dcc.Input

The dcc.Input component creates input fields for text, numbers, passwords, and more, allowing dynamic user input.

Examples

Find a few usage examples below.

For more examples of minimal Dash apps that use dcc.Input, go to the community-driven Example Index.

Supported Input Types

from dash import Dash, dcc, html, Input, Output, callback

app = Dash(__name__)

ALLOWED_TYPES = (
    "text", "number", "password", "email", "search",
    "tel", "url", "range", "hidden",
)


app.layout = html.Div(
    [
        dcc.Input(
            id="input_{}".format(_),
            type=_,
            placeholder="input type {}".format(_),
        )
        for _ in ALLOWED_TYPES
    ]
    + [html.Div(id="out-all-types")]
)


@callback(
    Output("out-all-types", "children"),
    [Input("input_{}".format(_), "value") for _ in ALLOWED_TYPES],
)
def cb_render(*vals):
    return " | ".join((str(val) for val in vals if val))


if __name__ == "__main__":
    app.run(debug=True)

Debounce Delays the Input Processing

from dash import Dash, dcc, html, Input, Output, callback

external_stylesheets = ["https://codepen.io/chriddyp/pen/bWLwgP.css"]

app = Dash(__name__, external_stylesheets=external_stylesheets)

app.layout = html.Div(
    [
        html.I("Try typing in input 1 & 2, and observe how debounce is impacting the callbacks. Press Enter and/or Tab key in Input 2 to cancel the delay"),
        html.Br(),
        dcc.Input(id="input1", type="text", placeholder="", style={'marginRight':'10px'}),
        dcc.Input(id="input2", type="text", placeholder="", debounce=True),
        html.Div(id="output"),
    ]
)


@callback(
    Output("output", "children"),
    Input("input1", "value"),
    Input("input2", "value"),
)
def update_output(input1, input2):
    return f'Input 1 {input1} and Input 2 {input2}'


if __name__ == "__main__":
    app.run(debug=True)

Try typing in input 1 & 2, and observe how debounce is impacting the callbacks. Press Enter and/or Tab key in Input 2 to cancel the delay

Number Input

Number type is now close to native HTML5 input behavior across
browsers. We also apply a strict number casting in callbacks:
valid number converts into corresponding number types, and invalid number
converts into None. E.g.

dcc.Input(id='range', type='number', min=2, max=10, step=1)

type 3 and 11 will return respectively integer three and None in Python callbacks.

Important Notice re Integer vs Float:
There is a limitation when converting numbers like 1.0 or 0.0: the
corresponding number type in callbacks is Integer instead of Float.
Add extra guard casting like float() within callbacks if needed.

from dash import Dash, dcc, html, Input, Output, callback

app = Dash(__name__)
app.layout = html.Div(
    [
        dcc.Input(id="dfalse", type="number", placeholder="Debounce False"),
        dcc.Input(
            id="dtrue", type="number",
            debounce=True, placeholder="Debounce True",
        ),
        dcc.Input(
            id="input_range_2", type="number", placeholder="input with range",
            min=10, max=100, step=3,
        ),
        html.Hr(),
        html.Div(id="number-out"),
    ]
)


@callback(
    Output("number-out", "children"),
    Input("dfalse", "value"),
    Input("dtrue", "value"),
    Input("input_range_2", "value"),
)
def number_render(fval, tval, rangeval):
    return "dfalse: {}, dtrue: {}, range: {}".format(fval, tval, rangeval)


if __name__ == "__main__":
    app.run(debug=True)

Input Properties

Access this documentation in your Python terminal with:
```python

help(dash.dcc.Input)
```

Our recommended IDE for writing Dash apps is Dash Enterprise’s
Data Science Workspaces,
which has typeahead support for Dash Component Properties.
Find out if your company is using
Dash Enterprise.

value (string | number; optional):
The value of the input.

type (a value equal to: ‘text’, ‘number’, ‘password’, ‘email’, ‘range’, ‘search’, ‘tel’, ‘url’ or ‘hidden’; default 'text'):
The type of control to render.

