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[ipfire.org.git] / src / scss / bootstrap-4.0.0-alpha.6 / docs / components / carousel.md

---
layout: docs
title: Carousel
description: A slideshow component for cycling through elements—images or slides of text—like a carousel.
group: components
---

The carousel is a slideshow for cycling through a series of content, built with CSS 3D transforms and a bit of JavaScript. It works with a series of images, text, or custom markup. It also includes support for previous/next controls and indicators.

In browsers where the [Page Visibility API](https://www.w3.org/TR/page-visibility/) is supported, the carousel will avoid sliding when the webpage is not visible to the user (such as when the browser tab is inactive, the browser window is minimized, etc.).

Please be aware that nested carousels are not supported, and carousels are generally not compliant with accessibility standards.

## Contents

* Will be replaced with the ToC, excluding the "Contents" header
{:toc}

## Example

Carousels don't automatically normalize slide dimensions. As such, you may need to use additional utilities or custom styles to appropriately size content. While carousels support previous/next controls and indicators, they're not explicitly required. Add and customize as you see fit.

Be sure to set a unique id on the `.carousel` for optional controls, especially if you're using multiple carousels on a single page.

### Slides only

Here's a carousel with slides only. Note the presence of the `.d-block` and `.img-fluid` on carousel images to prevent browser default image alignment.

{% example html %}
<div id="carouselExampleSlidesOnly" class="carousel slide" data-ride="carousel">
  <div class="carousel-inner" role="listbox">
    <div class="carousel-item active">
      <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=777&fg=555&text=First slide" alt="First slide">
    </div>
    <div class="carousel-item">
      <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=666&fg=444&text=Second slide" alt="Second slide">
    </div>
    <div class="carousel-item">
      <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=555&fg=333&text=Third slide" alt="Third slide">
    </div>
  </div>
</div>
{% endexample %}

### With controls

Adding in the previous and next controls:

{% example html %}
<div id="carouselExampleControls" class="carousel slide" data-ride="carousel">
  <div class="carousel-inner" role="listbox">
    <div class="carousel-item active">
      <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=777&fg=555&text=First slide" alt="First slide">
    </div>
    <div class="carousel-item">
      <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=666&fg=444&text=Second slide" alt="Second slide">
    </div>
    <div class="carousel-item">
      <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=555&fg=333&text=Third slide" alt="Third slide">
    </div>
  </div>
  <a class="carousel-control-prev" href="#carouselExampleControls" role="button" data-slide="prev">
    <span class="carousel-control-prev-icon" aria-hidden="true"></span>
    <span class="sr-only">Previous</span>
  </a>
  <a class="carousel-control-next" href="#carouselExampleControls" role="button" data-slide="next">
    <span class="carousel-control-next-icon" aria-hidden="true"></span>
    <span class="sr-only">Next</span>
  </a>
</div>
{% endexample %}

### With indicators

You can also add the indicators to the carousel, alongside the controls, too.

{% example html %}
<div id="carouselExampleIndicators" class="carousel slide" data-ride="carousel">
  <ol class="carousel-indicators">
    <li data-target="#carouselExampleIndicators" data-slide-to="0" class="active"></li>
    <li data-target="#carouselExampleIndicators" data-slide-to="1"></li>
    <li data-target="#carouselExampleIndicators" data-slide-to="2"></li>
  </ol>
  <div class="carousel-inner" role="listbox">
    <div class="carousel-item active">
      <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=777&fg=555&text=First slide" alt="First slide">
    </div>
    <div class="carousel-item">
      <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=666&fg=444&text=Second slide" alt="Second slide">
    </div>
    <div class="carousel-item">
      <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=555&fg=333&text=Third slide" alt="Third slide">
    </div>
  </div>
  <a class="carousel-control-prev" href="#carouselExampleIndicators" role="button" data-slide="prev">
    <span class="carousel-control-prev-icon" aria-hidden="true"></span>
    <span class="sr-only">Previous</span>
  </a>
  <a class="carousel-control-next" href="#carouselExampleIndicators" role="button" data-slide="next">
    <span class="carousel-control-next-icon" aria-hidden="true"></span>
    <span class="sr-only">Next</span>
  </a>
</div>
{% endexample %}

{% callout warning %}
#### Initial active element required

The `.active` class needs to be added to one of the slides. Otherwise, the carousel will not be visible.
{% endcallout %}

### With captions

Add captions to your slides easily with the `.carousel-caption` element within any `.carousel-item`. They can be easily hidden on smaller viewports, as shown below, with optional [display utilities]({{ site.baseurl }}/utilities/display-property/). We hide them initially with `.d-none` and bring them back on medium-sized devices with `.d-md-block`.

