`), the attribute `role="button"` should be added to the element.
If your control element is targeting a single collapsible element – i.e. the `data-target` attribute is pointing to an `id` selector – you should add the `aria-controls` attribute to the control element, containing the `id` of the collapsible element. Modern screen readers and similar assistive technologies make use of this attribute to provide users with additional shortcuts to navigate directly to the collapsible element itself.
Note that Bootstrap's current implementation does not cover the various keyboard interactions described in the [WAI-ARIA Authoring Practices 1.1 accordion pattern](https://www.w3.org/TR/wai-aria-practices-1.1/#accordion) - you will need to include these yourself with custom JavaScript.
## Usage
The collapse plugin utilizes a few classes to handle the heavy lifting:
- `.collapse` hides the content
- `.collapse.show` shows the content
- `.collapsing` is added when the transition starts, and removed when it finishes
These classes can be found in `_transitions.scss`.
### Via data attributes
Just add `data-toggle="collapse"` and a `data-target` to the element to automatically assign control of one or more collapsible elements. The `data-target` attribute accepts a CSS selector to apply the collapse to. Be sure to add the class `collapse` to the collapsible element. If you'd like it to default open, add the additional class `show`.
To add accordion-like group management to a collapsible area, add the data attribute `data-parent="#selector"`. Refer to the demo to see this in action.
### Via JavaScript
Enable manually with:
{% highlight js %}
$('.collapse').collapse()
{% endhighlight %}
### Options
Options can be passed via data attributes or JavaScript. For data attributes, append the option name to `data-`, as in `data-parent=""`.
| Name |
Type |
Default |
Description |
| parent |
selector | jQuery object | DOM element |
false |
If parent is provided, then all collapsible elements under the specified parent will be closed when this collapsible item is shown. (similar to traditional accordion behavior - this is dependent on the card class). The attribute has to be set on the target collapsible area. |
| toggle |
boolean |
true |
Toggles the collapsible element on invocation |
### Methods
{% capture callout-include %}{% include callout-danger-async-methods.md %}{% endcapture %}
{{ callout-include | markdownify }}
#### `.collapse(options)`
Activates your content as a collapsible element. Accepts an optional options `object`.
{% highlight js %}
$('#myCollapsible').collapse({
toggle: false
})
{% endhighlight %}
#### `.collapse('toggle')`
Toggles a collapsible element to shown or hidden. **Returns to the caller before the collapsible element has actually been shown or hidden** (i.e. before the `shown.bs.collapse` or `hidden.bs.collapse` event occurs).
#### `.collapse('show')`
Shows a collapsible element. **Returns to the caller before the collapsible element has actually been shown** (i.e. before the `shown.bs.collapse` event occurs).
#### `.collapse('hide')`
Hides a collapsible element. **Returns to the caller before the collapsible element has actually been hidden** (i.e. before the `hidden.bs.collapse` event occurs).
#### `.collapse('dispose')`
Destroys an element's collapse.
### Events
Bootstrap's collapse class exposes a few events for hooking into collapse functionality.
| Event Type |
Description |
| show.bs.collapse |
This event fires immediately when the show instance method is called. |
| shown.bs.collapse |
This event is fired when a collapse element has been made visible to the user (will wait for CSS transitions to complete). |
| hide.bs.collapse |
This event is fired immediately when the hide method has been called. |
| hidden.bs.collapse |
This event is fired when a collapse element has been hidden from the user (will wait for CSS transitions to complete). |
{% highlight js %}
$('#myCollapsible').on('hidden.bs.collapse', function () {
// do something…
})
{% endhighlight %}