import { Meta, Story, Primary, Controls } from "@storybook/addon-docs";

import * as stories from "./button.stories";

<Meta of={stories} />

# Button

Buttons are interactive elements that can be triggered using a mouse, keyboard, or touch. They are
used to indicate actions that can be performed by a user such as submitting a form.

<Primary />

<Controls />

## Guidelines

### Choosing the `<a>` or `<button>`

Buttons can use either the `<a>` or `<button>` tags. Choose which based on the action the button
takes:

- If navigating to a new page, use `<a>`
- If taking an action on the current page use `<button>`
- If the button launches a dialog, use `<button>`

### Groups

Groups of buttons should be seperated by a `0.5` rem gap. Usually acomplished by using the
`tw-gap-2` class in the button group container.

Groups within page content, dialog footers or forms should have the `primary` call to action placed
to left. Groups in headers and navigational areas should have the `primary` call to action on the
right.

## Styles

There are 3 main styles for the button: Primary, Secondary, and Danger.

### Primary

<Story of={stories.Primary} />

Use the primary button styling for all Primary call to actions. An action is "primary" if it relates
to the main purpose of a page. There should never be 2 primary styled buttons next to each other.

### Secondary

<Story of={stories.Secondary} />

The secondary styling should be used for secondary calls to action. An action is "secondary" if it
relates indirectly to the purpose of a page. There may be multiple secondary buttons next to each
other; however, generally there should only be 1 or 2 calls to action per page.

### Danger

<Story of={stories.Danger} />

Use the danger styling only in settings when the user may preform a permanent action.

## Disabled UI

Both the disabled and loading states use the default state’s color with a 60% opacity or
`tw-opacity-60`.

<Story of={stories.Disabled} />

## Block

Typically button widths expand with their text. In some causes though buttons may need to be block
where the width is fixed and the text wraps to 2 lines if exceeding the button’s width.

<Story of={stories.Block} />

## Accessibility

Please follow these guidelines to ensure that buttons are accessible to all users.

### Color contrast

All button styles are WCAG compliant when displayed on `background` and `background-alt` colors. To
use a button on a different background, double check that the color contrast is sufficient in both
the light and dark themes.

### Loading Buttons

Include an `aria-label` attribute that defaults to "loading" but can be configurable per
implementation. On click, the screen reader should announce the `aria-label`. Once the action is
completed, use another messaging pattern to alert the user that the action is complete (example:
success toast).

### Submit and async actions

Both submit and async action buttons use a loading button state while an action is taken. If your
button is preforming a long running task in the background like a server API call, be sure to review
the [Async Actions Directive](?path=/story/component-library-async-actions-overview--page).

<Story of={stories.Loading} />

### appA11yTitle

`appA11yTitle` is a directive that auto assigns the same string to the `title` and `aria-label`
attributes.

When a button uses accessible content (e.i. actual text), DO NOT include this as it adds redundant
content for someone using assistive technology.

`appA11yTitle` should only be used if the element it applies to does not include accessible text,
e.i. an icon.
