- From: Biron,Paul V <Paul.V.Biron@kp.org>
- Date: Thu, 13 May 1999 11:44:04 -0700
- To: "'Paul Prescod'" <paul@prescod.net>
- Cc: "'www-xml-schema-comments@w3.org'" <www-xml-schema-comments@w3.org>
Sorry, forgot to include the url for the next generation forms work: [1] http://www.w3.org/MarkUp/Group/Forms/ pvb > -----Original Message----- > From: Biron,Paul V > Sent: Thursday, May 13, 1999 11:43 AM > To: 'Paul Prescod' > Cc: www-xml-schema-comments@w3.org > Subject: RE: Datatypes questions > > -----Original Message----- > From: Paul Prescod [SMTP:paul@prescod.net] > Sent: Wednesday, May 12, 1999 2:58 PM > To: Biron, Paul V; petsa@us.ibm.com; > www-xml-schema-comments@w3.org > Subject: Datatypes questions > > > "Issue (uri-scheme-facet): should we have a facet to allow a > limitation > > to a specific scheme? It might be useful to able to say that > something > > was not only a URI, but that it was a "mailto" and not a > "http://...". > > No. I think it would be in bad form to restrict by protocol. If I > invent > httpplus next week my schema should not restrict me from using it. > The > much more interesting sort of restriction is by target -- i.e. "this > link > must go to an XML element with GI foo." But that might be out of > scope. > > By "bad form" do you mean that individual type designers (and schema > authors) should steer clear of such things, and hence, we should not give > them the freedom to do so if they want to? > > The inclusion of that issue was my idea. The intention is to keep the > basic uri datatype, but to allow schema designers to create their own > user-generated subtypes which were restricted by scheme. Including this > facet would not force anyone to use it, but would merely allow those who > wanted it to be able to use it. > > The use case would be a schema author who wanted to do something like the > following in their own schema: > > <datatype name="mailto"> > <basetype name="uri"/> > <scheme>mailto</scheme> > </datatype> > <datatype name="phone"> > <basetype name="uri"/> > <scheme>tel</scheme> > </datatype> > <!-- see http://www.w3.org/Addressing/schemes for a note on the tel: > scheme --> > <elementType name="contactInfo"> > <all> > <elementType name="name"> > <datatypeRef name="string"/> > </elementType> > ... > <elementType name="phone"> > <datatypeRef name="phone"/> > </elementType> > <elementType name="email"> > <datatypeRef name="mailto"/> > </elementType> > </elementType> > > This would allow instances such as the following to be flagged as schema > invalid > > <contactInfo> > <name>Paul V. Biron</name> > <phone>tel:+1-626-685-3529</phone> <!-- valid tel: --> > <email>http://www.kp.org</email> <!-- invalid mailto: --> > </contactInfo> > > > Issue (picture-or-regex): Should the values of the > > [Lexical representation] facet be pictures, regexs, both or some > > other mechanism? > > Not only do we need both, I'm going to argue that we should be > allowed to > specify both for the same user-defined data type. Pictures are nice > and > simple. Regexps are powerful. One feature that pictures support that > regexps do not is nice, guided editing. ###-####-#### can be easily > rendered into a GUI. A regexp cannot. In the (admittedly rare) case > that a > type had both I would expect the picture to be used for guided > editing and > the regular expression for more complicated constraints. Of course > the > input would have to match both. > > Like Ashok, my initial reaction to allowing both a picture and a regex on > the same datatype is that doing so would be a bad idea. > > The intention of having the picture constraints was that it might be > simpler for some users to write (and understand) simple constraints not to > help UI builders. I'm hoping the next generation XHTML Forms work [1] > will provide the kind of UI pictures you want. > > pvb
Received on Thursday, 13 May 1999 14:52:54 UTC