debounce (boolean | number; default False):
If True, changes to input will be sent back to the Dash server only on
enter or when losing focus. If it’s False, it will send the value back
on every change. If a number, it will not send anything back to the
Dash server until the user has stopped typing for that number of
seconds.

placeholder (string | number; optional):
A hint to the user of what can be entered in the control . The
placeholder text must not contain carriage returns or line-feeds.
Note: Do not use the placeholder attribute instead of a <label>
element, their purposes are different. The <label> attribute describes
the role of the form element (i.e. it indicates what kind of
information is expected), and the placeholder attribute is a hint
about the format that the content should take. There are cases in
which the placeholder attribute is never displayed to the user, so the
form must be understandable without it.

n_submit (number; default 0):
Number of times the Enter key was pressed while the input had focus.

n_submit_timestamp (number; default -1):
Last time that Enter was pressed.

inputMode (a value equal to: ‘verbatim’, ‘latin’, ‘latin-name’, ‘latin-prose’, ‘full-width-latin’, ‘kana’, ‘katakana’, ‘numeric’, ‘tel’, ‘email’ or ‘url’; optional):
Provides a hint to the browser as to the type of data that might be
entered by the user while editing the element or its contents.

autoComplete (string; optional):
This attribute indicates whether the value of the control can be
automatically completed by the browser.

readOnly (boolean | a value equal to: ‘readOnly’, ‘readonly’ or ‘READONLY’; optional):
This attribute indicates that the user cannot modify the value of the
control. The value of the attribute is irrelevant. If you need
read-write access to the input value, do not add the “readonly”
attribute. It is ignored if the value of the type attribute is hidden,
range, color, checkbox, radio, file, or a button type (such as button
or submit). readOnly is an HTML boolean attribute - it is enabled by a
boolean or ‘readOnly’. Alternative capitalizations readonly &
READONLY are also acccepted.

required (a value equal to: ‘required’ or ‘REQUIRED’ | boolean; optional):
This attribute specifies that the user must fill in a value before
submitting a form. It cannot be used when the type attribute is
hidden, image, or a button type (submit, reset, or button). The
:optional and :required CSS pseudo-classes will be applied to the
field as appropriate. required is an HTML boolean attribute - it is
enabled by a boolean or ‘required’. Alternative capitalizations
REQUIRED are also acccepted.

autoFocus (a value equal to: ‘autoFocus’, ‘autofocus’ or ‘AUTOFOCUS’ | boolean; optional):
The element should be automatically focused after the page loaded.
autoFocus is an HTML boolean attribute - it is enabled by a boolean or
‘autoFocus’. Alternative capitalizations autofocus & AUTOFOCUS are
also acccepted.

disabled (a value equal to: ‘disabled’ or ‘DISABLED’ | boolean; optional):
If True, the input is disabled and can’t be clicked on. disabled is an
HTML boolean attribute - it is enabled by a boolean or ‘disabled’.
Alternative capitalizations DISABLED.

list (string; optional):
Identifies a list of pre-defined options to suggest to the user. The
value must be the id of a <datalist> element in the same document. The
browser displays only options that are valid values for this input
element. This attribute is ignored when the type attribute’s value is
hidden, checkbox, radio, file, or a button type.

multiple (boolean; optional):
This Boolean attribute indicates whether the user can enter more than
one value. This attribute applies when the type attribute is set to
email or file, otherwise it is ignored.

spellCheck (a value equal to: ‘true’ or ‘false’ | boolean; optional):
Setting the value of this attribute to True indicates that the element
needs to have its spelling and grammar checked. The value default
indicates that the element is to act according to a default behavior,
possibly based on the parent element’s own spellcheck value. The value
False indicates that the element should not be checked.

name (string; optional):
The name of the control, which is submitted with the form data.

min (string | number; optional):
The minimum (numeric or date-time) value for this item, which must not
be greater than its maximum (max attribute) value.

max (string | number; optional):
The maximum (numeric or date-time) value for this item, which must not
be less than its minimum (min attribute) value.

