Bootstrap collapse, callback after expand is complete

Question

I have a Bootstrap collapse panel in my webpage. I need to execute a function after the transition is complete and the panel has expanded fully. I have found this example for how to access the callback when the panel is collapsing and hidden.bs.collapse is added. How to trigger a JavaScript function after "Bootstrap: collapse plugin" transition is done.

But using similar code I can't seem to trigger when the .collapse.in class is applied.

$('#collapseExample').on('.collapse.in', function(){
    alert("hi");
 });

I also found this code using promises to trigger a function after a class is toggled. It is supposed to wait until all animations are complete. jquery function on toggleClass complete? This does not seem to work for my problem either.

So I ask: How do I trigger a function when the collapse function is done?

This snippet attempts the jQuery promise technique. Ideally it would add the class .red after the panel is done expanding but it triggers immediately. http://www.bootply.com/Vx9oeyYy03#

$(document).on('click', '.btn', function(){
    $('#collapseExample').collapse("toggle").promise().done(function () {
         $('.well').addClass('red');
    })
});

Answer 1

You can to use the shown event handler which will be triggered after the animation is completed

$('#collapseExample').on('shown.bs.collapse', function() {
  console.log("shown");
}).on('show.bs.collapse', function() {
  console.log("show");
});

<!-- Provides the `snippet` object, see http://meta.stackexchange.com/a/242144/134069 -->
<script src="http://tjcrowder.github.io/simple-snippets-console/snippet.js"></script>

<script type="text/javascript" src="//code.jquery.com/jquery-1.10.1.js"></script>
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.4/css/bootstrap.css" />
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.4/css/bootstrap-theme.css" />
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.4/js/bootstrap.js"></script>


<div id="collapseExample" class="panel-group" role="tablist" aria-multiselectable="true">
  <div class="panel panel-default">
    <div class="panel-heading" role="tab" id="headingOne">
      <h4 class="panel-title">
        <a role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseOne" aria-expanded="true" aria-controls="collapseOne">
          Collapsible Group Item #1
        </a>
      </h4>
    </div>
    <div id="collapseOne" class="panel-collapse collapse in" role="tabpanel" aria-labelledby="headingOne">
      <div class="panel-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="panel panel-default">
    <div class="panel-heading" role="tab" id="headingTwo">
      <h4 class="panel-title">
        <a class="collapsed" role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseTwo" aria-expanded="false" aria-controls="collapseTwo">
          Collapsible Group Item #2
        </a>
      </h4>
    </div>
    <div id="collapseTwo" class="panel-collapse collapse" role="tabpanel" aria-labelledby="headingTwo">
      <div class="panel-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="panel panel-default">
    <div class="panel-heading" role="tab" id="headingThree">
      <h4 class="panel-title">
        <a class="collapsed" role="button" data-toggle="collapse" data-parent="#accordion" href="#collapseThree" aria-expanded="false" aria-controls="collapseThree">
          Collapsible Group Item #3
        </a>
      </h4>
    </div>
    <div id="collapseThree" class="panel-collapse collapse" role="tabpanel" aria-labelledby="headingThree">
      <div class="panel-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>