A widget is Django’s representation of an 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.
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'.
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Widgets should not be confused with the form fields. Form fields deal with the logic of input validation and are used directly in templates. Widgets deal with rendering of HTML form input elements on the web page and extraction of raw submitted data. However, widgets do need to be assigned to form fields.
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 Built-in Field classes.
However, if you want to use a different widget for a field, you can
use the 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 Textarea
widget, rather than the default TextInput widget.
Many widgets have optional extra arguments; they can be set when defining the
widget on the field. In the following example, the
years attribute is set for a
SelectDateWidget:
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 widgets are available and which arguments they accept.
Select widget¶Widgets inheriting from the 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 Select widget itself uses a
<select> HTML list representation, while RadioSelect uses radio
buttons.
Select widgets are used by default on ChoiceField fields. The
choices displayed on the widget are inherited from the ChoiceField and
changing ChoiceField.choices will update 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 choices attribute can however be used
with fields which are not based on choice – such as a CharField –
but it is recommended to use a ChoiceField-based field when the
choices are inherent to the model and not just the representational widget.
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. This
means, for example, that all TextInput widgets will appear the same
on your web pages.
There are two ways to customize widgets: per widget instance and per widget class.
If you want to make one widget instance look different from another, you will need to specify additional attributes at the time when the widget object is instantiated and assigned to a form field (and perhaps add some rules to your CSS files).
For example, take the following 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 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)
>>> print(f)
<div>Name:<input type="text" name="name" required></div>
<div>Url:<input type="url" name="url" required></div>
<div>Comment:<input type="text" name="comment" required></div>
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. It is also possible to specify
the «type» attribute to take advantage of the new HTML5 input types. To do
this, 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)
>>> print(f)
<div>Name:<input type="text" name="name" class="special" required></div>
<div>Url:<input type="url" name="url" required></div>
<div>Comment:<input type="text" name="comment" size="40" required></div>
You can also set the HTML id using attrs. See
BoundField.id_for_label for an example.
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 either define a „Media” inner class or create a „media” property.
These methods involve somewhat advanced Python programming and are described in detail in the Form Assets topic guide.
Base widget classes Widget and MultiWidget are subclassed by
all the built-in widgets and may serve as a
foundation for custom widgets.
Widget¶Widget(attrs=None)¶This abstract class cannot be rendered, but provides the basic attribute
attrs. You may also implement or override the
render() method on custom widgets.
attrs¶A dictionary containing HTML attributes to be set on the rendered widget.
>>> 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 to False, the
microseconds part of datetime and
time values will be set to 0.
format_value(value)¶Cleans and returns a value for use in the widget template. value
isn’t guaranteed to be valid input, therefore subclass implementations
should program defensively.
get_context(name, value, attrs)¶Returns a dictionary of values to use when rendering the widget
template. By default, the dictionary contains a single key,
'widget', which is a dictionary representation of the widget
containing the following keys:
'name': The name of the field from the name argument.'is_hidden': A boolean indicating whether or not this widget is
hidden.'required': A boolean indicating whether or not the field for
this widget is required.'value': The value as returned by format_value().'attrs': HTML attributes to be set on the rendered widget. The
combination of the attrs attribute and the attrs argument.'template_name': The value of self.template_name.Widget subclasses can provide custom context values by overriding
this method.
id_for_label(id_)¶Returns the HTML ID attribute of this widget for use by a <label>,
given the ID of the field. Returns an empty string if an ID isn’t
available.
This hook is necessary because some widgets have multiple HTML elements and, thus, multiple IDs. In that case, this method should return an ID value that corresponds to the first ID in the widget’s tags.
render(name, value, attrs=None, renderer=None)¶Renders a widget to HTML using the given renderer. If renderer is
None, the renderer from the FORM_RENDERER setting is
used.
value_from_datadict(data, files, name)¶Given a dictionary of data and this widget’s name, returns the value
of this widget. files may contain data coming from
request.FILES. Returns None
if a value wasn’t provided. Note also that value_from_datadict may
be called more than once during handling of form data, so if you
customize it and add expensive processing, you should implement some
caching mechanism yourself.
value_omitted_from_data(data, files, name)¶Given data and files 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 form falls back to its default.
Special cases are CheckboxInput,
CheckboxSelectMultiple, and
SelectMultiple, which always return
False because an unchecked checkbox and unselected
<select multiple> don’t appear in the data of an HTML form
submission, so it’s unknown whether or not the user submitted a value.
use_fieldset¶An attribute to identify if the widget should be grouped in a
<fieldset> with a <legend> when rendered. Defaults to False
but is True when the widget contains multiple <input> tags such as
CheckboxSelectMultiple,
RadioSelect,
MultiWidget,
SplitDateTimeWidget, and
SelectDateWidget.
use_required_attribute(initial)¶Given a form field’s initial value, returns whether or not the
widget can be rendered with the required HTML attribute. Forms use
this method along with Field.required and Form.use_required_attribute to determine whether or not
to display the required attribute for each field.
