
ortuple
of 3 string elements, the select boxes willhave their own custom label. The labels should be in this order('year_label', 'month_label', 'day_label')
.
- # A custom empty label with string
- field1 = forms.DateField(widget=SelectDateWidget(empty_label="Nothing"))
- # A custom empty label with tuple
- field1 = forms.DateField(
- widget=SelectDateWidget(
- empty_label=("Choose Year", "Choose Month", "Choose Day"),
- ),
- )