Package Exports

@material/snackbar
@material/snackbar/constants
@material/snackbar/dist/mdc.snackbar
@material/snackbar/dist/mdc.snackbar.css
@material/snackbar/foundation
@material/snackbar/foundation.js
@material/snackbar/index
@material/snackbar/mdc-snackbar.scss

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (@material/snackbar) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

Snackbars

Snackbars provide brief messages about app processes at the bottom of the screen.

Design & API Documentation

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.
`isFocused() => boolean`	Detects 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.