Re[2]: [cgmo-webcgm] Issue: linkuri (chap 3 & chap 5) different

[Benoit Bezaire <benoit@itedo.com>]

Tuesday, April 26, 2005, 8:40:12 PM, Lofton wrote:

LH> At 04:28 PM 4/26/2005 -0400, Benoit Bezaire wrote:
LH> Hi cgmo-webcgm,

LH>   The Airbus people made me realize that Chapter 3 and 5contradict
LH>   themselves regarding linkuri (or at least that a user can easilyget
LH>   confused).

LH> IMO, potential confusion is the problem, but I don't see an actual
LH> contradiction.
I think it depends if you are in the user's context or the
implementer's context.

LH>   Section 3.2.2.3 Linkuri saysthat there are optional parts.

LH> It says:"Parameters. The data record is a SDR of one member,
LH> containingthree strings (type SF, String Fixed). The first string
LH> is the link destination, a URI, the second string (possibly null)
LH> isa Link Title parameter, and the third string is (possibly null)
LH> the Behavior parameter. Note that a null string is a zero-length
LH> string, and is not the same as an omitted parameter."

LH> I have always thought this to mean that all three parts must
LH> be present, even if part 2 and/or part 3 are empty strings.  Do
LH> you read it otherwise?
Again, if a script writer ends up reading this definition instead of
the one in chapter 5... he may get confused. It's not that clear how
you map the above wording to:
obj.setAppStructureAttr( "linkuri", ??what goes here?? );

LH> Section 5.5 says that there are no optional parts.

LH> Okay, but can part 2 and/or part 3 be an empty string?
Yes. Should this be clarified?

LH> This would allow, for example, a delimited string of:

LH> "'http://www.example.org/blah.cgm' ''  ''"
LH> or
LH> "'http://www.example.org/blah.cgm' 'Link to blah'  ''"
LH> or 
LH> "'http://www.example.org/blah.cgm' ''  '_replace'"
Yes.

LH> So all 3 parts are included, although some may consist of
LH> empty string.  Does that seem like it creates a potential
LH> problem? (I don't see it.) 
I don't think so.

LH> If not, then I think this can be consistent with 3.2.2.3, if we
LH> clarify it as such. 

LH>   It seems like the distinction between a DOM encoding of a linkuri
LH>   and the actual binary encoding isn't strong enough. We also havethe
LH>   table in section 5.7.6 that links back to 3.2.2.3 which may addto
LH>   the confusion.

LH>   Suggestions on how to clarify this?

LH>   We may want table 5.7.6 link to section 5.5 and then havesection
LH>   5.5 link to 3.2.2.3 (i.e. force people to read section5.5).

LH> That would probably help.  We should clearly distinguish that
LH> the delimited-string DOM encoding in section 5.5 and 5.7.6) is
LH> distinct from the SDR encoding of the WebCGM instance itself (SDR,
LH> as described in eachof 3.2.2.1 thru 3.2.2.10).
Yes.

LH> Btw, in 5.7.6 the example for linkuri is:
LH> "http://w3.org" "W3C"  "_blank"
LH> Shouldn't it be:
LH> '"http://w3.org" "W3C"  "_blank"'
LH> I.e., enclosed in APOSTROPHEs?
Yes and no. Apostrophes are not in section 5.5

In which context are you speaking of, DOM Strings or SDR encoding? If
I want to set the visibility on a object to 'off', I use:

obj.setAppStructureAttr( "visibility", "off" );

But the quote are required to tell the ECMAScript engine that this is
a string; the actual string value is: \o \f \f \0

If I do a get, I get back: \o \f \f \0, not \" \o \f \f \" \0

Yes, the table in insconsistent, but it's not clear if it is showing a
set string or a get string.

LH> A delimited string is a string of wsp-separated substrings,
LH> according to the grammar of  5.5.  (Same comment for 'name'.)
Yes, but it doesn't mean that '"http://w3.org" "W3C"  "_blank"' is the
actual value (the \' are not present in the actual value).

-- 
 Benoit   mailto:benoit@itedo.com

LH> Regards.
LH> -Lofton.