Bootstrap/docs/components/collapse.md

layout	title	group
docs	Collapse	components

The Bootstrap collapse plugin allows you to toggle content on your pages with a bit of JavaScript and some classes. Flexible plugin that utilizes a handful of classes (from the required [transitions plugin]({{ site.baseurl }}/components/transitions/)) for easy toggle behavior.

Contents

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Example

Click the buttons below to show and hide another element via class changes:

• .collapse hides content
• .collapsing is applied during transitions
• .collapse.in shows content

You can use a link with the href attribute, or a button with the data-target attribute. In both cases, the data-toggle="collapse" is required.

{% example html %}

Link with href Button with data-target

Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident.

{% endexample %}

Accordion example

Extend the default collapse behavior to create an accordion.

{% example html %}

Collapsible Group Item #1

Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.

Collapsible Group Item #2

Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.

Collapsible Group Item #3

Anim pariatur cliche reprehenderit, enim eiusmod high life accusamus terry richardson ad squid. 3 wolf moon officia aute, non cupidatat skateboard dolor brunch. Food truck quinoa nesciunt laborum eiusmod. Brunch 3 wolf moon tempor, sunt aliqua put a bird on it squid single-origin coffee nulla assumenda shoreditch et. Nihil anim keffiyeh helvetica, craft beer labore wes anderson cred nesciunt sapiente ea proident. Ad vegan excepteur butcher vice lomo. Leggings occaecat craft beer farm-to-table, raw denim aesthetic synth nesciunt you probably haven't heard of them accusamus labore sustainable VHS.

{% endexample %}

Accessibility

Be sure to add aria-expanded to the control element. This attribute explicitly defines the current state of the collapsible element to screen readers and similar assistive technologies. If the collapsible element is closed by default, it should have a value of aria-expanded="false". If you've set the collapsible element to be open by default using the in class, set aria-expanded="true" on the control instead. The plugin will automatically toggle this attribute based on whether or not the collapsible element has been opened or closed.

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.in shows the content
• .collapsing is added when the transition starts, and removed when it finishes

These classes can be found in _animation.scss.

Via data attributes

Just add data-toggle="collapse" and a data-target to the element to automatically assign control of a collapsible element. 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 in.

To add accordion-like group management to a collapsible control, 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	false	If a selector 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 panel class)
toggle	boolean	true	Toggles the collapsible element on invocation

Methods

.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.

.collapse('show')

Shows a collapsible element.

.collapse('hide')

Hides a collapsible element.

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 %}