Reference & Documentation

A Source component.
Source is a wrapper for the <source> HTML5 element.
For detailed attribute info see:

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children (list of or a singular dash component, string or number; optional):
The children of this component.

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.

n_clicks (number; default 0):
An integer that represents the number of times that this element has
been clicked on.

n_clicks_timestamp (number; default -1):
An integer that represents the time (in ms since 1970) at which
n_clicks changed. This can be used to tell which button was changed
most recently.

key (string; optional):
A unique identifier for the component, used to improve performance by
React.js while rendering components See for more info.

media (string; optional):
Specifies a hint of the media for which the linked resource was

sizes (string; optional)

src (string; optional):
The URL of the embeddable content.

srcSet (string; optional):
One or more responsive image candidates.

type (string; optional):
Defines the type of the element.

accessKey (string; optional):
Keyboard shortcut to activate or add focus to the element.

className (string; optional):
Often used with CSS to style elements with common properties.

contentEditable (string; optional):
Indicates whether the element’s content is editable.

contextMenu (string; optional):
Defines the ID of a <menu> element which will serve as the element’s
context menu.

dir (string; optional):
Defines the text direction. Allowed values are ltr (Left-To-Right) or
rtl (Right-To-Left).

draggable (string; optional):
Defines whether the element can be dragged.

hidden (a value equal to: ‘hidden’ or ‘HIDDEN’ | boolean; optional):
Prevents rendering of given element, while keeping child elements,
e.g. script elements, active.

lang (string; optional):
Defines the language used in the element.

role (string; optional):
Defines an explicit role for an element for use by assistive

spellCheck (string; optional):
Indicates whether spell checking is allowed for the element.

style (dict; optional):
Defines CSS styles which will override styles previously set.

tabIndex (string; optional):
Overrides the browser’s default tab order and follows the one
specified instead.

title (string; optional):
Text to be displayed in a tooltip when hovering over the element.

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.