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Re: Feeback on tutorials

From: Chris Lilley <chris@w3.org>
Date: Wed, 1 Jun 2005 21:19:47 +0200
Message-ID: <1809985910.20050601211947@w3.org>
To: Felix Sasaki <fsasaki@w3.org>
Cc: GEO <public-i18n-geo@w3.org>

On Wednesday, June 1, 2005, 6:59:29 PM, Felix wrote:

FS> - "Various document formats already support IRIs. Examples include HTML
FS> 4.0, XML (system identifiers), the XLink href  attribute, XML Schema's
FS> anyURI datatype,": Unfortunately this is not true, as I had to realize
FS> myself while reviewing QT: anyURI does not support IRI directly yet, it
FS> still refers to XLink 1.0

Which is most of IRI, apart from the international domain names. It has
all the "utf-8 and hexify" stuff.

and XLink 1.1 should fix that
http://www.w3.org/TR/2005/WD-xlink11-20050428/

  3.1 Processing Dependencies

  XLink processing depends on [XML], [XML Names], [XML Base], and [IETF
  RFC 3987].

and

  The value of the href attribute must be an IRI reference as defined in
  [IETF RFC 3987] or must result in an IRI reference after the escaping
  procedure described below is applied. (By design, all URIs (Uniform
  Resource Identifiers) as defined in [IETF RFC 3986] are also IRIs.)

  XLink 1.0 described a procedure for escaping characters found in the
  href attribute value that were not allowed in URIs. For XLink 1.1,
  those details are normatively described in Section 3.1 of [IETF RFC
  3987]. However, for backwards compatibility, XLink 1.1 processors must
  escape one additional character, the space. All occurrences of a space
  in the value of an href attribute must be replaced by %20.

/me wonders about that last sentence.

FS> - "Unfortunately, not so many protocols allow IRIs to pass through 
FS> unchanged.": Why unfortunately? The mapping from IRI to URI is 
FS> reversible,

But comparisons before and after the mapping do not yield identity. Also
it would be easier if the mapping was not needed. So "unfortunately" is
reasonable there.

FS> and the protocols you mention have good reasons for the 
FS> ASCII-escaping; the IRI spec itself mentions HTTP:  "The intent is not
FS> to introduce IRIs into contexts that are not defined to accept them.
FS> For example, XML schema [XMLSchema] has an explicit type "anyURI" that
FS> includes IRIs and IRI references. Therefore, IRIs and IRI references can
FS> be in attributes and elements of type "anyURI".  On the other  hand, in
FS> the HTTP protocol [RFC2616], the Request URI is defined as a URI, which
FS> means that direct use of IRIs is not allowed in HTTP requests. "

Right. Are there any protocols that accept IRI without mapping?



-- 
 Chris Lilley                    mailto:chris@w3.org
 Chair, W3C SVG Working Group
 W3C Graphics Activity Lead
Received on Wednesday, 1 June 2005 19:19:55 UTC

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