Docsy - Keep Sidebar Menu's Scroll Position

Docsy and many other Hugo themes have the same UI issue. Here is a solution.

The Issue

I'll save my time describing the issue. Just read the following Docsy issues on GitHub:

Both issues are created in 2020. They remain unresolved while I'm writing this note right now, and it is August 2023!

How I Solve It

Note the following solution can only be applied to Hugo with Docsy theme.

First, add a file body-end.html in the folder /layouts/partials/hooks/ of your website. This is a customization mechanism provided by Docsy theme.

Then add the following code to body-end.html:

<script > 
  (function() {
    var a = document.querySelector("#td-section-nav");
    addEventListener("beforeunload", function(b) {
        localStorage.setItem("menu.scrollTop", a.scrollTop)
    }), a.scrollTop = localStorage.getItem("menu.scrollTop")
  })()
</script>

Job done.

One final note: the id td-section-nav is a nav element used in Docsy for the sidebar menu. You can find this element with Chrome DevTools. It looks like:

<nav class="collapse td-sidebar-nav" id="td-section-nav">
    <ul class="td-sidebar-nav__section pe-md-3 ul-0">
          <li> .... </li>          

If you're using other Hugo themes other than Docsy, you can use the same trick to save and restore the scroll position.

Note
I found the above code from a demo website of Hugo Book theme.
Last modified: 2024-07-09