Kolaps

Jak to funguje

Plugin JavaScript pro sbalení se používá k zobrazení a skrytí obsahu. Tlačítka nebo kotvy se používají jako spouštěče, které jsou mapovány na konkrétní prvky, které přepínáte. Sbalením prvku dojde k animaci prvku heightz jeho aktuální hodnoty na 0. Vzhledem k tomu, jak CSS zpracovává animace, nemůžete použít paddingna .collapseprvek. Místo toho použijte třídu jako nezávislý prvek obtékání.

Příklad

Kliknutím na tlačítka níže zobrazíte a skryjete další prvek prostřednictvím změn třídy:

• .collapseskrývá obsah
• .collapsingse aplikuje při přechodech
• .collapse.showzobrazuje obsah

Obecně doporučujeme použít tlačítko s data-bs-targetatributem. I když se to ze sémantického hlediska nedoporučuje, můžete také použít odkaz s hrefatributem (a role="button"). V obou případech data-bs-toggle="collapse"je požadováno.

<p>
  <a class="btn btn-primary" data-bs-toggle="collapse" href="#collapseExample" role="button" aria-expanded="false" aria-controls="collapseExample">
    Link with href
  </a>
  <button class="btn btn-primary" type="button" data-bs-toggle="collapse" data-bs-target="#collapseExample" aria-expanded="false" aria-controls="collapseExample">
    Button with data-bs-target
  </button>
</p>
<div class="collapse" id="collapseExample">
  <div class="card card-body">
    Some placeholder content for the collapse component. This panel is hidden by default but revealed when the user activates the relevant trigger.
  </div>
</div>

Horizontální

Zásuvný modul sbalení také podporuje horizontální sbalení. Přidejte .collapse-horizontaltřídu modifikátoru pro přechod na widthmísto heighta nastavte a widthna bezprostřední podřízený prvek. Neváhejte napsat svůj vlastní Sass, použijte inline styly nebo použijte naše nástroje pro šířku .

<p>
  <button class="btn btn-primary" type="button" data-bs-toggle="collapse" data-bs-target="#collapseWidthExample" aria-expanded="false" aria-controls="collapseWidthExample">
    Toggle width collapse
  </button>
</p>
<div style="min-height: 120px;">
  <div class="collapse collapse-horizontal" id="collapseWidthExample">
    <div class="card card-body" style="width: 300px;">
      This is some placeholder content for a horizontal collapse. It's hidden by default and shown when triggered.
    </div>
  </div>
</div>

Multiple targets

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

<p>
  <a class="btn btn-primary" data-bs-toggle="collapse" href="#multiCollapseExample1" role="button" aria-expanded="false" aria-controls="multiCollapseExample1">Toggle first element</a>
  <button class="btn btn-primary" type="button" data-bs-toggle="collapse" data-bs-target="#multiCollapseExample2" aria-expanded="false" aria-controls="multiCollapseExample2">Toggle second element</button>
  <button class="btn btn-primary" type="button" data-bs-toggle="collapse" data-bs-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="card card-body">
        Some placeholder content for the first collapse component of this multi-collapse example. This panel is hidden by default but revealed when the user activates the relevant trigger.
      </div>
    </div>
  </div>
  <div class="col">
    <div class="collapse multi-collapse" id="multiCollapseExample2">
      <div class="card card-body">
        Some placeholder content for the second collapse component of this multi-collapse example. This panel is hidden by default but revealed when the user activates the relevant trigger.
      </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 collapsible 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-bs-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 optional keyboard interactions described in the WAI-ARIA Authoring Practices 1.1 accordion pattern - you will need to include these yourself with custom JavaScript.

Sass

Variables

$transition-collapse:         height .35s ease;
$transition-collapse-width:   width .35s ease;

Classes

Collapse transition classes can be found in scss/_transitions.scss as these are shared across multiple components (collapse and accordion).

.collapse {
  &:not(.show) {
    display: none;
  }
}

.collapsing {
  height: 0;
  overflow: hidden;
  @include transition($transition-collapse);

  &.collapse-horizontal {
    width: 0;
    height: auto;
    @include transition($transition-collapse-width);
  }
}

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-bs-toggle="collapse" and a data-bs-target to the element to automatically assign control of one or more collapsible elements. The data-bs-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-bs-parent="#selector". Refer to the accordion page for more information.

Via JavaScript

Enable manually with:

var collapseElementList = [].slice.call(document.querySelectorAll('.collapse'))
var collapseList = collapseElementList.map(function (collapseEl) {
  return new bootstrap.Collapse(collapseEl)
})

Options

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

Methods

Activates your content as a collapsible element. Accepts an optional options object.

You can create a collapse instance with the constructor, for example:

var myCollapse = document.getElementById('myCollapse')
var bsCollapse = new bootstrap.Collapse(myCollapse, {
  toggle: false
})

Events

Bootstrap’s collapse class exposes a few events for hooking into collapse functionality.

var myCollapsible = document.getElementById('myCollapsible')
myCollapsible.addEventListener('hidden.bs.collapse', function () {
  // do something...
})