Re: SVG WG Last Call review of XLink 1.1

The SVG WG is fully satisfied by your responses to all our comments. Thank you. We find the spec to be usefully improved.

On Wednesday, January 18, 2006, 11:42:21 PM, Norm wrote:

NW> / Chris Lilley <chris@w3.org> was heard to say:
NW> [...]
NW> | Therefore, the wording at
NW> | http://www.w3.org/TR/2005/WD-xlink11-20050707/#markup-reqs
NW> | is very useful:
NW> |
NW> |   "2. it does not have a type attribute from the XLink namespace and it
NW> |   adheres to the conformance constraints imposed by the XLink simple
NW> |   element type, as prescribed in this specification."
NW> |
NW> | However, this text is contradicted in several places as noted below.

NW> Thank you. Those were editorial oversights and have been corrected.

NW> | 2.1) type attribute still sometimes required
NW> |
NW> | It seems that if the href attribute is *not* supplied, which is allowed
NW> | by XLink 1.1, the type="simple" must be supplied - is that intentional?

NW> Yes.

NW> | SVG WG is okay with this restriction, if it was intended, but would
NW> | prefer not to have this restrivtion.

NW> That is the way that our note about extending XLink was worded and
NW> that is how our charter was determined.

NW> I can see your point, but requiring xlink:href or xlink:type has the
NW> virtue that it does not require applications to treat

NW>   <foo/>

NW> as if it was an xlink:type="simple" link :-). I suppose we could have
NW> chosen a different wording (something along the lines of "if any
NW> attribute from the XLink namespace is used...") but we didn't. Given
NW> that a simple link without an xlink:href is likely to be uncommon, and
NW> our goal was ease of use, this seems a reasonable compromise.

NW> | 2.2) Specification text contradictory
NW> |
NW> | 4.1 XLink Attribute Usage Patterns
NW> | http://www.w3.org/TR/2005/WD-xlink11-20050707/#d0e594
NW> |
NW> | states, for simple links
NW> |
NW> |   "At least one of type or href must be specified".
NW> |
NW> | However,
NW> |
NW> | http://www.w3.org/TR/2005/WD-xlink11-20050707/#link-types
NW> |
NW> | states
NW> |
NW> |   "The value of the type attribute must be supplied."
NW> |
NW> | We assume the latter is an editorial oversight and this should in fact be
NW> | something like:
NW> |
NW> |   The value of the type attribute must be supplied, unless a simple link
NW> |   is required and an href is supplied.

NW> Exactly.

NW> | Similarly in
NW> | http://www.w3.org/TR/2005/WD-xlink11-20050707/#simple-links
NW> |
NW> |   "The XLink element for simple links is any element with an attribute
NW> |   in the XLink namespace called type with a value of "simple""
NW> |
NW> | is incorrect and is contradicted by the example that follows it. We
NW> | suggest that it should be something like
NW> |
NW> |   The XLink element for simple links is any element with either a) an
NW> |   attribute in the XLink namespace called href and no attribute in the
NW> |   XLink namespace called type, or b) an attribute in the XLink namespace
NW> |   called type with a value of "simple".

NW> Exactly.

NW> | 2.3) DTD fragment contradicts spec
NW> |
NW> | The following DTD sample from the specification
NW> |
NW> | <!ATTLIST commandname
NW> |   xlink:type      (simple|none)   #REQUIRED
NW> |   xlink:href      CDATA           #IMPLIED>
NW> |
NW> | seems to give the impression that type is required. We suggest replacing
NW> | this with a more expressive RelaxNG snippet which states that if href is
NW> | supplied, the type attribute is optional. The relevant portion of
NW> | Appendix D may be suitable:
NW> |
NW> | simple = element * {
NW> |     (simple.type | href.att | (simple.type, href.att)),
NW> |      foreign.att*, role.att?, arcrole.att?, title.att?,
NW> |      show.att?, actuate.att?,
NW> |      (anyElement | text)*
NW> |     }

NW> Indeed. Improving the examples is on my list.

NW> | 2.4) Example incorrect in 5.2
NW> | The example with the caption
NW> |
NW> |   Example: Sample simple-Type Element Declarations and Instance
NW> |
NW> | http://www.w3.org/TR/2005/WD-xlink11-20050707/#simple-links
NW> |
NW> | is incorrect.
NW> |
NW> |   xlink:role      NMTOKEN         #FIXED
NW> "http://www.example.com/linkprops/student"
NW> |
NW> | xlink:role
NW> | E The defaultValue "http://www.example.com/linkprops/student" of
NW> | attribute "xlink:role" is not legal as for the lexical constraints of
NW> | this attribute type.
NW> |
NW> | This should be CDATA not NMTOKEN

NW> Fixed.

NW> | 3) Reserving all attributes in the XLink namespace.
NW> |
NW> | This is a useful clarification.

NW> Thank you.

NW> | 4) Allowing IRIs.
NW> |
NW> | 4.1) Inadvertent text from XLink 1.1
NW> |
NW> | In section 5.4 Locator Attribute (href)
NW> | http://www.w3.org/TR/xlink/#link-locators
NW> |
NW> |   "The value of the href attribute must be an IRI reference as defined
NW> |   in [IETF RFC 3987] or must result in an IRI reference after the
NW> |   escaping procedure described below is applied."
NW> |
NW> | That text is incorrect, and seems to be the result of a search and
NW> | replace of URI for IRI. The whole point is that the escaping is not
NW> | required in the XML instance, and is defined by the IRI specification

NW> Thanks. This text is being reworked to make all the specifications in
NW> the XML family consistent in this regard. It will be fixed in the next
NW> draft.

NW> Please let us know if you are satisfied by these resolutions to your
NW> issues.

NW>                                         Be seeing you,
NW>                                           norm





-- 
 Chris Lilley                    mailto:chris@w3.org
 Chair, W3C SVG Working Group
 W3C Graphics Activity Lead
 Co-Chair, W3C Hypertext CG

Received on Tuesday, 28 March 2006 22:52:32 UTC