While working on a website, I was loading an image dynamically based on the current page URL.

Since I knew I’d eventually forget to create an image in the future, I looked into avoiding the usual “broken image” that says “this website is abandoned”.

The technique I used is this:

<img src="/{{$bookname}}.png" onerror="this.remove()" />

TIP: this inside an inline event handler in HTML refers to “this element”

Sure, the optimal way is to make sure images are always working. But that’s not always realistic. This is a workaround that uses platform features because I know I might not pay attention to that as a solo developer and could have a broken image visible for weeks before I realize.

Another thing you could do is display a fallback image, if you need one, in this way:

<img
  src="/{{$bookname}}.png"
  onerror="this.onerror=null; this.src='fallback.png'"
/>

this.onerror=null here is needed so there’s no “infinite loop” if the fallback image is not found.

Lessons in this unit:

0:	Introduction
1:	Preserving white space and line breaks in a string in HTML
2:	▶︎ HTML, avoid displaying a broken image if the image is not found
3:	The HTML figure tag
4:	Change image source in dark mode
5:	Accept only images in file input
6:	HTML comments
7:	Some useful tricks available in HTML5
8:	How to make an hr invisible
9:	Conditionally set an HTML attribute
10:	An HTML element id is a global variable