-Some elements of [HTML5](http://www.whatwg.org/specs/web-apps/current-work/multipage/) can be safely supported by ikiwiki. There are [several differences between HTML4 and HTML5](http://www.w3.org/TR/html5-diff/). Unsupported new elements _should degrade gracefully_.
-
-> In the `origin/html` branch, there is an old work in progress to make
-> ikiwiki use html 4 instead of xhtml. If that could be brought forward and
-> finished then the plan has been to switch ikiwiki over to doing html 4.
-> I don't think it makes sense to try to make it support both xhtml and
-> html, it would complicate the code for no benefit.
->
-> I think that is the best route toward supporting html 5 as well. Get
-> ikiwiki doing html 4 first and the changes needed to get to 5 from there
-> should be small. Probably just changing some doctypes and a few other
-> small changes which could be kept in a branch, or even shipped in ikiwiki
-> mainline as an alternate set of templates. Some of the changes, like
-> supporting new html 5 tags in the htmlscrubber, can be done in mainline.
-> (Like was already done for the html 5 video and audio tags.)
+Some elements of
+[HTML5](http://www.whatwg.org/specs/web-apps/current-work/multipage/) can be
+safely supported by ikiwiki. There are [several differences between HTML4 and
+HTML5](http://www.w3.org/TR/html5-diff/).
+
+[[!template id=gitbranch branch=hendry/html5 author="[[Kai_Hendry|hendry]]"]]
+
+* [HTML5 branch](http://git.webconverger.org/?p=ikiwiki;h=refs/heads/html5)
+* [ikiwiki instance with HTML5 templates](http://natalian.org)
+* [HTML5 outliner tool](http://gsnedders.html5.org/outliner/) -- to check you have the structure of your markup correct
+
+> 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]]
+
+# htmlscrubber.pm needs to not scrub new HTML5 elements
+
+* [new elements](http://www.w3.org/TR/html5-diff/#new-elements)
+
+> Many added now.
>
-> This approach seems much more maintainable going foward than rolling a
-> html 5 branch immediatly and trying to keep that continually up-to-date
-> with mainline ikiwiki that is still using xhtml. --[[Joey]]
+> 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
+
+[validator.nu](http://validator.nu/) 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](http://wiki.whatwg.org/wiki/IDE), though Debian packages cannot be built
+with a network dependency.
+
+In the future, hopefully ikiwiki can test for valid HTML5 using [Relax NG
+schema](http://syntax.whattf.org/) using a Debian package tool
+[rnv](http://packages.qa.debian.org/r/rnv.html).
+
+> Validation in the test suite is nice, but I am willing to lose those
+> tests for a while. --[[Joey]]
+
+# HTML5 migration issues
+
+# [article](http://www.whatwg.org/specs/web-apps/current-work/multipage/semantics.html#the-article-element) 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
-However as an [early adopter](http://en.wikipedia.org/wiki/Early_adopter) I would like to start using HTML5 as much as possible. The more pragmatic solution would be to use elements supported by the browsers of your readership I guess. I'm following other early adopters like [Anne](http://annevankesteren.nl/) for clues on how to proceed.
+The [time element](http://www.whatwg.org/specs/web-apps/current-work/multipage/text-level-semantics.html#the-time-element) ideally needs the datatime= attribute set by a template variable with what [HTML5 defines as a valid datetime string](http://www.whatwg.org/specs/web-apps/current-work/multipage/infrastructure.html#valid-global-date-and-time-string).
-* [Initial patch](http://git.webconverger.org/?p=ikiwiki;a=commit;h=2e2bb3f74f5000b1269142d6f9bdf1bcb4075ca4)
+As a workaround:
-> I can't figure out how to pull from this repository.
->> Sorry! I have fixed the cloneurl file to read `git clone git://webconverger.org/git/ikiwiki`
+ au:~% grep timeformat natalian.setup
+ timeformat => '%Y-%m-%d',
-I'm unsure how to turn off the test validation by the very old [wdg-html-validator](http://packages.qa.debian.org/w/wdg-html-validator.html). So I have been unable to test my initial patches as I can't build ikiwiki. I would like to know how to edit the rules/Makefile to temporarily disable this.
+> Also, the [[plugins/relativedate]] plugin needs to be updated to
+> support relatatizing the contents of time elements. --[[Joey]]
-> Don't run ¨make test" ... --[[Joey]]
->> I don't quite grok debhelper7 [rules](http://git.ikiwiki.info/?p=ikiwiki;a=blob;f=debian/rules).
+> Done and done; in html5 mode it uses the time tag, and even
+> adds pubdate when displaying ctimes. --[[Joey]]
->>> Well, ok :-) `rm t/html.t` or, add an empty `override_dh_auto_test` rule.
->>> --[[Joey]]
+## tidy plugin
-[validator.nu](http://validator.nu/) incidentally is **the** 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](http://wiki.whatwg.org/wiki/IDE), though Debian packages cannot be built with a network dependency.
+Will reformat html5 to html4.
-# Notes
+----
-* the [time element](http://www.whatwg.org/specs/web-apps/current-work/multipage/text-level-semantics.html#the-time-element) ideally needs the datatime= attribute set with iso8601 time
-* I suspect the migration to the new semantic elements of HTML5 like article, header & footer to take some time, due to browser support. Though they sure make the template code look much nicer.
-* `<br>` and too many `<div>`s usually indicates poor semantics.
- > YMMV, but I tend to find that kind of concern counterproductive.
- > --[[Joey]]
-* Many of the header `<span>`s should be proper [header elements](http://www.whatwg.org/specs/web-apps/current-work/multipage/semantics.html#the-h1,-h2,-h3,-h4,-h5,-and-h6-elements)
- > See [[todo/Option_to_make_title_an_h1__63__]] for why not. --[[Joey]]
+Ok, I consider this [[done]], at least as a first pass. Html5 mode
+is experimental, but complete enough. --[[Joey]]