Replicating jQuery slideToggle without jQuery

Question

Since Anki doesn't support jQuery, how would I go about converting the jQuery on this particular document so that the same effects are produced in vanilla JS, or purely in CSS3 (specifically of the + button, and when clicking on list items)?

Answer 1

You can use css transitions for that. E.g:

.pronunciation, li dl {
  overflow: hidden;
  transition: height .3s linear;
}
.hidden {
  height: 0!important;
}

Take a look at the code below (same logic as yours, but converted to vanilla Javascript and CSS3):

document.addEventListener('DOMContentLoaded', function() {
  var show = document.getElementById('show-pronunciation');
  var pron = document.querySelector('.pronunciation');
  
  pron.style.height = pron.clientHeight + 'px';
  pron.classList.add('hidden');  
  show.addEventListener('click', function(e) {
    pron.classList.toggle('hidden');
  });
  
  [].forEach.call(document.querySelectorAll('li'), function(el, i) {
    var dl = el.querySelector('dl');
    dl.style.height = dl.clientHeight + 'px';
    
    el.addEventListener('click', function() {
      dl.classList.toggle('hidden');
    });
  });  
});

body {
  font-family: Avenir, Futura, sans-serif;
  background-color: #f7f7f7;
}
.definitions dl {
  border-left: 2px solid #ff1919;
  padding-left: 5px;
}
dt {
  font-weight: bold;
}
dd {
  margin-left: 1em;
}
.main {
  margin: 20px 20px 0 20px;
  border: transparent;
  border-radius: 5px;
  /*padding: 15px 10px 5px 10px;*/
  border-collapse: collapse;
  background-color: #FF4C4C;
  padding-bottom: 5px;
}
.header {
  border-radius: 5px;
  padding: 5px;
  background-color: white;
}
.content {
  margin: 5px 5px 0px 5px;
  border: transparent;
  border-top: none;
  border-radius: 5px;
  padding: 5px;
  background-color: #FCE8E8;
}
.info {
  clear: both;
  padding: 5px;
  display: block;
}
.grammatical-info {
  display: inline-block;
  border: transparent;
  border-radius: 5px;
  float: left;
  padding: 3px;
  background: deepskyblue;
  color: white;
}
.level {
  display: inline-block;
  border: transparent;
  border-radius: 5px;
  float: right;
  padding: 3px;
  background: crimson;
  color: white;
}
.foreign-word {
  display: inline-block;
  border: transparent;
  position: relative;
  font-size: 20pt;
}
.pronunciation {
  overflow: auto;
  border: transparent;
  border-radius: 10px;
  background-color: white;
  font-size: 8pt;
  position: absolute;
  left: -2px;
  bottom: 40px;
  width: 100%;
  text-align: center;
}
.btn {
  font-size: 20pt;
  background-color: transparent;
  border: none;
  border-radius: 28px;
  cursor: pointer;
  text-decoration: none;
  text-shadow: none;
  display: inline-block;
  color: #999;
}
.btn:hover {
  color: #aaa;
}
.btn:active {
  color: #ccc;
}
#play-sound {
  float: right;
}

.pronunciation, li dl {
  overflow: hidden;
  transition: height .3s linear;
}
.hidden {
  height: 0!important;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
<div class="main">
  <div class="header">
    <button class="btn" id="show-pronunciation">+</button>
    <div class="foreign-word">
      制造
      <div class="pronunciation">
        zhì zào
      </div>
    </div>
    <button class="btn" id="play-sound">
      <img src="http://uxrepo.com/static/icon-sets/elusive/svg/volume.svg" height="20px" />
    </button>
  </div>
  <div class="info">
    <span class="grammatical-info">动 verb</span>
    <span class="level">三</span>
  </div>
  <br/>
  <div class="content">

    <div class="definitions">
      <ol>
        <li>
          manufacture
          <dl>
            <dt>中国制造</dt>
            <dd>Made in China</dd>
          </dl>
        </li>
        <li>
          create
          <dl>
            <dt>制造假象</dt>
            <dd>put up a false front</dd>
            <dt>制造紧张局势</dt>
            <dd>create tension</dd>
            <dt>制造麻烦</dt>
            <dd>make trouble</dd>
          </dl>
        </li>
      </ol>
    </div>
  </div>
</div>