javascript - Sorting a list by data-attribute

Question

I have a list of people with job titles sorted by the persons’ first names, like this:

<ul>
  <li data-azsort="smithjohn">
    <a href="#">
      <span class="list-name">John Smith</span>
    </a>
    <span class="list-desc">Professor</span>
  </li>
  ..
  <li data-azsort="barnestom">
    <a href="#">
      <span class="list-name">Tom Barnes</span>
    </a>
    <span class="list-desc">Lecturer</span>
  </li>
</ul>

I’ve added the data-azsort attribute to the <li> element, and I’d like to pop these list elements into an array, and sort based on that data-* attribute (using plain JavaScript).

What would be the best way to sort the list by data-azsort (A-Z), returning the same code? JavaScript only, no jQuery, etc.

Answer 1

This works for any number of lists: it basically gathers all lis in uls that have your attribute, sorts them according to their data-* attribute value and re-appends them to their parent.

Array.from(document.querySelectorAll("ul > li[data-azsort]"))
  .sort(({dataset: {azsort: a}}, {dataset: {azsort: b}}) => a.localeCompare(b)) // To reverse it, use `b.localeCompare(a)`.
  .forEach((item) => item.parentNode.appendChild(item));

<ul>
  <li data-azsort="skeetjon">
    <a href="#"><span class="list-name">Jon Skeet</span></a>
    <span class="list-desc">Stack Overflow user</span>
  </li>
  <li data-azsort="smithjohn">
    <a href="#"><span class="list-name">John Smith</span></a>
    <span class="list-desc">Professor</span>
  </li>
  <li data-azsort="barnestom">
    <a href="#"><span class="list-name">Tom Barnes</span></a>
    <span class="list-desc">Lecturer</span>
  </li>
</ul>
<ul>
  <li data-azsort="smithjohn">
    <a href="#"><span class="list-name">John Smith</span></a>
    <span class="list-desc">Professor</span>
  </li>
  <li data-azsort="barnestom">
    <a href="#"><span class="list-name">Tom Barnes</span></a>
    <span class="list-desc">Lecturer</span>
  </li>
  <li data-azsort="skeetjon">
    <a href="#"><span class="list-name">Jon Skeet</span></a>
    <span class="list-desc">Stack Overflow user</span>
  </li>
</ul>