step (string | number; default 'any'):
Works with the min and max attributes to limit the increments at which
a numeric or date-time value can be set. It can be the string any or a
positive floating point number. If this attribute is not set to any,
the control accepts only values at multiples of the step value greater
than the minimum.

minLength (string | number; optional):
If the value of the type attribute is text, email, search, password,
tel, or url, this attribute specifies the minimum number of characters
(in Unicode code points) that the user can enter. For other control
types, it is ignored.

maxLength (string | number; optional):
If the value of the type attribute is text, email, search, password,
tel, or url, this attribute specifies the maximum number of characters
(in UTF-16 code units) that the user can enter. For other control
types, it is ignored. It can exceed the value of the size attribute.
If it is not specified, the user can enter an unlimited number of
characters. Specifying a negative number results in the default
behavior (i.e. the user can enter an unlimited number of characters).
The constraint is evaluated only when the value of the attribute has
been changed.

pattern (string; optional):
A regular expression that the control’s value is checked against. The
pattern must match the entire value, not just some subset. Use the
title attribute to describe the pattern to help the user. This
attribute applies when the value of the type attribute is text,
search, tel, url, email, or password, otherwise it is ignored. The
regular expression language is the same as JavaScript RegExp
algorithm, with the ‘u’ parameter that makes it treat the pattern as a
sequence of unicode code points. The pattern is not surrounded by
forward slashes.

selectionStart (string; optional):
The offset into the element’s text content of the first selected
character. If there’s no selection, this value indicates the offset to
the character following the current text input cursor position (that
is, the position the next character typed would occupy).

selectionEnd (string; optional):
The offset into the element’s text content of the last selected
character. If there’s no selection, this value indicates the offset to
the character following the current text input cursor position (that
is, the position the next character typed would occupy).

selectionDirection (string; optional):
The direction in which selection occurred. This is “forward” if the
selection was made from left-to-right in an LTR locale or
right-to-left in an RTL locale, or “backward” if the selection was
made in the opposite direction. On platforms on which it’s possible
this value isn’t known, the value can be “none”; for example, on
macOS, the default direction is “none”, then as the user begins to
modify the selection using the keyboard, this will change to reflect
the direction in which the selection is expanding.

n_blur (number; default 0):
Number of times the input lost focus.

n_blur_timestamp (number; default -1):
Last time the input lost focus.

size (string; optional):
The initial size of the control. This value is in pixels unless the
value of the type attribute is text or password, in which case it is
an integer number of characters. Starting in, this attribute applies
only when the type attribute is set to text, search, tel, url, email,
or password, otherwise it is ignored. In addition, the size must be
greater than zero. If you do not specify a size, a default value of 20
is used.’ simply states “the user agent should ensure that at least
that many characters are visible”, but different characters can have
different widths in certain fonts. In some browsers, a certain string
with x characters will not be entirely visible even if size is defined
to at least x.

style (dict; optional):
The input’s inline styles.

className (string; optional):
The class of the input element.

id (string; optional):
The ID of this component, used to identify dash components in
callbacks. The ID needs to be unique across all of the components in
an app.

loading_state (dict; optional):
Object that holds the loading state object coming from dash-renderer.

loading_state is a dict with keys:

component_name (string; optional):
Holds the name of the component that is loading.
is_loading (boolean; optional):
Determines if the component is loading or not.
prop_name (string; optional):
Holds which property is loading.

persistence (boolean | string | number; optional):
Used to allow user interactions in this component to be persisted when
the component - or the page - is refreshed. If persisted is truthy
and hasn’t changed from its previous value, a value that the user
has changed while using the app will keep that change, as long as the
new value also matches what was given originally. Used in
conjunction with persistence_type.

persisted_props (list of values equal to: ‘value’; default ['value']):
Properties whose user interactions will persist after refreshing the
component or the page. Since only value is allowed this prop can
normally be ignored.

persistence_type (a value equal to: ‘local’, ‘session’ or ‘memory’; default 'local'):
Where persisted user changes will be stored: memory: only kept in
memory, reset on page refresh. local: window.localStorage, data is
kept after the browser quit. session: window.sessionStorage, data is
cleared once the browser quit.