import {ExampleCodeBlock, SymbolDoc} from '@workday/canvas-kit-docs';

import StartIcon from './examples/StartIcon';
import EndIcon from './examples/EndIcon';
import Avatar from './examples/Avatar';
import Depth from './examples/Depth';
import RTL from './examples/RTL';
import LongTitle from './examples/LongTitle';
import HoistedModel from './examples/HoistedModel';


# Canvas Kit Expandable

`Expandable` is a compound component that creates a header to expand or collapse related content.

## Installation

```sh
yarn add @workday/canvas-kit-react
```

## Usage

### Start Icon

For a basic expandable container with a chevron icon before the title, place`Expandable.Icon` before
`Expandable.Title` as children of `Expandable.Target` and pass the `iconPosition` prop to
`Expandable.Icon` with a value of `start`. `Expandable.Icon` will use a right chevron icon when
collapsed and a down chevron icon when expanded.

<ExampleCodeBlock code={StartIcon} />

### End Icon

For an expandable container with a chevron icon after the title, place `Expandable.Title` before
`Expandable.Icon` as children of `Expandable.Target` and pass the `iconPosition` prop to
`Expandable.Icon` with a value of `end`. `Expandable.Icon` will use a down chevron icon when
collapsed and an up chevron icon when expanded.

<ExampleCodeBlock code={EndIcon} />

### With Avatar

To include an avatar image, `Expandable.Avatar` should be placed between `Expandable.Icon` and
`Expandable.Title`. An `iconPosition` prop with a value of either `start` or `end` should be passed
to `Expandable.Icon` depending on whether the `Expandable.Icon` is placed before or after
`Expandable.Title`.

<ExampleCodeBlock code={Avatar} />

> **Accessibility Note:** In this situation, the Avatar is decorative and should not be announced to
> screen readers. The `<Expandable.Avatar>` component has `isDecorative` set to `true` by default to
> hide it from screen readers, as avatars in expandable headers are typically decorative when paired
> with adjacent text.

### Right to Left (RTL)

Expandable container has bidirectional support and should function as expected with RTL languages as
long as the content direction is set in your Canvas theme.

<ExampleCodeBlock code={RTL} />

### Depth

The `depth` prop passed to `Expandable` allows you to adjust the visual elevation of a component
using our depth tokens.

<ExampleCodeBlock code={Depth} />

### Title Wrap

Long titles will wrap to the next line and increase the height of the container.

<ExampleCodeBlock code={LongTitle} />

You can also have direct access to the model if

### Hoisted Model

If you need direct access to the model, you can hoist it with the `useExpandableModel` hook. In the
example below, we're hoisting the models to expand and collapse all three containers at once.

<ExampleCodeBlock code={HoistedModel} />

> **Accessibility Note:** When using multiple Expandable Containers on a page, use the `as` prop to
> render the `<Expandable.Content>` sub-component as an HTML `<section>` element. Then, use
> `aria-labelledby` to reference the unique `id` of the `<Expandable.Title>` element. This practice
> can be useful to screen reader users when multiple Expandable Containers are opened at one time
> for uniquely describing the boundaries of the expandable content.

## Accessibility

Our Expandable component renders a semantic HTML `<button>` element to the DOM, with an optional
parent heading element as defined by the `headingLevel` prop. The `aria-expanded` property is
included on the button to indicate the state of the content to screen readers.

[Accordion Pattern | APG | WAI | W3C](https://www.w3.org/WAI/ARIA/apg/patterns/accordion/)

- Use the `headingLevel` prop to assign an appropriate heading level based on the context of the
  page content.
- When using Expandable Container for navigation elements, then we don't recommend using the
  `headingLevel` prop. This will render only expandable buttons to the DOM, reserving headings for
  organizing content in the main body of the page.
- The `as` prop may also be used on `<Expandable.Content>` to render an HTML `<ul>` element for
  displaying a list of items. For example, check out
  [Side Panel with Navigation](https://workday.github.io/canvas-kit/?path=/docs/guides-accessibility-examples-side-panel-navigation--docs).

### Navigation

- **Tab key**: Moves focus to the next expandable button or focusable element
- **Shift + Tab**: Moves focus to the previous focusable element
- **Enter or Space**: Toggles the expanded/collapsed state

### Screen Reader Experience

- The expandable button will be announced with its title text followed by the button role
- The current state will be announced as either "collapsed" or "expanded" (For example: "Usage
  Guidance, button, collapsed" or "Usage Guidance, button, expanded")
- **State Changes:** When activating the button to expand content, screen readers will announce the
  new "expanded" state and vice versa when collapsing content.
- **Content Regions:** Screen reader users can use landmark navigation to jump between sections and
  each section will be announced with its associated title (For example: "Usage Guidance, landmark
  region")
- **Heading Structure:** Using heading levels with expandable buttons allows screen reader users to
  navigate by headings, making the document structure and hierarchy easier to understand.

## Component API

<SymbolDoc name="Expandable" fileName="/react/" />