By default, returns False for hidden widgets and True
otherwise. Special cases are FileInput and
ClearableFileInput, which return False when
initial is set, and CheckboxSelectMultiple,
which always returns False because browser validation would require
all checkboxes to be checked instead of at least one.
Override this method in custom widgets that aren’t compatible with
browser validation. For example, a WSYSIWG text editor widget backed by
a hidden textarea element may want to always return False to
avoid browser validation on the hidden field.
MultiWidget¶MultiWidget(widgets, attrs=None)¶A widget that is composed of multiple widgets.
MultiWidget works hand in hand with the
MultiValueField.
MultiWidget has one required argument:
widgets¶An iterable containing the widgets needed. For example:
>>> from django.forms import MultiWidget, TextInput
>>> widget = MultiWidget(widgets=[TextInput, TextInput])
>>> widget.render("name", ["john", "paul"])
'<input type="text" name="name_0" value="john"><input type="text" name="name_1" value="paul">'
You may provide a dictionary in order to specify custom suffixes for
the name attribute on each subwidget. In this case, for each
(key, widget) pair, the key will be appended to the name of the
widget in order to generate the attribute value. You may provide the
empty string ('') for a single key, in order to suppress the suffix
for one widget. For example:
>>> widget = MultiWidget(widgets={"": TextInput, "last": TextInput})
>>> widget.render("name", ["john", "paul"])
'<input type="text" name="name" value="john"><input type="text" name="name_last" value="paul">'
And one required method:
decompress(value)¶This method takes a single „compressed” value from the field and returns a list of „decompressed” values. The input value can be assumed valid, but not necessarily non-empty.
This method must be implemented by the subclass, and since the value 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 a
datetime value into a list with date and time split
into two separate values:
from django.forms import MultiWidget
class SplitDateTimeWidget(MultiWidget):
# ...
def decompress(self, value):
if value:
return [value.date(), value.time()]
return [None, None]
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Note that MultiValueField has a
complementary method compress()
with the opposite responsibility - to combine cleaned values of
all member fields into one.
It provides some custom context:
get_context(name, value, attrs)¶In addition to the 'widget' key described in
Widget.get_context(), MultiWidget adds a
widget['subwidgets'] key.
These can be looped over in the widget template:
{% for subwidget in widget.subwidgets %}
{% include subwidget.template_name with widget=subwidget %}
{% endfor %}
Here’s an example widget which subclasses MultiWidget to display
a date with the day, month, and year in different select boxes. This widget
is intended to be used with a DateField rather than
a MultiValueField, thus we have implemented
value_from_datadict():
from datetime import date
from django import forms
class DateSelectorWidget(forms.MultiWidget):
def __init__(self, attrs=None):
days = {day: day for day in range(1, 32)}
months = {month: month for month in range(1, 13)}
years = {year: year for year in [2018, 2019, 2020]}
widgets = [
forms.Select(attrs=attrs, choices=days),
forms.Select(attrs=attrs, choices=months),
forms.Select(attrs=attrs, choices=years),
]
super().__init__(widgets, attrs)
def decompress(self, value):
if isinstance(value, date):
return [value.day, value.month, value.year]
elif isinstance(value, str):
year, month, day = value.split("-")
return [day, month, year]
return [None, None, None]
def value_from_datadict(self, data, files, name):
day, month, year = super().value_from_datadict(data, files, name)
# DateField expects a single string that it can parse into a date.
return "{}-{}-{}".format(year, month, day)
The constructor creates several Select widgets in a list. The
super() method uses this list to set up the widget.
The required method decompress() breaks up a
datetime.date value into the day, month, and year values corresponding
to each widget. If an invalid date was selected, such as the non-existent
30th February, the DateField passes this method a
string instead, so that needs parsing. The final return handles when
value is None, meaning we don’t have any defaults for our
subwidgets.
The default implementation of value_from_datadict() returns a
list of values corresponding to each Widget. This is appropriate when
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. The
implementation here combines the data from the subwidgets into a string in
the format that DateField expects.
Django provides a representation of all the basic HTML widgets, plus some
commonly used groups of widgets in the django.forms.widgets module,
including the input of text, various checkboxes
and selectors, uploading files,
and handling of multi-valued input.
These widgets make use of the HTML elements input and textarea.
TextInput¶TextInput¶input_type: 'text'template_name: 'django/forms/widgets/text.html'<input type="text" ...>NumberInput¶NumberInput¶input_type: 'number'template_name: 'django/forms/widgets/number.html'<input type="number" ...>Beware that not all browsers support entering localized numbers in
number input types. Django itself avoids using them for fields having
their localize property set to True.
EmailInput¶EmailInput¶input_type: 'email'template_name: 'django/forms/widgets/email.html'<input type="email" ...>URLInput¶URLInput¶input_type: 'url'template_name: 'django/forms/widgets/url.html'<input type="url" ...>PasswordInput¶PasswordInput¶input_type: 'password'template_name: 'django/forms/widgets/password.html'<input type="password" ...>Takes one optional argument:
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).
