haliphax

A while back, I scratched my own itch for automated webpage scrolling (e.g. for AWS logs) by creating a bookmarklet that would slam the scrollbar to the bottom of the document every second. It was a ham-fisted approach, but it worked.

I have recently come to find, however, that this does not work on many so-called "modern" web applications where the UI has been sliced into multiple divisions, each with their own view boundaries and scrolling-related properties. To work around this, I have revamped the old bookmarklet so that you give it a hint by scrolling the element you want to target. So far, it's doing exactly what I need.

Noteworthy elements include the use of the addEventListener options capture and once, which are responsible for capturing the scroll event (which does not bubble) and firing the hook to call setInterval for the scrolling work only once without the need for any removeEventListener shenanigans.

Grab the bookmarklet for yourself by dragging the link below onto your bookmarks bar:

Tail

Here is the source code, altered for formatting and clarity:

(() => {
  if (window.hx_tail) {
    clearInterval(window.hx_tail);
    delete window.hx_tail;
    alert("Disabled");
  } else {
    alert("Scroll target element");
    document.addEventListener(
      "scroll",
      (e) => {
        window.hx_tail = setInterval(() => {
          e.target.scrollTop = e.target.scrollHeight;
        }, 1000);
      },
      {
        capture: true,
        once: true,
      },
    );
  }
})();