Backtotop

<auro-backtotop> is a HTML custom element for the purpose of helping visitors quickly return to page top.

UI development browser support

For the most up to date information on UI development browser support

Install

$ npm i @alaskaairux/auro-backtotop

Installing as a direct, dev or peer dependency is up to the user installing the package. If you are unsure as to what type of dependency you should use, consider reading this stack overflow answer.

Design Token CSS Custom Property dependency

The use of any Auro custom element has a dependency on the Auro Design Tokens.

CSS Custom Property fallbacks

CSS custom properties are not supported in older browsers. For this, fallback properties are pre-generated and included with the npm.

Any update to the Auro Design Tokens will be immediately reflected with browsers that support CSS custom properties, legacy browsers will require updated components with pre-generated fallback properties.

Define dependency in project component

Defining the component dependency within each component that is using the <auro-backtotop> component.

import "@alaskaairux/auro-backtotop";

Reference component in HTML

<auro-backtotop></auro-backtotop>

Install bundled assets from CDN

In cases where the project is not able to process JS assets, there are pre-processed assets available for use. Two bundles are available -- auro-backtotop__bundled.js for modern browsers and auro-backtotop__bundled.es5.js for legacy browsers (including IE11).

Since the legacy bundle includes many polyfills that are not needed by modern browsers, we recommend you load these bundles using differential serving so that the browser only loads the bundle it needs. To accomplish this, the script tag for the modern bundle should have type="module" and the script tag for the legacy bundle should have the nomodule attribute. See the example below.

NOTE: Be sure to replace @latest in the URL with the version of the asset you want. @latest is NOT aware of any MAJOR releases, use at your own risk.

<link rel="stylesheet" href="https://unpkg.com/@alaskaairux/design-tokens@latest/dist/tokens/CSSCustomProperties.css" />
<link rel="stylesheet" href="https://unpkg.com/@alaskaairux/webcorestylesheets@latest/dist/bundled/essentials.css" />

<script src="https://unpkg.com/@alaskaairux/auro-backtotop@latest/dist/auro-backtotop__bundled.js" type="module"></script>
<script src="https://unpkg.com/@alaskaairux/auro-backtotop@latest/dist/auro-backtotop__bundled.es5.js" nomodule></script>

auro-backtotop use cases

The <auro-backtotop> element should be used in situations where users may:

informational pages with many sections
pages with infinite scroll

API Code Examples

Default (fixed positioning):

<auro-backtotop></auro-backtotop>

Adjust how soon or delayed the button shows either by where you include the element in your document or with the rootmargintop property:

<!-- delay showing the button by 120px -->
<auro-backtotop rootmargintop="120px"></auro-backtotop>

To display inline:

<auro-backtotop inline></auro-backtotop>

For i18n support:

<auro-backtotop arialabel="volver arriba">volver arriba</auro-backtotop>

You can customize what renders in the button:

<auro-backtotop inline arialabel="zoom back to top">zoom zoom! 🚀</auro-backtotop>

Development

In order to develop against this project, if you are not part of the core team, you will be required to fork the project prior to submitting a pull request.

Please be sure to review the contribution guidelines for this project. Please make sure to pay special attention to the conventional commits section of the document.

Start development environment

Once the project has been cloned to your local resource and you have installed all the dependencies you will need to open two different shell sessions. One is for the npm tasks, the second is to run the server.

// shell terminal one
$ npm run dev

// shell terminal two
$ npm run serve

Open localhost:8000

Testing

Automated tests are required for every Auro component. See .\test\auro-backtotop.test.js for the tests for this component. Run npm test to run the tests and check code coverage. Tests must pass and meet a certain coverage threshold to commit. See the testing documentation for more details.

Demo deployment

To deploy a demo version of the component for review, run npm run demo:build to create a ./build directory that can be pushed to any static server.

littleninja/auro-backtotop