DateInput¶DateInput¶input_type: 'text'template_name: 'django/forms/widgets/date.html'<input type="text" ...>Takes same arguments as TextInput, with one more optional argument:
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 DATE_INPUT_FORMATS and respects
Format localization. %U, %W, and %j formats are not
supported by this widget.
DateTimeInput¶DateTimeInput¶input_type: 'text'template_name: 'django/forms/widgets/datetime.html'<input type="text" ...>Takes same arguments as TextInput, with one more optional argument:
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 DATETIME_INPUT_FORMATS and respects
Format localization. %U, %W, and %j formats are not
supported by this widget.
By default, the microseconds part of the time value is always set to 0.
If microseconds are required, use a subclass with the
supports_microseconds attribute set to True.
TimeInput¶TimeInput¶input_type: 'text'template_name: 'django/forms/widgets/time.html'<input type="text" ...>Takes same arguments as TextInput, with one more optional argument:
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 TIME_INPUT_FORMATS and respects
Format localization.
For the treatment of microseconds, see DateTimeInput.
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 attribute
that specifies the template used to render each choice. For example, for the
Select widget, select_option.html renders the <option> for a
<select>.
CheckboxInput¶Select¶Select¶template_name: 'django/forms/widgets/select.html'option_template_name: 'django/forms/widgets/select_option.html'<select><option ...>...</select>NullBooleanSelect¶NullBooleanSelect¶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¶RadioSelect¶RadioSelect¶template_name: 'django/forms/widgets/radio.html'option_template_name: 'django/forms/widgets/radio_option.html'Similar to Select, but rendered as a list of radio buttons within
<div> tags:
<div>
<div><input type="radio" name="..."></div>
...
</div>
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:
<fieldset>
<legend>{{ myform.beatles.label }}</legend>
{% for radio in myform.beatles %}
<div class="myradio">
{{ radio }}
</div>
{% endfor %}
</fieldset>
This would generate the following HTML:
<fieldset>
<legend>Radio buttons</legend>
<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>
</fieldset>
That included the <label> tags. To get more granular, you can use each
radio button’s tag, choice_label and id_for_label attributes.
For example, this template…
<fieldset>
<legend>{{ myform.beatles.label }}</legend>
{% for radio in myform.beatles %}
<label for="{{ radio.id_for_label }}">
{{ radio.choice_label }}
<span class="radio">{{ radio.tag }}</span>
</label>
{% endfor %}
</fieldset>
…will result in the following HTML:
<fieldset>
<legend>Radio buttons</legend>
<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>
</fieldset>
If you decide not to loop over the radio buttons – e.g., if your template
includes {{ myform.beatles }} – they’ll be output in a <div> with
<div> tags, as above.
The outer <div> 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 include
for and id attributes, respectively. Each radio button has an
id_for_label attribute to output the element’s ID.
CheckboxSelectMultiple¶CheckboxSelectMultiple¶template_name: 'django/forms/widgets/checkbox_select.html'option_template_name: 'django/forms/widgets/checkbox_option.html'Similar to SelectMultiple, but rendered as a list of checkboxes:
<div>
<div><input type="checkbox" name="..." ></div>
...
</div>
The outer <div> 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 the
widget’s choices. Unlike RadioSelect, the checkboxes won’t include the
required HTML attribute if the field is required because browser validation
would require all checkboxes to be checked instead of at least one.
When looping over the checkboxes, the label and input tags include
for and id attributes, respectively. Each checkbox has an
id_for_label attribute to output the element’s ID.
SplitDateTimeWidget¶SplitDateTimeWidget¶template_name: 'django/forms/widgets/splitdatetime.html'Wrapper (using MultiWidget) around two widgets: DateInput
for the date, and TimeInput for the time. Must be used with
SplitDateTimeField rather than DateTimeField.
SplitDateTimeWidget has several optional arguments:
date_format¶Similar to DateInput.format
time_format¶Similar to TimeInput.format
date_attrs¶time_attrs¶Similar to Widget.attrs. A dictionary containing HTML
attributes to be set on the rendered DateInput and
TimeInput widgets, respectively. If these attributes aren’t
set, Widget.attrs is used instead.
SelectDateWidget¶SelectDateWidget¶template_name: 'django/forms/widgets/select_date.html'Wrapper around three Select widgets: one each for
month, 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.
months¶An optional dict of months to use in the „months” select box.
The keys of the dict correspond to the month number (1-indexed) and the 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 the
list (which is --- by default). You can change the text of this
label with the empty_label attribute. empty_label can be a
string, list, or tuple. When a string is used, all select
boxes will each have an empty choice with this label. If empty_label
is a list or tuple of 3 string elements, the select boxes will
have 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"),
),
)
sie 06, 2024