Widgets

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.

Tip

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.

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 Built-in Field classes.

However, if you want to use a different widget for a field, you can just 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.

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 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.

Widgets inheriting from the 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.

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. 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.

Styling widget instances

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 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 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="url" 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. 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'}))

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="url" name="url"/></td></tr>
<tr><th>Comment:</th><td><input type="text" name="comment" size="40"/></td></tr>

You can also set the HTML id using attrs. See BoundField.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 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

Base widget classes Widget and MultiWidget are subclassed by all the built-in widgets and may serve as a foundation 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 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.

In older versions, this attribute was only defined on the date and time widgets (as False).

id_for_label(self, id_) [source]

Returns the HTML ID attribute of this widget for use by a <label>, given the ID of the field. Returns None 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) [source]

Returns HTML for the widget, as a Unicode string. This method must be implemented by the subclass, otherwise NotImplementedError will be raised.

The ‘value’ given is not guaranteed to be valid input, therefore subclass implementations should program defensively.

value_from_datadict(data, files, name) [source]

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.

MultiWidget

class MultiWidget(widgets, attrs=None) [source]

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.

And one required method:

decompress(value) [source]

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().replace(microsecond=0)]
        return [None, None]

Tip

Note that MultiValueField has a complementary method compress() with the opposite responsibility - to combine cleaned values of all member fields into one.

Other methods that may be useful to override include:

render(name, value, attrs=None) [source]

Argument value is handled differently in this method from the subclasses of Widget because it has to figure out how to split a single value for display in multiple widgets.

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.

If value is a list, the output of render() will be a concatenation of rendered child widgets. If value is not a list, it will first be processed by the method decompress() to create the list and then rendered.

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.

Unlike in the single value widgets, method render() need not be implemented in the subclasses.

format_output(rendered_widgets) [source]

Given a list of rendered widgets (as strings), returns a Unicode string representing the HTML for the whole lot.

This hook allows you to format the HTML design of the widgets any way you’d like.

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.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(DateSelectorWidget, self).__init__(_widgets, attrs)

    def decompress(self, value):
        if value:
            return [value.day, value.month, value.year]
        return [None, None, None]

    def format_output(self, rendered_widgets):
        return ''.join(rendered_widgets)

    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. The super class uses this tuple to setup the widget.

The format_output() method is fairly vanilla here (in fact, it’s the same as what’s been implemented as the default for MultiWidget), but the idea is that you could add custom HTML between the widgets should you wish.

The required method decompress() breaks up a datetime.date value into the day, month, and year values corresponding to each widget. Note how the method handles the case where value is None.

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 to combine the data of all the subwidgets into a datetime.date. The method extracts data from the POST dictionary and constructs and validates the date. If it is valid, we return the string, otherwise, we return an empty string which will cause form.is_valid to return False.

Built-in widgets

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.

Widgets handling input of text

These widgets make use of the HTML elements input and textarea.

TextInput

class TextInput [source]

Text input: <input type="text" ...>

NumberInput

class NumberInput [source]

Text input: <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

class EmailInput [source]

Text input: <input type="email" ...>

URLInput

class URLInput [source]

Text input: <input type="url" ...>

PasswordInput

class PasswordInput [source]

Password input: <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).

HiddenInput

class HiddenInput [source]

Hidden input: <input type='hidden' ...>

Note that there also is a MultipleHiddenInput widget that encapsulates a set of hidden input elements.

DateInput

class DateInput [source]

Date input as a simple text box: <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.

DateTimeInput

class DateTimeInput [source]

Date/time input as a simple text box: <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.

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

class TimeInput [source]

Time input as a simple text box: <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.

Textarea

class Textarea [source]

Text area: <textarea>...</textarea>

Selector and checkbox widgets

CheckboxInput

class CheckboxInput [source]

Checkbox: <input type='checkbox' ...>

Takes one optional argument:

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 [source]

Select widget: <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 set here when the attribute is updated on the Field.

NullBooleanSelect

class NullBooleanSelect [source]

Select widget with options ‘Unknown’, ‘Yes’ and ‘No’

SelectMultiple

class SelectMultiple [source]

Similar to Select, but allows multiple selection: <select multiple='multiple'>...</select>

RadioSelect

class RadioSelect [source]

Similar to Select, 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 the radio buttons in the template. Assuming a form myform with a field beatles 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" /> John</label>
</div>
<div class="myradio">
    <label for="id_beatles_1"><input id="id_beatles_1" name="beatles" type="radio" value="paul" /> Paul</label>
</div>
<div class="myradio">
    <label for="id_beatles_2"><input id="id_beatles_2" name="beatles" type="radio" value="george" /> George</label>
</div>
<div class="myradio">
    <label for="id_beatles_3"><input id="id_beatles_3" name="beatles" type="radio" value="ringo" /> Ringo</label>
</div>

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...

{% 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" /></span>
</label>

<label for="id_beatles_1">
    Paul
    <span class="radio"><input id="id_beatles_1" name="beatles" type="radio" value="paul" /></span>
</label>

<label for="id_beatles_2">
    George
    <span class="radio"><input id="id_beatles_2" name="beatles" type="radio" value="george" /></span>
</label>

<label for="id_beatles_3">
    Ringo
    <span class="radio"><input id="id_beatles_3" name="beatles" type="radio" 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.

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 include for and id attributes, respectively. Each radio button has an id_for_label attribute to output the element’s ID.

CheckboxSelectMultiple

class CheckboxSelectMultiple [source]

Similar to SelectMultiple, but rendered as a list of check buttons:

<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 now loop over the individual checkboxes making up the lists. See the documentation of RadioSelect for more details.

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.

File upload widgets

FileInput

class FileInput [source]

File upload input: <input type='file' ...>

ClearableFileInput

class ClearableFileInput [source]

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.

Composite widgets

MultipleHiddenInput

class MultipleHiddenInput [source]

Multiple <input type='hidden' ...> widgets.

A widget that handles multiple hidden widgets for fields that have a list of values.

choices

This attribute is optional when the form field does not have a choices attribute. If it does, it will override anything you set here when the attribute is updated on the Field.

SplitDateTimeWidget

class SplitDateTimeWidget [source]

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 two optional attributes:

date_format

Similar to DateInput.format

time_format

Similar to TimeInput.format

SplitHiddenDateTimeWidget

class SplitHiddenDateTimeWidget [source]

Similar to SplitDateTimeWidget, but uses HiddenInput for both date and time.

SelectDateWidget

class SelectDateWidget [source]

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"),
    ),
)

This widget used to be located in the django.forms.extras.widgets package. It is now defined in django.forms.widgets and like the other widgets it can be imported directly from django.forms.

© Django Software Foundation and individual contributors
Licensed under the BSD License.
https://docs.djangoproject.com/en/1.9/ref/forms/widgets/