[DAS2] hrefs and xml:base

Ed Erwin ed_erwin at affymetrix.com
Fri May 6 17:16:03 UTC 2005

The document you cite as defining xml:base leaves me with an unanswered 
question.  It says that this is inspired by the html <base> tag, but 
doesn't say whether it works in the same complex way that html <base> works.

Namely, with this base tag:
<BASE href="http://www.aviary.com/products/intro.html">

This href:

resolves to:

In other words, it doesn't simply do a String concatenation of the base 
and the href, but rather has to throw away the "intro.html" part and 
interpret the meaning of ".."

This example comes from

Is there some more complete specification of xml:base that states 
whether these complicated things are allowed?

Helt,Gregg wrote:
> If we want to fully adopt the xml:base standard (which I think we do),
> then my interpretation is that xml:base is lexically scoped and within
> its scope allows any attribute that requires a URI to be potentially
> specified as a relative URI (relative to the xml:base) instead of an
> absolute URI.  
> So I would say "href", "doc_href", "id", and a number of other
> attributes should obey the xml:base directive(s).  Note that this
> doesn't preclude using an absolute URI for these values, it just also
> allows using a relative URI.
> Here's a nice concise summary of xml:base :
> http://www.brics.dk/~amoeller/XML/common/xbase.html

More information about the DAS2 mailing list