[whatwg] Partial HTML5 documents

[Thomas Broyer]

On Thu, Sep 9, 2010 at 6:37 PM, Rostislav Hristov wrote:
> I'm actually looking into manually editing these in an authoring
> environment and this is why I want them to be valid.
>
> The parsing section looks fine but it doesn't help in this case.

Yes, sorry, I was thinking in terms of "parse errors".

I think there's no answer to your question, as validity of a DOM
subtree depends on where you attach it: for instance,
"<span>foo</span>" would be valid if put inside a <p> (in an already
valid document), but not if put inside, say, a <tr>. And it's a simple
example.
You'd have to provide a "context" for validating your HTML fragment,
just like when parsing the fragment. I think the best you can do is to
parse the fragment using the spec'd algorithm (if you're not already
dealing with a DOM tree) and then attach the result to a simple HTML
document (containing a <title> and providing the "context" you want to
validate the fragment in); but even that would not cover all cases and
your fragment could very well turn into something invalid when put in
some documents (duplicate IDs, <footer> inside a <footer>, sectionning
content inside an <address>, something not an hN inside an <hgroup>,
etc.)

-- 
Thomas Broyer
/tɔ.ma.bʁwa.je/