ikiwiki/doc/bugs/html5_support.mdwn

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.
>
> 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

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).

As a workaround:

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

> Also, the [[plugins/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]]