[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

Re: Minimal set of rules for making HTML well-formed?

• From: "Liam R. E. Quin" <liam@fromoldbooks.org>
• To: "Costello, Roger L." <costello@mitre.org>, "xml-dev@l..." <xml-dev@l...>
• Date: Fri, 11 Oct 2019 13:33:00 -0400

On Fri, 2019-10-11 at 16:21 +0000, Costello, Roger L. wrote:
> 
> I've decided to implement my own tool to convert HTML to XHTML.

You should probably investigate HTML Tidy first.

>   1.  Ensure that attribute values are delimited with either double
> or single quotes.
>   2.  Ensure that every start tag has a matching end tag.
>   3.  Ensure that elements are properly nested.
>   4.  Ensure that the XML reserved characters ( <, >, &, ', ") are
> escaped when used in data.
> 
> Am I missing anything? If my tool does those 4 things am I guaranteed
> that the resulting document will be well-formed?  /Roger

Yes, you also have to process the internal subset, which has different
rules, and you have to handle encoding errors. You also need to ensure
there's a single top-level element (not required in HTML partly because
of OMITTAG in SGML but mostly because early Web browsers treated tags
as "commands").

If your goal is just to run XSLT on HTML, both Saxon (with TagSoup) and
xsltproc (XSLT 1) can do this already.


-- 
Liam Quin, https://www.delightfulcomputing.com/

Upcoming course: XSLT 3 for XSLT People, November 18th-20th

• References:
  • Minimal set of rules for making HTML well-formed?
    • From: "Costello, Roger L." <costello@mitre.org>