Vanilla JavaScript: Add Class to Image Links

It seems that for every new web design, I need to add a specific CSS class to linked images. So I can distinguish between regular text links and image links. And then apply styles as desired for each. I’ve tried all sorts of CSS and JavaScript/jQuery tricks over the years, but so far this one is the best..

Of course, “best” is relative. For me, this snippet is great because it’s simple, lightweight, and written in vanilla JavaScript. So there are no dependencies.

Magic Bullet

Here is the magic code, strictly plug-&-play:

window.onload = function() {
	imageLinks();
}

function imageLinks() {
	var anchors = document.querySelectorAll('a');
	Array.prototype.forEach.call(anchors, function(a) {
		var img = a.querySelector('img');
		if (img !== null) {
			a.classList.add('img-link');
		}
	});
}

This snippet does one thing: adds a class named img-link to all links <a> that contain an image <img> element. Simply add the code and done.

After adding this code, any/all image links will include a class named img-link. Here is an example of the HTML output after applying the above snippet:

<a href="/path/to/somewhere/" class="img-link">
	<img src="/path/to/image.png" alt="">
</a>

So now we can add styles specifically to links that contain an image. For example:

.img-link { border: 1px solid gold; }
.img-link img { border: none; }

Let me know if you can find any way to improve this “magic bullet” vanilla JavaScript technique. Or maybe now it can be done with simple CSS..?

About the Author

Jeff Starr = Fullstack Developer. Book Author. Teacher. Human Being.