Saxon » SaxonJS

I believe the places we use the URI library are:

(a) to implement the resolve-uri() function (CoreFn.js)

(b) in DOMUtils, (baseURI function) to test whether a URI is absolute (and then resolve it if not)

(c) when initiating the transformation, to resolve the supplied stylesheet URI against the URI of the HTML page

When we're in the browser, I think it makes sense to try the resolve-uri() method given here:

http://stackoverflow.com/questions/470832/getting-an-absolute-url-from-a-relative-one-ie6-issue

specifically

function resolve(url, base_url) {
  var doc      = document
    , old_base = doc.getElementsByTagName('base')[0]
    , old_href = old_base && old_base.href
    , doc_head = doc.head || doc.getElementsByTagName('head')[0]
    , our_base = old_base || doc_head.appendChild(doc.createElement('base'))
    , resolver = doc.createElement('a')
    , resolved_url
    ;
  our_base.href = base_url || '';
  resolver.href = url;
  resolved_url  = resolver.href; // browser magic at work here

  if (old_base) old_base.href = old_href;
  else doc_head.removeChild(our_base);
  return resolved_url;
}

This essentially adds a <base> element to the header of the HTML page, and creates an <a> element containing the relative URI, and then piggy-backs on the fact that the browser knows how to resolve relative URIs in <a> elements.

We should give this a try. We would still need to use the URI.js library in non-browser environments.