<div class="bd-example">
  <div id="carouselExampleCaptions" class="carousel slide" data-ride="carousel">
    <ol class="carousel-indicators">
      <li data-target="#carouselExampleCaptions" data-slide-to="0" class="active"></li>
      <li data-target="#carouselExampleCaptions" data-slide-to="1"></li>
      <li data-target="#carouselExampleCaptions" data-slide-to="2"></li>
    </ol>
    <div class="carousel-inner" role="listbox">
      <div class="carousel-item active">
        <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=777&fg=555&text=First slide" alt="First slide">
        <div class="carousel-caption d-none d-md-block">
          <h3>First slide label</h3>
          <p>Nulla vitae elit libero, a pharetra augue mollis interdum.</p>
        </div>
      </div>
      <div class="carousel-item">
        <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=666&fg=444&text=Second slide" alt="Second slide">
        <div class="carousel-caption d-none d-md-block">
          <h3>Second slide label</h3>
          <p>Lorem ipsum dolor sit amet, consectetur adipiscing elit.</p>
        </div>
      </div>
      <div class="carousel-item">
        <img class="d-block img-fluid" data-src="holder.js/800x400?auto=yes&bg=555&fg=333&text=Third slide" alt="Third slide">
        <div class="carousel-caption d-none d-md-block">
          <h3>Third slide label</h3>
          <p>Praesent commodo cursus magna, vel scelerisque nisl consectetur.</p>
        </div>
      </div>
    </div>
    <a class="carousel-control-prev" href="#carouselExampleCaptions" role="button" data-slide="prev">
      <span class="carousel-control-prev-icon" aria-hidden="true"></span>
      <span class="sr-only">Previous</span>
    </a>
    <a class="carousel-control-next" href="#carouselExampleCaptions" role="button" data-slide="next">
      <span class="carousel-control-next-icon" aria-hidden="true"></span>
      <span class="sr-only">Next</span>
    </a>
  </div>
</div>

{% highlight html %}
<div class="carousel-item">
  <img src="..." alt="...">
  <div class="carousel-caption d-none d-md-block">
    <h3>...</h3>
    <p>...</p>
  </div>
</div>
{% endhighlight %}

## Usage

### Via data attributes

Use data attributes to easily control the position of the carousel. `data-slide` accepts the keywords `prev` or `next`, which alters the slide position relative to its current position. Alternatively, use `data-slide-to` to pass a raw slide index to the carousel `data-slide-to="2"`, which shifts the slide position to a particular index beginning with `0`.

The `data-ride="carousel"` attribute is used to mark a carousel as animating starting at page load. **It cannot be used in combination with (redundant and unnecessary) explicit JavaScript initialization of the same carousel.**

### Via JavaScript

Call carousel manually with:

{% highlight js %}
$('.carousel').carousel()
{% endhighlight %}

### Options

Options can be passed via data attributes or JavaScript. For data attributes, append the option name to `data-`, as in `data-interval=""`.

<table class="table table-bordered table-striped table-responsive">
  <thead>
   <tr>
     <th style="width: 100px;">Name</th>
     <th style="width: 50px;">Type</th>
     <th style="width: 50px;">Default</th>
     <th>Description</th>
   </tr>
  </thead>
  <tbody>
   <tr>
     <td>interval</td>
     <td>number</td>
     <td>5000</td>
     <td>The amount of time to delay between automatically cycling an item. If false, carousel will not automatically cycle.</td>
   </tr>
   <tr>
     <td>keyboard</td>
     <td>boolean</td>
     <td>true</td>
     <td>Whether the carousel should react to keyboard events.</td>
   </tr>
   <tr>
     <td>pause</td>
     <td>string | null</td>
     <td>"hover"</td>
     <td>If set to <code>"hover"</code>, pauses the cycling of the carousel on <code>mouseenter</code> and resumes the cycling of the carousel on <code>mouseleave</code>. If set to <code>null</code>, hovering over the carousel won't pause it.</td>
   </tr>
   <tr>
     <td>ride</td>
     <td>string</td>
     <td>false</td>
     <td>Autoplays the carousel after the user manually cycles the first item. If "carousel", autoplays the carousel on load.</td>
   </tr>
   <tr>
     <td>wrap</td>
     <td>boolean</td>
     <td>true</td>
     <td>Whether the carousel should cycle continuously or have hard stops.</td>
   </tr>
  </tbody>
</table>

### Methods

#### `.carousel(options)`

Initializes the carousel with an optional options `object` and starts cycling through items.

{% highlight js %}
$('.carousel').carousel({
  interval: 2000
})
{% endhighlight %}

#### `.carousel('cycle')`

Cycles through the carousel items from left to right.

#### `.carousel('pause')`

Stops the carousel from cycling through items.

#### `.carousel(number)`

Cycles the carousel to a particular frame (0 based, similar to an array).

#### `.carousel('prev')`

Cycles to the previous item.

#### `.carousel('next')`

Cycles to the next item.

### Events

Bootstrap's carousel class exposes two events for hooking into carousel functionality. Both events have the following additional properties:

- `direction`: The direction in which the carousel is sliding (either `"left"` or `"right"`).
- `relatedTarget`: The DOM element that is being slid into place as the active item.

All carousel events are fired at the carousel itself (i.e. at the `<div class="carousel">`).

<table class="table table-bordered table-striped table-responsive">
  <thead>
   <tr>
     <th style="width: 150px;">Event Type</th>
     <th>Description</th>
   </tr>
  </thead>
  <tbody>
   <tr>
     <td>slide.bs.carousel</td>
     <td>This event fires immediately when the <code>slide</code> instance method is invoked.</td>
   </tr>
   <tr>
     <td>slid.bs.carousel</td>
     <td>This event is fired when the carousel has completed its slide transition.</td>
   </tr>
  </tbody>
</table>

{% highlight js %}
$('#myCarousel').on('slide.bs.carousel', function () {
  // do something…
})
{% endhighlight %}