Error HTM_061: not valid custom attribute

[Daniele Giampà]

Hello

I created an EPUB3 ebook enriched with AR images and animations titled "Mingled Memories":
https://www.edgedpub.com/sample_work_1.php

I was very surprised to see that there were 243 errors. (attached)
However, it's always the same error code HTM_061.

I am not sure what to do. I am afraid that if I change the code in the XHTML file, I will have to change the JS file too.

Is anybody familiar with this issue?

Many thanks.

Daniele

[KevinH]

Yes rule _061 just restates the specification rules regarding the naming of custom data- attributes in html5:

Custom data attributes must be named with the prefix 'data-', followed by at least one character. The attribute name should not contain any uppercase letters, and must be at least one character long after the 'data-' prefix. The attribute name should not contain any semicolons.

And in each case your data- attribute uses mixed upper and lower case names which violates the rules.

The javascript you are using probably relies on those mixed case names.

So use Find and Replace to generate a list of every attribute that begins with "data-" and uniquely sort them. Then search through your javascript code replacing every occurrence with its lowercase equivalent. Then for the xhtml, do the same. It could just be the start and end state ones. So if you are really lucky it might turnout to be a really short list of data- attribute names that need to be fixed.

If this is a third party javascript library, I would look for a more spec compliant version or I would file a bug report against it as it does not meet spec.

[Daniele Giampà]

Thank you very much Kevin!