Whether you’re a fan of scripted ebooks or not, EPUB 3 has opened the door to their creation, so we’ll now take a look at some of the potential accessibility pitfalls and how they can be avoided.
One of the key new terms you’ll hear in relation to the use of scripting in EPUB 3 is progressive enhancement. The concept of progressive enhancement is not original to EPUB, however, nor is it limited to scripting. I’ve actually been making a case for many of its other core tenets throughout this guide, such as separation of content and style, content conveying meaning, etc. Applied in this context, however, it means that scripting must only enhance your core content.
And that’s why scripting access to content is forbidden in EPUB 3. If you try to circumvent the specification requirement and treat progressive enhancement as just an “accessibility thing,” you’re underestimating the readership that are going to rely on your content rendering properly without scripting. Picture buying a book that has pages glued together and you’ll get an idea of how excited your readers will be that you thought no ...