32842 - FEATURE: Implement XML Base

Status: VERIFIED FIXED

(Core :: XML, defect, P3)

Description

[Heikki Toivonen (remove -bugzilla when emailing directly)]

XML Base is a W3C WD (in Final Call):

http://www.w3.org/TR/xmlbase

XML Base is similar to the base attribute in HTML. It is also a prerequisite for
XLink.

Comment 1

[Heikki Toivonen (remove -bugzilla when emailing directly)]

Attachment: WIP: Logic but no URI escaping for special characters

Comment 2

[Heikki Toivonen (remove -bugzilla when emailing directly)]

The above patch should have the XML Base logic implemented, as far as I can 
tell. What remains to be done is to convert the Unicode string to ??? encoding 
that fits into char*, and then doing URL-escaping (i.e. escape characters that 
are illegal in a URL). nsIIOService has an Escape function, but the part I do 
not yet know how to do is the conversion to something (what?) first.

NOTE: The patch also fixes an error in the simple XLink support. Without this, 
if the value of href is "", we reload the doc.

Speed could also be optimized, for example it computes the URI every time it is 
asked for and it does not even cache the service. I do not know if this is a big 
deal, because it is still pretty fast and this is mostly needed when the user 
moves the cursor on a link or clicks a link.

What is good is that it does not add stuff to the content node. Even after 
optimization it shouldn't do this. If we want to avoid future computation we 
should probably store previously computed values into nsXMLDocument.

Comment 3

[Heikki Toivonen (remove -bugzilla when emailing directly)]

Bummer, I can't create attachments on Linux... Maybe Bugzilla is drunk. I have
created an XML file that tests XML Base and Simple XLink together.

Anyway, I noticed one case where GetXMLBaseURI hangs. Delete "continue;" and you
are set.

Comment 4

[Heikki Toivonen (remove -bugzilla when emailing directly)]

Attachment: Test case. Unpack (tar.gz), add, commit under xml/tests

Comment 5

[Heikki Toivonen (remove -bugzilla when emailing directly)]

I now have CVS account, assigning XML linking related bugs to me 
([e-mail]).

Comment 6

[Heikki Toivonen (remove -bugzilla when emailing directly)]

Patches checked in. I will still need to figure out the URL escape thing and
then I can mark this fixed.

Comment 7

[Heikki Toivonen (remove -bugzilla when emailing directly)]

I am marking this fixed although I do not think we correctly handle all illegal 
characters in URLs. In fact, I do not believe we handle them properly ANYWHERE!

After asking about this from [e-mail], he said this is what to do:

1. Get the document encoding (nsIDocument has a method for this).
2. Use the nsTextToSubURI (?) interface to ConvertAndEscape Unicode
   to URL string

I do not believe this works. First of all, the ConvertAndEscape method first 
converts the Unicode string so that it fits into char*. For this it needs the 
encoding. But what if the encoding is UTF-16? Even with UTF-8 I think this is a 
problem, because that Escape part does not know about UTF stuff. It just thinks 
all characters are between 0-255 and it does its subsitution. If we had a UTF-8 
string with a multibyte character, each byte would now be separately escaped. 
Maybe this could work, but I do not see how.

So, I did not do this. What I do is:

nsCAutoString str; 
str.AssignWithConversion(unicode_string);

and then pass that str into the NewURI functions that seem to escape illegal URL 
chars as well.

Comment 8

[Chris Petersen]

Marking verified fixed in the July 6th build.