RE: [xri-editors] Xref escaping rules

["Dave McAlpin" <dave.mcalpin@epokinc.com>]

Sorry, I misunderstood the question. I'm allowing both in the normative text
and saying the second is preferred.

-----Original Message-----
From: Wachob, Gabe [mailto:gwachob@visa.com] 
Sent: Monday, June 30, 2003 1:35 PM
To: 'Dave McAlpin'; Wachob, Gabe; 'Drummond Reed';
xri-editors@lists.oasis-open.org
Subject: RE: [xri-editors] Xref escaping rules

Really? 

So you'd prefer:

xri://foo.bar/(+Gabe/#28+stuff#29)

over

xri://foo.bar/(+Gabe/(+stuff))

I don't see a reason why we need to do escaping for the () on XRI values as
cross references.. 

	-Gabe

> -----Original Message-----
> From: Dave McAlpin [mailto:dave.mcalpin@epokinc.com]
> Sent: Monday, June 30, 2003 12:48 PM
> To: 'Wachob, Gabe'; 'Drummond Reed'; xri-editors@lists.oasis-open.org
> Subject: RE: [xri-editors] Xref escaping rules
> 
> 
> I think these rules apply to cross-references in general, 
> both general URIs
> and XRIs.
> 
> -----Original Message-----
> From: Wachob, Gabe [mailto:gwachob@visa.com] 
> Sent: Monday, June 30, 2003 12:05 PM
> To: 'Dave McAlpin'; Wachob, Gabe; 'Drummond Reed';
> xri-editors@lists.oasis-open.org
> Subject: RE: [xri-editors] Xref escaping rules
> 
> Dave-
> 	This seems straightforward and I don't know why it 
> wasn't the first
> proposal on the table. I can't seem to figure out a problem 
> with it, so +1
> unless someone can discover an issue with it.
> 
> 	BTW, the way I read it is that this escaping is only 
> neccesary for
> URIs as xrefs, not XRI values as xrefs...
> 
> 	-Gabe
> 
> > -----Original Message-----
> > From: Dave McAlpin [mailto:dave.mcalpin@epokinc.com]
> > Sent: Monday, June 30, 2003 10:08 AM
> > To: 'Wachob, Gabe'; 'Drummond Reed'; 
> xri-editors@lists.oasis-open.org
> > Subject: RE: [xri-editors] Xref escaping rules
> > 
> > 
> > I assumed we would escape iteratively, once for each level 
> of nesting
> > 
> > 1) Embed http://foo.com?id=21#bar in xri:@foo/baz as a 
> cross-reference
> > 
> > a) Escape cross-reference to get
> > http://foo.com%3Fid=21%23bar
> > 
> > b) Add as cross-reference
> > xri:@foo/baz/(http://foo.com%3Fid=21%23bar)
> > 
> > When the cross-reference is extracted, it's unescaped to
> > 
> > http://foo.com?id=21#bar
> > 
> > 2) Embed http://foo.com?id=21-%28widget#bar in xri:@foo/baz as a
> > cross-refrence
> > 
> > a) Escape the cross-reference to get
> > http://foo.com%3Fid=21-%2528widget%23bar
> > 
> > b) Append as cross-reference
> > xri:@foo/baz/(http://foo.com%3Fid=21-%2528widget%23bar)
> > 
> > When the cross-reference is extracted, it's unescaped to
> > 
> > http://foo.com?id=21-%28widget#bar
> > 
> > 3) A complex nested example. Embed http://foo.com?id=21-%28widget in
> > xri:+foo.bar.<xref>, which is in turn embedded in 
> > xri://foo.bar/<xref>/baz
> > 
> > a) First escape the innermost cross-reference to get
> > http://foo.com%3Fid=21-%2528widget
> > 
> > b) Add as cross-reference
> > xri:+foo.bar.(http://foo.com%3Fid=21-%2528widget)
> > 
> > c) Escape the cross-reference to get
> > xri:+foo.bar.(http://foo.com%253Fid=21-%252528widget)
> > 
> > d) Add as cross-reference
> > xri://foo.bar/(xri:+foo.bar.(http://foo.com%253Fid=21-%252528w
> > idget)))/baz
> > 
> > When the XRI is evaluated, the outermost cross-reference is 
> extracted
> > 
> > xri:+foo.bar.(http://foo.com%253Fid=21-%252528widget))
> > 
> > And unescaped to give
> > 
> > xri:+foo.bar.(http://foo.com%3Fid=21-%2528widget))
> > 
> > The next level cross-reference is extracted
> > 
> > http://foo.com%3Fid=21-%2528widget
> > 
> > and unescaped to give 
> > 
> > http://foo.com?id=21-%28widget
> > 
> > Dave
> > 
> > -----Original Message-----
> > From: Wachob, Gabe [mailto:gwachob@visa.com] 
> > Sent: Monday, June 30, 2003 9:19 AM
