Input Examples and Reference

Supported Input Types

import dash_core_components as dcc
import dash_html_components as html
import dash
from dash.dependencies import Input, Output

app = dash.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")]
)


@app.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_server(debug=True)

Debounce delays the Input processing

# -*- coding: utf-8 -*-
import dash
import dash_core_components as dcc
import dash_html_components as html
from dash.dependencies import Input, Output

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

app = dash.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=""),
        dcc.Input(id="input2", type="text", placeholder="", debounce=True),
        html.Div(id="output"),
    ]
)


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


if __name__ == "__main__":
    app.run_server(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

Fixed and enhanced in Dash v1.1.0

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) typing 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.
Please add extra guard casting like float() within callbacks if needed.

import dash_core_components as dcc
import dash_html_components as html
import dash
from dash.dependencies import Input, Output

app = dash.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", type="number", placeholder="input with range",
            min=10, max=100, step=3,
        ),
        html.Hr(),
        html.Div(id="number-out"),
    ]
)


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


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


Input Properties

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

help(dash_core_components.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
.

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.

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

autoFocus (a value equal to: ‘autoFocus’, ‘autofocus’, ‘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.

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

debounce (boolean; 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 sent
the value back on every change.

disabled (a value equal to: ‘disabled’, ‘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.

inputMode (a value equal to: “verbatim”, “latin”, “latin-name”, “latin-prose”, “full-width-latin”, “kana”, “katakana”, “numeric”, “tel”, “email”, “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.

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.

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.

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.

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.

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.

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.

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.

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

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

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.

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

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.

persisted_props (list of a value equal to: ‘value’s; 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 (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.

persistence_type (a value equal to: ‘local’, ‘session’, ‘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.

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.

readOnly (boolean | a value equal to: ‘readOnly’, ‘readonly’, ‘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’, ‘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.

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.

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).

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).

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.

spellCheck (a value equal to: ‘true’, ‘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.

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.

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

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

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