[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] RE: A bunch of components, but no mandated organization - reas
> -----Original Message----- > From: Nathan Young [mailto:natyoung@c...] > Sent: Wednesday, January 12, 2005 1:38 PM > To: Roger L. Costello; 'XML Developers List' > Subject: Re: A bunch of components, but no mandated > organization - reasonable? > > Hi. > > > Suppose that: > > > > 1. There exist a collection of "components", and each component is > > well-defined and understood. > > > > 2. There does NOT exist any rules which specify how the components > > should be assembled. > > Either no relation exists between the information (and I > don't think this is what you mean) or there are some rules > relating the pieces of information and it boils down to > questions about how to represent and communicate the relationships: > > - the document structure could imply information about the > relationships of the > information > - a supplemental structured document could hold information > about relationships > (meta data) > - your systems and my systems could both implement the same > sets of rules about > relationships > > In all three cases but especially in the third, some > out-of-band communication is often needed to establish a > working relationship where we agree on the meaning of > components and their relationships. Na ah - how about inference engines, acting on the information that is semantically marked-up using RDF or OWL? > > Can information be transmitted in a world where the building blocks > > are understood, but no grammar exists? > > I'm not sure that I see a case where building blocks exist > without a grammar. You always need rules to assemble the > blocks, then rules to assemble the assemblies. The smaller > you break the blocks up, the simpler the rules get, but you > still need to express something about the information. You > can mark it up or use a schema or tell me what it is over the > phone or whatever. > > Is a grammar necessary for information transfer? > > You certainly don't have to explicitly model every > relationship that your recipient may be interested in. > That's what queries (transforms) are often used for. > > > Consider XML Schemas. Suppose that: > > > > 1. An XML Schema declares a bunch of independent elements (i.e., > > components) > > and each component is understood. For example, here's a > Book component: > > > > <xsd:element name="Book"> > > <xsd:complexType> > > <xsd:all> > > <xsd:element name="Title" type="xsd:string"/> > > <xsd:element name="Author" type="xsd:string"/> > > <xsd:element name="Date" type="xsd:date"/> > > <xsd:element name="ISBN" type="xsd:string"/> > > <xsd:element name="Publisher" type="xsd:string"/> > > </xsd:all> > > </xsd:complexType> > > </xsd:element> > > > > Here's a BookCover component: > > > > <xsd:element name="BookCover"> > > <xsd:complexType> > > <xsd:choice> > > <xsd:element > > name="Hardcover"><xsd:complexType/></xsd:element> > > <xsd:element > > name="Softcover"><xsd:complexType/></xsd:element> > > </xsd:choice> > > </xsd:complexType> > > </xsd:element> > > > > Everyone understands the meaning of each component in the Schema. > > > > 2. But there is no declaration tying the components together, e.g., > > there is no overarching element declaration that relates the Book > > component with the BookCover component. > > > > If I create an XML instance document using the components > and send the > > instance document to you, will you be able to understand my data? > > If you are saying that the only way to have an agreement > about this is to code it into the XSD then I'm not sure I > agree. I do think you have demonstrated that it's possible > to model books and cover types in a way that makes it > unnaturally difficult to relate the two. I think Roger is asking a much simpler question than that, which is can the information be understood if there is no relation between the two. If we are talking about machine-to-machine communication, I believe the answer is yes - if, for instance, one uses xml:id's (which would not involve an overarching element declaration, as Roger describes). Kind Regards, Joseph Chiusano Booz Allen Hamilton Strategy and Technology Consultants to the World > -------->Nathan > > > > > > /Roger > > > > > > > > > > ----------------------------------------------------------------- > > The xml-dev list is sponsored by XML.org <http://www.xml.org>, an > > initiative of OASIS <http://www.oasis-open.org> > > > > The list archives are at http://lists.xml.org/archives/xml-dev/ > > > > To subscribe or unsubscribe from this list use the subscription > > manager: <http://www.oasis-open.org/mlmanage/index.php> > > > > > > -- > > > .:||:._.:||:._.:||:._.:||:._.:||:._.:||:._.:||:._.:||:._.:||:. > _.:||:._.:||:. > > Nathan Young > A: ncy1717 > E: natyoung@c... > > ----------------------------------------------------------------- > The xml-dev list is sponsored by XML.org > <http://www.xml.org>, an initiative of OASIS > <http://www.oasis-open.org> > > The list archives are at http://lists.xml.org/archives/xml-dev/ > > To subscribe or unsubscribe from this list use the subscription > manager: <http://www.oasis-open.org/mlmanage/index.php> > >
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