> > To: 'Drummond Reed'; xri-editors@lists.oasis-open.org
> > Subject: RE: [xri-editors] Xref escaping rules
> > 
> > Drummond-
> > 	This seems pretty reasonable. 
> > 
> > 	Have you considered the case where you have two levels of cross
> > referencing? That is, a cross reference which contains an XRI 
> > value that
> > itself has a cross reference? 
> > 
> > xri://foo.bar/(+foo.bar.(http://www.foo.com#3ffoo))/baz
> > 
> > vs
> > 
> > xri://foo.bar/(+foo.bar.(http://www.foo.com(#3f)foo))/baz
> > 
> > vs
> > 
> > xri://foo.bar/(+foo.bar.(http://www.foo.com((#3f))foo))/baz
> > 
> > I think you need to amend the rules about escaping/unescaping 
> > to account for
> > nesting.. 
> > 
> > 	-Gabe
> > 
> > 
> > > -----Original Message-----
> > > From: Drummond Reed [mailto:drummond.reed@onename.com]
> > > Sent: Sunday, June 29, 2003 1:15 PM
> > > To: xri-editors@lists.oasis-open.org
> > > Subject: [xri-editors] Xref escaping rules
> > > 
> > > 
> > > Here's the escaping proposal that I brought up on the 
> last TC call.
> > >  
> > > The issue is that an XRI or URI is used as a cross-reference 
> > > may contain
> > > characters that must be escaped in order to conform with 2396.
> > > Specifically:
> > >  
> > > * "?" may not appear until the start of the one-and-only 
> > query segment
> > > allowed by 2396.
> > > * The same is true with "#" for fragments
> > > * Lastly, an UNMATCHED opening or closing paren must be 
> > > escaped or else
> > > the cross-reference will not parse correctly. (Note that 
> > > MATCHED opening
> > > and closing parens inside do not need escaping because they 
> > represent
> > > either a second-level nested cross-reference or a parenthetically
> > > enclosed string in a native URI but either way will not be 
> > ambiguous.)
> > >  
> > > However we can't use just 2396 escaping rules (i.e., "%xx" 
> > where xx is
> > > the hex value of the character) for these four characters 
> > > because it if
> > > the embedded XRI or URI contained those same escape sequences 
> > > natively,
> > > it would be ambiguous which to unescape and not to 
> unescape when the
> > > cross-reference is extracted. For example, if a URI already 
> > contained
> > > the escape sequence %3F (the "?" character) before it was 
> > > turned into a
> > > cross-reference, how would the parser know NOT to unescape it when
> > > extracting the cross-reference?
> > >  
> > > The proposed solution is to apply two special escaping 
> rules to any
> > > URI/XRI string being embedded as a cross-reference. They must 
> > > be applied
> > > in the following order:
> > >  
> > > 1) Parse the string to find any instance of "%3F", "%23", 
> "%28", or
> > > "%29" and enclose these in parens. Example: "(%3F)".
> > > 2) Escape any "?", "#", or UNMATCHED paren as per 2396 escaping.
> > > Example: a URI that contained a query would have the "?" 
> turned into
> > > %3F.
> > >  
> > > To extract a cross-reference, apply the same two rules in 
> > > reverse, i.e.:
> > >  
> > > 1) From the extracted cross-reference, escape any instance of 
> > > %3F, %23,
> > > %28, or %29 EXCEPT those enclosed in parens.
> > > 2) For any instance of "%3F", "%23", "%28", or "%29" enclosed 
> > > in parens,
> > > remove the parens.
> > >  
> > > Example: 
> > >  
> > > Embed: URI "http://foo.com/?id=21#bar" in XRI "xri:@foo/baz/"
> > > Result: "xri:@foo/baz/(http://foo.com/%3Fid=21%23bar)"
> > >  
> > >  
> > > Embed: URI "http://foo.com/?id=21-%28widget#bar" in XRI 
> > > "xri:@foo/baz/"
> > > Result: "xri:@foo/baz/(http://foo.com/%3Fid=21-(%28)widget%23bar)"
> > >  
> > > Does this work for everyone? Any other proposals?
> > >  
> > > =Drummond 
> > >  
> > >  
> > >  
> > >  
> > > 
> > > 
> > 
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