Collapse

Toggle the visibility of content across your project with a few classes and our JavaScript plugins.

## How it works

The collapse JavaScript plugin is used to show and hide content. Buttons or anchors are used as triggers that are mapped to specific elements you toggle. Collapsing an element will animate the `height` from it's current value to `0`. Given how CSS handles animations, you cannot use `padding` on a `.collapse` element. Instead, use the class as an independent wrapping element.

## Example

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

- `.collapse` hides content
- `.collapsing` is applied during transitions
- `.collapse.show` 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.

Link with href

This is where we sit down, grab a cup of coffee and dial in the details. Understanding the task at hand and ironing out the wrinkles is key.

      <p>
        <a class="btn btn-primary" data-toggle="collapse" href="#collapseExample" role="button" aria-expanded="false" aria-controls="collapseExample">
          Link with href
        </a>
        <button class="btn btn-primary" type="button" data-toggle="collapse" data-target="#collapseExample" aria-expanded="false" aria-controls="collapseExample">
          Button with data-target
        </button>
      </p>
      <div class="collapse" id="collapseExample">
        <div class="bg-white p-4">
          This is where we sit down, grab a cup of coffee and dial in the details. Understanding the task at hand and ironing out the wrinkles is key.
        </div>
      </div>

## Multiple targets

A `<button>` or `<a>` can show and hide multiple elements by referencing them with a JQuery selector in its `href` or `data-target` attribute. Multiple `<button>` or `<a>` can show and hide an element if they each reference it with their `href` or `data-target` attribute

Toggle first element

This is where we sit down, grab a cup of coffee and dial in the details. Understanding the task at hand and ironing out the wrinkles is key.
This is where we sit down, grab a cup of coffee and dial in the details. Understanding the task at hand and ironing out the wrinkles is key.

      <p>
        <a class="btn btn-primary" data-toggle="collapse" href="#multiCollapseExample1" role="button" aria-expanded="false" aria-controls="multiCollapseExample1">Toggle first element</a>
        <button class="btn btn-primary" type="button" data-toggle="collapse" data-target="#multiCollapseExample2" aria-expanded="false" aria-controls="multiCollapseExample2">Toggle second element</button>
        <button class="btn btn-primary" type="button" data-toggle="collapse" data-target=".multi-collapse" aria-expanded="false" aria-controls="multiCollapseExample1 multiCollapseExample2">Toggle both elements</button>
      </p>
      <div class="row">
        <div class="col">
          <div class="collapse multi-collapse" id="multiCollapseExample1">
            <div class="bg-white p-4">
              This is where we sit down, grab a cup of coffee and dial in the details. Understanding the task at hand and ironing out the wrinkles is key.
            </div>
          </div>
        </div>
        <div class="col">
          <div class="collapse multi-collapse" id="multiCollapseExample2">
            <div class="bg-white p-4">
              This is where we sit down, grab a cup of coffee and dial in the details. Understanding the task at hand and ironing out the wrinkles is key.
            </div>
          </div>
        </div>
      </div>

## Accordion example

Also you can extend the default collapse behavior to create an accordion.

##### Do you have any built-in caching?

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.

##### Can I add/upgrade my plan at any time?

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.

##### What access comes with my hosting plan?

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.

      <div id="borderedAccordion">
        <div class="accordion accordion-bordered-y accordion-stacked">
          <header id="borderedAccordion-heading-1" class="accordion-header" aria-expanded="true" aria-controls="borderedAccordion-1"
                  data-toggle="collapse"
                  data-target="#borderedAccordion-1">
            <i class="gd-folder accordion-icon icon-text mr-2"></i>
            <h5 class="mb-0">Do you have any built-in caching?</h5>
            <i class="accordion-control gd-angle-down icon-text ml-auto"></i>
          </header>

          <div id="borderedAccordion-1" class="collapse show" aria-labelledby="borderedAccordion-heading-1"
               data-parent="#borderedAccordion">
            <div class="accordion-body">
              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.
            </div>
          </div>
        </div>

        <div class="accordion accordion-bordered-y accordion-stacked">
          <header id="borderedAccordion-heading-2" class="accordion-header collapsed" aria-expanded="false" aria-controls="borderedAccordion-2"
                  data-toggle="collapse"
                  data-target="#borderedAccordion-2">
            <i class="gd-folder accordion-icon icon-text mr-2"></i>
            <h5 class="mb-0">Can I add/upgrade my plan at any time?</h5>
            <i class="accordion-control gd-angle-down icon-text ml-auto"></i>
          </header>

          <div id="borderedAccordion-2" class="collapse" aria-labelledby="borderedAccordion-heading-2"
               data-parent="#borderedAccordion">
            <div class="accordion-body">
              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.
            </div>
          </div>
        </div>

        <div class="accordion accordion-bordered-y accordion-stacked">
          <header id="borderedAccordion-heading-3" class="accordion-header collapsed" aria-expanded="false" aria-controls="borderedAccordion-3"
                  data-toggle="collapse"
                  data-target="#borderedAccordion-3">
            <i class="gd-folder accordion-icon icon-text mr-2"></i>
            <h5 class="mb-0">What access comes with my hosting plan?</h5>
            <i class="accordion-control gd-angle-down icon-text ml-auto"></i>
          </header>

          <div id="borderedAccordion-3" class="collapse" aria-labelledby="borderedAccordion-heading-3"
               data-parent="#borderedAccordion">
            <div class="accordion-body">
              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.
            </div>
          </div>
        </div>
      </div>

## Accessibility

Be sure to add `aria-expanded` to the control element. This attribute explicitly conveys the current state of the collapsible element tied to the control to screen readers and similar assistive technologies. If the collapsible element is closed by default, the attribute on the control element should have a value of `aria-expanded="false"`. If you've set the collapsible element to be open by default using the `show` class, set `aria-expanded="true"` on the control instead. The plugin will automatically toggle this attribute on the control based on whether or not the collapsible element has been opened or closed (via JavaScript, or because the user triggered another control element also tied to the same collapsbile element). If the control element's HTML element is not a button (e.g., an `<a>` or `<div>`), 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 - 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 `assets/vendor/bootstrap/scss/_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.

## JavaScript behavior

For more information, see the official Bootstrap documentation.