RE: [xml-dev] A bunch of components, but no mandated organization - reasonable?

["Chiusano Joseph" <chiusano_joseph@bah.com>]

> -----Original Message-----
> From: Roger L. Costello [mailto:costello@mitre.org] 
> Sent: Wednesday, January 12, 2005 8:45 AM
> To: 'XML Developers List'
> Subject: [xml-dev] A bunch of components, but no mandated 
> organization - reasonable?
> 
> Hi Folks,
> 
> 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.
> 
> If I assemble some of the components into a certain 
> structure, and send the structure to you, will you be able to 
> understand my structure?

Regarding the multiple references to "you": Is "you" a person, or a
machine, or both?

Kind Regards,
Joseph Chiusano
Booz Allen Hamilton
Strategy and Technology Consultants to the World
 
> Let me be a bit more concrete.  Suppose that:
> 
> 1. There exist a collection of information components, and 
> each information component is well-defined and understood.  
> Some examples of information components might include - a 
> missile information component (this component provides 
> information about a missile, such as its direction, speed, 
> warhead type, etc), an aircraft information component (this 
> component provides information about an aircraft, such as its 
> altitude, wingspan, speed, etc).
> 
> 2. There does NOT exist any rules which specify how the 
> information components should be assembled.  In other words, 
> there is no grammar which dictates how the components must be 
> bound together.
> 
> If I assemble some of the information components into a 
> certain structure, and send the structure to you, will you be 
> able to understand my information structure?
> 
> Can information be transmitted in a world where the building 
> blocks are understood, but no grammar exists?
> 
> Is a grammar necessary for information transfer?
> 
> Let me give a simple example.  Suppose that:
> 
> 1. There exists these three components - A, B, C.  And 
> everyone knows the meaning of each component.
> 
> 2. There are no rules that specify how A, B, or C should be 
> organized, nor the number of occurrences of each.
> 
> Suppose that I create this message: AACABBAC.  And I send it 
> to you.  Will you be able to understand my message?
> 
> Consider the English language.  Suppose that:
> 
> 1. The English language was just comprised of a bunch of 
> words (and each word is understood), ...
> 
> 2. ... but there was no English grammar.
> 
> If I compose a sentence using these words, will you be able 
> to understand my sentence? 
> 
> 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? 
> 
> /Roger 
> 
> 
> 
> 
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