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. Switch to html5 in eg, ikiwiki 4; users have to deal with
>    any custom markup on their pages/templates that breaks then.
> 3. Have both a html5 and a xhtml mode, allow user to select.
>
> The third 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.
> 
> Some of your changes are obvious, like using the new `time` and
> and `article` elements. Others less so, and I'm particularly
> puzzled by these:
> 
> * Removing the value="Submit" from the button on the 
>   commentmoderation form.
> * Removing feedlink.tmpl. What?!
> * Using a `h2` for the header of inlinepage.tmpl and page.tmpl, rather
>   than the styled span. Ikiwiki has
>   [[a_reason|todo/Option_to_make_title_an_h1?]] for not
>   using real `hN` for the header atop a page and here.
>   AFAICS, html5 does not invalidate that.
> * Removing Editurl from inlinepage.tmpl actions. I assume 
>   this is your own preference, needs to be removed from branch
>   before I can use it.
> * Removing the pageheader, content, and footer divs
>   which are all used by style.css.
>   Perhaps, the style sheet needs to be updated to use
>   the new elements, like the `footer` and `header`.
> * Removal of the favicon from page.tmpl. Surely html5 supports?
> * Removal of BASEURL from page.tmpl, apparently a mistake.
> * Removal of the `/` between wiki title and page title.
>   Personal preference.
> * Removal of `comments` div, which is there to be styled.
> * Why use a `p` rather than the `div` for `addcomments`?
> * Moving the action bar to the bottom of the page.
>   Personal preference.
> * Clearly searchquery.tmpl has no business using bad old `center`
>   tag, but something should still be done to replace it.
> 
> (BTW, it would be helpful if you could re-merge master into your branch
> as it is a bit diverged now.) 
> 
> Other ideas:
> 
> * Add pubdate attribute to time elements as appropriate.
> * Use aside for the sidebar? Or for the [[templates/note]] template?
> * Use nav for the actionbar
> * Use placeholder in the search box. Allows closing
>   [[this_todo|Add_label_to_search_form_input_field]]
> --[[Joey]] 

# htmlscrubber.pm needs to not scrub new HTML5 elements

* [new elements](http://www.w3.org/TR/html5-diff/#new-elements)

> Most of these can be supported trivially, since they are just semantic
> markup. Make a list of these, and their attributes (and which attributes
> can contain urls or other javascript injection mechanisms), and I can add
> them. (Added several now.) Others, like `embed` are *scary*. --[[Joey]]

> 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.

## 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]]