Lion Web Components

Lion web components is a set of highly performant, accessible and flexible Web Components. They provide an unopinionated, white label layer that can be extended to your own layer of components.

For some more details see the announcement blog post.

Demos

We do have a live Storybook which shows all our components.

Please note: This project uses Yarn Workspaces. If you want to run all demos locally you need to get Yarn and install all depencies by executing yarn install.

How to install

npm i @lion/<package-name>

Content

The accessibility column indicates whether the functionality is accessible in its core. Aspects like styling and content determine actual accessibility in usage.

Package	Description	Accessibility
-- Buttons --
button	Button	✔️
switch	Switch	✔️
-- Forms --
form	Wrapper for multiple form elements	✔️
field	Base Class for all inputs	✔️
fieldset	Group for form inputs	✔️
validate	Validation for form components	n/a
checkbox	Checkbox form element	✔️
checkbox-group	Group of checkboxes	✔️
input	Input element for strings	✔️
input-amount	Input element for amounts	✔️
input-date	Input element for dates	✔️
input-datepicker	Input element for dates with a datepicker	✔️
input-email	Input element for e-mails	✔️
input-iban	Input element for IBANs	✔️
input-range	Input element for a range of values	✔️
radio	Radio from element	✔️
radio-group	Group of radios	✔️
select	Simple native dropdown element	✔️
textarea	Multiline text input	✔️
-- Overlays --
overlays	Overlay System	✔️
dialog	Dialog element	✔️
tooltip	Tooltip element	#175
-- Icons --
icon	Display our svg icons	#173, #172
-- Navigation --
steps	Multi Step System	n/a
tabs	Move between a small number of equally important views	n/a
-- Others --
core	Core System (exports LitElement, lit-html)	n/a
calendar	Standalone calendar	#195, #194
localize	Localize and translate your application/components	n/a
ajax	Fetching data via ajax request	n/a

How to use

Use a Web Component

<script type="module">
  import '@lion/input/lion-input.js';
</script>

<lion-input name="firstName"></lion-input>

Use a JavaScript system

<script type="module">
  import { ajax } from '@lion/ajax';

  ajax.get('data.json').then(response => {
    // most likely you will use response.data
  });
</script>

Extend a Web Component

import { LionInput } from '@lion/input';

class MyInput extends LionInput {}
customElements.define('my-input', MyInput);

Key Features

High Performance - Focused on great performance in all relevant browsers with a minimal number of dependencies
Accessibility - Aimed at compliance with the WCAG 2.0 AA standard to create components that are accessible for everybody
Flexibility - Provides solutions through Web Components and JavaScript classes which can be used, adopted and extended to fit all needs

Technologies

Lion Web Components aims to be future proof and use well-supported proven technology. The stack we have chosen should reflect this.

Rationale

We know from experience that making high quality, accessible UI components is hard and time consuming: it takes many iterations, a lot of development time and a lot of testing to get a generic component that works in every context, supports many edge cases and is accessible in all relevant screen readers.

Lion aims to do the heavy lifting for you. This means you only have to apply your own Design System: by delivering styles, configuring components and adding a minimal set of custom logic on top.

Coding guidlines

Check out our coding guidelines for more detailed information.

How to contribute

Lion Web Components are only as good as its contributions. Read our contribution guide and feel free to enhance/improve Lion. We keep feature requests closed while we're not working on them.

Contact

Feel free to create a github issue for any feedback or questions you might have. You can also find us on the Polymer slack in the #lion channel.

You can join the Polymer slack by visiting https://www.polymer-project.org/slack-invite.

Support and issues

As stated above "support and issues time" is currently rather limited: feel free to open a discussion. However, we can not guarantee any response times.

jeffreylzkong/lion