HTML, avoid displaying a broken image if the image is not found

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

Being sure 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"  

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

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

Another thing you could do is display a fallback image, if you need, 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.

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