`), the attribute `role="button"` should be added to the element.
Additionally, if your control element is targeting a single collapsible element – i.e. the `data-target` attribute is pointing to an `id` selector – you may add an additional `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.
## 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 %}