how many elements in HTML5 are containers for scripted APIs?

http://diveintohtml5.ep.io/extensibility.html:

There a开发者_JAVA百科re over 100 elements in HTML5. Some are purely semantic, others are just containers for scripted APIs.

Am i right to say that there is only one element acting as a container for scripted APIs which is the canvas? because that sentence seems to suggest that there are multiples.. am i missing some elements other than the canvas here?

That line is referencing the difference between new semantic tags like nav, article, footer, etc. which provide no functionality, and new API-providing host objects that do provide new functionality.

HTML5 introduces a set of new semantic tags so you don't need to use div for everything, but they provide zero new functionality. HTML5 also introduces some other tags such as canvas, video, and audio which provide new functionality for playing media, manipulating graphics, etc. There's also a number of new APIs that introduce new functionality, but aren't part of html5, but are widely lumped in with html5 anyway.

Regardless, the reference is vs. the new semantic (but functionally useless) html tags, and the functional apis that are referenced via new tags.

If you want an actual enumeration of what's part of html5 that provides new host objects...I'll have to get back to you. The html5 specification and dependent W3C specifications comprise multiple thousands of pages.

I guess it depends on what you mean by scripted APIs, but audio, video, web-workers, geolocation, & local storage spring to mind when I read your question.

I think the authors differentiating between new page layout elements (header, aside, content) & css3 as opposed to new technologies that are entering the browser space (or maturing) as html5 is released as a markup spec.