@material/snackbar

Snackbars

The MDC Snackbar component is a spec-aligned snackbar/toast component adhering to the Material Design snackbars & toasts requirements. It requires JavaScript to show and hide itself.

Design & API Documentation

• Material Design guidelines: Snackbars & toasts
• Demo

Installation

npm install @material/snackbar

Usage

Snackbar DOM

<div class="mdc-snackbar"
     aria-live="assertive"
     aria-atomic="true"
     aria-hidden="true">
  <div class="mdc-snackbar__text"></div>
  <div class="mdc-snackbar__action-wrapper">
    <button type="button" class="mdc-snackbar__action-button"></button>
  </div>
</div>

Start Aligned Snackbars (tablet and desktop only)

MDC Snackbar can be start aligned (including in RTL contexts). To create a start-aligned snackbar, add the mdc-snackbar--align-start modifier class to the root element.

<div class="mdc-snackbar mdc-snackbar--align-start"
     aria-live="assertive"
     aria-atomic="true"
     aria-hidden="true">
  <div class="mdc-snackbar__text"></div>
  <div class="mdc-snackbar__action-wrapper">
    <button type="button" class="mdc-snackbar__action-button"></button>
  </div>
</div>

Using the JS Component

MDC Snackbar ships with a Component / Foundation combo which provides the API for showing snackbar messages with optional action.

Including in code

ES2015

import {MDCSnackbar, MDCSnackbarFoundation} from '@material/snackbar';

CommonJS

const mdcSnackbar = require('mdc-snackbar');
const MDCSnackbar = mdcSnackbar.MDCSnackbar;
const MDCSnackbarFoundation = mdcSnackbar.MDCSnackbarFoundation;

AMD

require(['path/to/mdc-snackbar'], mdcSnackbar => {
  const MDCSnackbar = mdcSnackbar.MDCSnackbar;
  const MDCSnackbarFoundation = mdcSnackbar.MDCSnackbarFoundation;
});

Global

const MDCSnackbar = mdc.snackbar.MDCSnackbar;
const MDCSnackbarFoundation = mdc.snackbar.MDCSnackbarFoundation;

Automatic Instantiation

If you do not care about retaining the component instance for the snackbar, simply call attachTo() and pass it a DOM element.

mdc.snackbar.MDCSnackbar.attachTo(document.querySelector('.mdc-snackbar'));

Manual Instantiation

Snackbars can easily be initialized using their default constructors as well, similar to attachTo.

import {MDCSnackbar} from '@material/snackbar';

const snackbar = new MDCSnackbar(document.querySelector('.mdc-snackbar'));

Handling events

When snackbar is shown or dismissed, the component will emit a MDCSnackbar:show or MDCSnackbar:hide custom event with no data attached.

Showing a message and action

Once you have obtained an MDCSnackbar instance attached to the DOM, you can use the show method to trigger the display of a message with optional action. The show method takes an object for snackbar data. The table below shows the properties and their usage.

Property	Effect	Remarks	Type
message	The text message to display.	Required	String
timeout	The amount of time in milliseconds to show the snackbar.	Optional (default 2750)	Integer
actionHandler	The function to execute when the action is clicked.	Optional	Function
actionText	The text to display for the action button.	Required if actionHandler is set	String
multiline	Whether to show the snackbar with space for multiple lines of text	Optional	Boolean
actionOnBottom	Whether to show the action below the multiple lines of text	Optional, applies when multiline is true	Boolean

Responding to a Snackbar Action

To respond to a snackbar action, assign a function to the optional actionHandler property in the object that gets passed to the show method. If you choose to set this property, you must also set the actionText property.

<div class="mdc-snackbar"
     aria-live="assertive"
     aria-atomic="true"
     aria-hidden="true">
  <div class="mdc-snackbar__text"></div>
  <div class="mdc-snackbar__action-wrapper">
    <button type="button" class="mdc-snackbar__action-button"></button>
  </div>
</div>

import {MDCSnackbar} from '@material/snackbar';

const snackbar = new MDCSnackbar(document.querySelector('.mdc-snackbar'));
const dataObj = {
  message: messageInput.value,
  actionText: 'Undo',
  actionHandler: function () {
    console.log('my cool function');
  }
};

snackbar.show(dataObj);

Keep snackbar when the action button is pressed

By default the snackbar will be dimissed when the user presses the action button. If you want the snackbar to remain visible until the timeout is reached (regardless of whether the user pressed the action button or not) you can set the dismissesOnAction property to false:

const snackbar = new MDCSnackbar(document.querySelector('.mdc-snackbar'));
snackbar.dismissesOnAction = false

Using the Foundation Class

MDC Snackbar ships with an MDCSnackbarFoundation class that external frameworks and libraries can use to integrate the component. As with all foundation classes, an adapter object must be provided. The adapter for snackbars must provide the following functions, with correct signatures:

Method Signature	Description
addClass(className: string) => void	Adds a class to the root element.
removeClass(className: string) => void	Removes a class from the root element.
setAriaHidden() => void	Sets aria-hidden="true" on the root element.
unsetAriaHidden() => void	Removes the aria-hidden attribute from the root element.
setActionAriaHidden() => void	Sets aria-hidden="true" on the action element.
unsetActionAriaHidden() => void	Removes the aria-hidden attribute from the action element.
setActionText(actionText: string) => void	Set the text content of the action element.
setMessageText(message: string) => void	Set the text content of the message element.
setFocus() => void	Sets focus on the action button.
visibilityIsHidden() => boolean	Returns document.hidden property.
registerBlurHandler(handler: EventListener) => void	Registers an event handler to be called when a blur event is triggered on the action button
deregisterBlurHandler(handler: EventListener) => void	Deregisters a blur event handler from the actionButton
registerVisibilityChangeHandler(handler: EventListener) => void	Registers an event handler to be called when a 'visibilitychange' event occurs
deregisterVisibilityChangeHandler(handler: EventListener) => void	Deregisters an event handler to be called when a 'visibilitychange' event occurs
registerCapturedInteractionHandler(evtType: string, handler: EventListener) => void	Registers an event handler to be called when the given event type is triggered on the body
deregisterCapturedInteractionHandler(evtType: string, handler: EventListener) => void	Deregisters an event handler from the body
registerActionClickHandler(handler: EventListener) => void	Registers an event handler to be called when a click event is triggered on the action element.
deregisterActionClickHandler(handler: EventListener) => void	Deregisters an event handler from a click event on the action element. This will only be called with handlers that have previously been passed to registerActionClickHandler calls.
registerTransitionEndHandler(handler: EventListener) => void	Registers an event handler to be called when an transitionend event is triggered on the root element. Note that you must account for vendor prefixes in order for this to work correctly.
deregisterTransitionEndHandler(handler: EventListener) => void	Deregisters an event handler from an transitionend event listener. This will only be called with handlers that have previously been passed to registerTransitionEndHandler calls.
notifyShow() => void	Dispatches an event notifying listeners that the snackbar has been shown.
notifyHide() => void	Dispatches an event notifying listeners that the snackbar has been hidden.

Avoiding Flash-Of-Unstyled-Content (FOUC)

If you are loading the mdc-snackbar CSS asynchronously, you may experience a brief flash-of-unstyled-content (FOUC) due to the snackbar's translate transition running once the CSS loads. To avoid this temporary FOUC, you can add the following simple style before the mdc-snackbar CSS is loaded:

.mdc-snackbar { transform: translateY(100%); }

This will move the snackbar offscreen until the CSS is fully loaded and avoids a translate transition upon load.