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This day’s portion

Two things I learned by validating my HTML again

I periodically validate my HTML, because validated HTML should be more robust and accessible than unvalidated. It’s also an indicator of competence. (Note to self: I should include validation in my build process.)

This time round I discovered some new errors, which proved easy to fix. My HTML still doesn’t quite validate (so therefore I’m not quite competent, I suppose 😊) because I inline my CSS, and that CSS contains a parse error I can’t figure out. I also knowlingly add an invalid attribute to comment forms so inputs behave properly on Apple phones. View the source and you’ll see the HTML is commented to reflect this.

Elements should only contain one instance of an attribute

Take this (invalid) code:


Note the two rel attributes – one tells the browser that the resource at,400i,700&display=swap is a stylesheet while the other asks the browser to preload it.

Having two rels is invalid, but having two rel values is fine (and often necessary). This makes sense because how do we determine which is the right rel, and if one has been added in error? Instead, use one rel and add two space-separated values.

rel="preload stylesheet"

Oh yeah, I’d also been sloppy editing my comments include and generated headings with two class attributes. Tsk.

img elements must have an alt attribute even if they’re hidden from assistive technology

Of course I know images should contain descriptive text for screenreaders. However, we can hide decorative images from screenreaders altogether by setting the aria-hidden boolean attribute to true:

<img src='/images/guards.jpg' aria-hidden="true" height="72" width="72">

This is invalid because it doesn’t contain an alt attribute. I’m not sure the logic here is right; after all, I’ve said the image should be ignored, so why does it need a description? Or I might not be understanding how to implement this accessibly. Either way, this is valid:

<img src='/images/guards.jpg' alt="" aria-hidden="true" height="72" width="72">

So there you go. This time round, validation reminded me how to add attributes properly and perhaps keep images accessible.