This is a follow-up post to JavaScript and the end of progressive enhancement - you may want to read that first if you haven’t already. The comments are worth a read, as well as the Reddit thread.

The app/doc divide

What I didn’t make clear in my original post (because I wasn’t fully clear about it at the time) is the distinction between document-based web sites, and web applications. Documents are made to be read, whereas apps are made to be interacted with. James Pearce wrote a great description in the comments:

Actually what we’re maybe observing here is a clash of civilisations: the documentistas vs the applicationistas; web-as-a-medium vs web-as-a-technology-stack; designers vs programmers. It’s no wonder that progressive enhancement is a powerful tenet for the former of each pair to rally around… but not necessarily the most architecturally important consideration of the latter.

[James has since written a great, and highly relevant, post on the subject of URLs in JS apps.]

It goes without saying that apps and documents are two completely different things (even though there is a huge amount of overlap between the two). Trying to treat web design/development as a single discipline is a mistake. Anything that is primarily meant for reading, such as a newspaper website or a blog, exists as a collection of documents. I should be able to link to another blogger’s blog post and expect that in a week or a year that content will still be available at that address. I shouldn’t need to have JavaScript enabled in order to visit that address.

Web apps aren’t the same thing. A web app is an application that happens to use web technologies. Most web apps could be desktop apps – what makes a web app a web app is that it is accessed using a browser. No-one expects to be able to hyperlink to a particular view in Microsoft Excel – what would that even mean? In the same way, I can’t share a link to a particular email in Gmail. Web apps don’t always exist in the same web as everything else – many apps are islands.

Historically, web apps have been built in the document-based paradigm, using links to move to different parts of the app and forms to submit data for processing. The only reason they were made like this was because this was all the technology allowed. Now that technology has advanced, first with Ajax and now with HTML5, we aren’t tied to this old practice.

Amy Hoy summed it up nicely:

The problem is that because everyone building stuff online is using the same technologies, there can be a tendency to think that there is one true way of using those technologies, independent of what they’re being used for. This is clearly false.

The end of progressive enhancement?

Progressive enhancement is still the way to make document-based sites on the web – there’s no denying that. But with applications the advantages are less clear. If we can accept the fact that the document-based paradigm isn’t the best way to make web apps, then we should also accept the fact that progressive enhancement doesn’t apply to apps.