@polymer/iron-collapse


<iron-collapse>

iron-collapse creates a collapsible block of content. By default, the content
will be collapsed. Use opened or toggle() to show/hide the content. The
aria-expanded attribute should only be set on the button that controls the
collapsable area, not on the area itself. See
https://www.w3.org/WAI/GL/wiki/Using_aria-expanded_to_indicate_the_state_of_a_collapsible_element#Description

iron-collapse adjusts the max-height/max-width of the collapsible element to show/hide
the content. So avoid putting padding/margin/border on the collapsible directly,
and instead put a div inside and style that.

``html







`

$3

The following custom properties and mixins are available for styling:

| Custom property | Description | Default |
| --- | --- | --- |
| --iron-collapse-transition-duration | Animation transition duration | 300ms |

See: Documentation,
Demo.

Usage

$3


`
npm install --save @polymer/iron-collapse
`

$3

`html

Content goes here...

`

$3

`js
import {PolymerElement, html} from '@polymer/polymer';
import '@polymer/iron-collapse/iron-collapse.js';

class SampleElement extends PolymerElement {
static get template() {
return html

;
}
}
customElements.define('sample-element', SampleElement);
`

Contributing

If you want to send a PR to this element, here are
the instructions for running the tests and demo locally:

$3

`sh
git clone https://github.com/PolymerElements/iron-collapse
cd iron-collapse
npm install
npm install -g polymer-cli
`

$3

`sh
polymer serve --npm
open http://127.0.0.1:/demo/
`

$3

`sh
polymer test --npm
``