Re-factor templates and theme functions to use new HTML5 elements

Overview

HTML5 brings a number of new elements to enhance the semantics of our web pages. The table below lists these new elements along with links to the spec and relevant articles on each.

New HTML5 Elements

Element	Spec	Articles
article	WHATWG | W3C	HTML5 Doctor, Dive into HTML5
aside	WHATWG | W3C	HTML5 Doctor
audio	WHATWG | W3C	HTML5 Doctor
bdi	WHATWG | W3C	HTML5 Doctor
canvas	WHATWG | W3C	HTML5 Doctor
command	WHATWG | W3C
datalist	WHATWG | W3C
details	WHATWG | W3C
embed	WHATWG | W3C
figcaption	WHATWG | W3C	HTML5 Doctor
figure	WHATWG | W3C	HTML5 Doctor
footer	WHATWG | W3C	HTML5 Doctor, Dive into HTML5
header	WHATWG | W3C	HTML5 Doctor, Dive into HTML5
hgroup	WHATWG | W3C	HTML5 Doctor
keygen	WHATWG | W3C
mark	WHATWG | W3C	HTML5 Doctor
meter	WHATWG | W3C
menu	WHATWG | W3C
nav	WHATWG | W3C	HTML5 Doctor, Dive into HTML5
output	WHATWG | W3C
progress	WHATWG | W3C
section	WHATWG | W3C	HTML5 Doctor
source	WHATWG | W3C
summary	WHATWG | W3C
time	WHATWG | W3C	HTML5 Doctor, Dive into HTML5
track	WHATWG | W3C	HTML5 Doctor
video	WHATWG | W3C	HTML5 Doctor
wbr	WHATWG | W3C

Related Issues/Discussions

#1077510: Convert core templates and theme functions to HTML5 - Meta Issue
#1085590: Update jQuery UI to the latest in the git repository

Templates

Template	Issue(s)
aggregator-feed-source.tpl.php	#1189804: Convert aggregator-feed-source.tpl.php to HTML5
aggregator-item.tpl.php	#1189806: Convert aggregator-item.tpl.php to HTML5
aggregator-summary-item.tpl.php	#1221710: Convert aggregator-summary-item.tpl.php to HTML5
aggregator-summary-items.tpl.php	#1189810: Convert aggregator-summary-items.tpl.php to HTML5
aggregator-wrapper.tpl.php	#1221712: Convert aggregator-wrapper.tpl.php to HTML5
block.tpl.php	#1077610: Convert block.tpl.php to HTML5
block-admin-display-form.tpl.php	#1221718: Refactor block-admin-display-form.tpl.php
book-all-books-block.tpl.php	#1189832: Convert book-all-books-block.tpl.php to HTML5
book-export-html.tpl.php	#1189834: Convert book-export-html.tpl.php to HTML5
book-navigation.tpl.php	#1189828: Convert book-navigation.tpl.php to HTML5
book-node-export-html.tpl.php	#1221724: Convert book-node-export-html.tpl.php to HTML5
comment.tpl.php	#1189816: Convert comment.tpl.php to HTML5
comment-wrapper.tpl.php	#1229434: Convert comment-wrapper.tpl.php to HTML5
forum-submitted.tpl.php	#1189850: Convert forum-submitted.tpl.php to HTML5
html.tpl.php	#1077566: Convert html.tpl.php to HTML5
maintenance-page.tpl.php	#1189822: Convert maintenance-page.tpl.php to HTML5
node.tpl.php	#1077602: Convert node.tpl.php to HTML5
poll-bar--block.tpl.php	#1229440: Convert poll-bar--block.tpl.php to HTML5
poll-bar.tpl.php	#1229442: Convert poll tpls and markup to HTML5
poll-results--block.tpl.php	#1190172: Convert poll-results--block.tpl.php to HTML5
poll-results.tpl.php	#1229444: Convert poll-results.tpl.php to HTML5
poll-vote.tpl.php	#1190176: Convert poll-vote.tpl.php to HTML5
profile-block.tpl.php	#1229450: Convert profile-block.tpl.php to HTML5
profile-listing.tpl.php	#1190202: Convert profile-listing.tpl.php to HTML5
page.tpl.php	#1077578: Convert page.tpl.php to HTML5
taxonomy-term.tpl.php	#1190206: Convert taxonomy-term.tpl.php to HTML5
toolbar.tpl.php	#1190210: Convert toolbar.tpl.php to HTML5
user-profile.tpl.php	#1190214: Convert user-profile.tpl.php to HTML5
user-profile-category.tpl.php	#1190218: Convert user-profile-category.tpl.php to HTML5

Theme Functions

Theme Function	Issue(s)
theme_field()	#1189842: Convert theme_field() to HTML5
theme_datetime()	#1183250: Add a theme_datetime() function to consistently theme dates and datetimes
theme_book_title_link()	#1222248: Remove theme_book_title_link()
theme_task_list()	#1222254: theme_task_list() should be replaced with theme_item_list() in all instances
theme_filter_tips_more_info()	#1222260: theme_filter_tips_more_info() should be replaced with the l() function
drupal_placeholder()	#1447678: Fix strings with broken semantics caused by using %variable placeholder incorrectly

Upgrade Theme Functions to support the render system

For D8, all theme functions should support the render system. This provides support for HTML content to be passed to any theme function with the expectation that the HTML content will be render as DOM and not text.

We will start with theme_datetime and use this as the model for existing theme functions that do not support the render system (to be listed) and new theme functions (see above).