Some elements of HTML5 can be safely supported by ikiwiki. There are several differences between HTML4 and HTML5.

Available in a git repository branch.
Branch: hendry/html5
Author: Kai Hendry

Kai, thanks enormously for working on this. I switched a page to the html5 doctype today, and was rather pleasently suprised that it validated, except for the new Cache-Control meta tag. Now I see you're well ahead of me. --Joey

So, how should ikiwiki support html5? There are basically 3 approaches:

  1. Allow users to add html5 tags to their existing xhtml pages. What has been done so far, can be extended. Basically works in browsers, if you don't care about standards. A good prerequisite for anything else, anyway.
  2. Have both a html5 and a xhtml mode, allow user to select.
  3. Switch to html5 in eg, ikiwiki 4; users have to deal with any custom markup on their pages/templates that breaks then.

The second option seems fairly tractable from what I see here and in your branch. You made only relatively minor changes to 10 templates. It would probably not be too dreadful to put them in ifdefs. I've made a small start at doing that.

I've made ikiwiki use the time element and all the new semantic elements in html5 mode.

Other ideas:

  • Use details tag instead of the javascript in the toggle plugin. (Need to wait on browser support probably.)
  • Use figure and figcaption for captions in img. However, I have not managed to style it to look as good as the current table+caption approach.

--Joey needs to not scrub new HTML5 elements

Many added now.

Things I left out, too hard to understand today: Attributes contenteditable, data-*, draggable, role, aria-*. Tags command, keygen, output.

Clearly unsafe: embed.

Apparently cannot be used w/o javascript: menu.

I have not added the new ping attribute, because parsing a space-separeated list of urls to avoid javascript injection is annoying, and the attribute seems generally dubious. --Joey

HTML5 Validation and t/html.t is the authorative HTML5 validator, however it is almost impossible to sanely introduce as a build dependency because of its insane Java requirements. :( I test locally via cURL, though Debian packages cannot be built with a network dependency.

In the future, hopefully ikiwiki can test for valid HTML5 using Relax NG schema using a Debian package tool rnv.

Validation in the test suite is nice, but I am willing to lose those tests for a while. --Joey

HTML5 migration issues

article element

This element is poorly supported by browsers. As a workaround, style.css needs:

article {
    display: block;

Internet Explorer will display it as a block, though you can't seem to be able to further control the style.

done (needed for header too) --Joey

Time element

The time element ideally needs the datatime= attribute set by a template variable with what HTML5 defines as a valid datetime string.

As a workaround:

au:~% grep timeformat natalian.setup
timeformat => '%Y-%m-%d',

Also, the relativedate plugin needs to be updated to support relatatizing the contents of time elements. --Joey

Done and done; in html5 mode it uses the time tag, and even adds pubdate when displaying ctimes. --Joey

tidy plugin

Will reformat html5 to html4.

Ok, I consider this done, at least as a first pass. Html5 mode is experimental, but complete enough. --Joey