What is the best syntax to use for declarative markup in HTML5?

Declarative Component Mapping Syntax Options.textile

Declarative Component Mapping Syntax Options

Language / Prior Art	‘Valid’ HTML	HTML Mapping	Example	Example with Args
‘Valid’	CSS Selectable	CSS Mapping	CSS Select	CSS Selector w Args
JavaScript MooTools		Multiple instance Separate Args	new Foo(element); new Bar(element)	new Foo(element, {a:"a", bB:"b B", c:{c:1}}); new Bar(element, {d:"d"})
—	—	—	—	—
HTML attr Dojo <1.6	NO	1 Element per instance	<div nsType=foo>	<div nsType=foo a=a bB="b B" c.c=1>
	CSS: A	Single + Args	[nsType]	[nsType=Foo][a=a][bB~=b][bB~=B][c.c=1]
data-* Dojo 1.6+	YES	1 Element per instance	<div data-ns="Foo">	<div data-ns="Foo" data-ns-a="a" data-ns-b-b="b B" data-ns-c.c="1">
	CSS: A	Single + Args	[data-ns-type]	[data-ns-type=Foo][data-ns-a=a][data-ns-bB~=b][data-ns-bB~=B][data-ns-c.c=1]
class & attr Apple iAd	NO	Multiple instances Combined Args	<div class="ad-foo ad-bar"></div>	<div class="ad-foo ad-bar" ad-title="MyBarButton"></div>
	CSS: A+	Multi + Args	.ad-foo, .ad-bar	.ad-foo[ad-title], .ad-bar[ad-title]
data-* Hue Behavior	YES	Multiple instances Combined Args	<div data-filters="ns.foo, ns.bar">	<div data-filters="ns.foo, ns.bar" data-a="a" data-b-b="b B" data-c='{"c":1}' data-d="d">
	CSS: D	All + Args	[data-filters]	[data-filters][data-a=a][data-bB~=b][data-bB~=B]
data-* & CSS	YES	Multiple instances Separate Args	<div data-ns data-ns.foo data-ns.bar>	<div data-ns data-ns.foo="a:a; b-b:b B; c{c:1}" data-ns.bar="d:d">
	CSS: B	Multi	[data-ns]	[data-ns.foo], [data-ns.bar]
attr & CSS	NO	Multiple instances Separate Args	<div ns foo bar>	<div ns foo="a:a; b-b:b B; c{c:1}" bar="d:d">
	CSS: B	Multi	[ns]	[ns][foo], [ns][bar]
data-*	YES	Multiple instances Separate Args	<div data-ns="Foo Bar Baz">	<div data-ns="Foo Bar Baz" value=HTML data-foo.value=FOO data-bar.value=BAR>
	CSS: A++	Multi + Multi Args	[data-ns]	[data-ns~=Foo][value=Frog]:not([data-foo.value]), [data-ns~=Foo][data-foo.value=Frog]
HTML attr	NO	Multiple instances Separate Args	<div ns="Foo Bar Baz">	<div ns="Foo Bar Baz" value=HTML foo.value=FOO bar.value=BAR>
	CSS: A++	Multi + Multi Args	[ns]	[ns~=Foo][value=Frog]:not([foo.value]), [ns~=Foo][foo.value=Frog]
data-*	YES	Multiple instances Separate Args	<div data-ns="Foo, Bar, Baz">	<div data-ns="Foo:value(FOO), Bar:value(BAR), Baz:value(HTML)" value=HTML>
	CSS: D-	All	[data-ns]	—
data-*	YES	Multiple instances Separate Args	<div data-ns="Foo, Bar, Baz">	<div data-ns="Foo[value=FOO], Bar[value=BAR], Baz[value=HTML]" value=HTML>
	CSS: D-	All	[data-ns]	—

xample.datagrid.1-1_data-attr.html

<meta data-is=DataStore.JSON name=jsonStore content=dataItems.json>

<meta data-is=Model.Forest name=continentModel
	content=jsonStore data-query=type:continent
	data-root-id=continentRoot data-root-label=Continents data-children-attrs=children
>

<table data-is=DataGrid.Tree id=grid data-model=continentModel>
	<thead>
		<tr>
			<th data-field=name style=width:auto>Name
			<th data-field=population style=width:auto>Population
			<th data-field=timezone style=width:auto>Timezone
	</thead>
</table>

xample.datagrid.dojo15.html

<span dojoType="dojo.data.ItemFileWriteStore"
	jsId="jsonStore" data="dataItems"></span>

<div dojoType="dijit.tree.ForestStoreModel" jsId="continentModel"
	store="jsonStore" query="{type:'continent'}"
	rootId="continentRoot" rootLabel="Continents" childrenAttrs="children"></div>

<table jsid="grid" dojoType="dojox.grid.TreeGrid" class="grid" treeModel="continentModel">
	<thead>
		<tr>
			<th field="name" width="auto">Name</th>
			<th field="population" width="auto">Population</th>
			<th field="timezone" width="auto">Timezone</th>
		</tr>
	</thead>
</table>


<a href="http://archive.dojotoolkit.org/nightly/dojotoolkit/dojox/grid/tests/test_treegrid_model.html" title="dojox.grid.TreeGrid Model-based test">Example from Dojo Toolkit dojox.grid.TreeGrid Model-based test</a>

@digitarald Mapping of alias to specific JS namespace should happen in JS, not HTML. e.g. SubtleBehavior.defineAlias({zebra: My.NameSpace.Of.Doom.Zembra, foo:Foo, bar:MySuperBar})

See https://gist.github.com/765730 for the thread about Behavior Sheets.