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Re: Who's in charge: the markup library or the user of themark

• From: Frank Manola <fmanola@acm.org>
• To: "Costello, Roger L." <costello@mitre.org>
• Date: Mon, 24 Oct 2011 12:11:05 -0400

Roger--

It seems to me the first step in exploring this issue is for you to explain what you mean by being "in charge" or "in control".  "In charge" of what?  To what extent?  In your example, the "app" (aircraft) is also a schema, one that includes the "lib" (radio) schema.  Assuming the inclusion has been done properly (e.g., so there are no name conflicts), the radio schema is presumably going to be "in control" of any radio-related information that uses its markup, in the sense of determining validity and similar considerations (assuming that the radio schema is actually referenced for that purpose), and won't similarly be "in control" for non-radio markup.  Did you have something particular in mind?  For example, if you felt that the radio schema wasn't "in control", what evidence would you present to demonstrate that?  

--Frank

PS:  This may be just a matter of style, but I always feel uncomfortable when I hear people talking about inanimate objects like schemas "thinking" or "wanting" things.  The day that XML Schemas start to want things is the day I start seriously looking into migration to other planets.


On Oct 23, 2011, at 8:59 AM, Costello, Roger L. wrote:

> Hi Folks,
> 
> Let Lib = a library of markup.
> 
> Let App = markup that uses L.
> 
> Who's in charge: Lib or App?
> 
> EXAMPLE
> 
> Suppose Lib = an XML Schema for radios. It defines a complexType that provides a framework for radio data:
> 
> <?xml version="1.0" encoding="UTF-8"?>
> <schema xmlns="http://www.w3.org/2001/XMLSchema"
>                  targetNamespace="http://www.radio.org" 
>                  xmlns:radio="http://www.radio.org"
>                 elementFormDefault="qualified">
> 
>    <complexType name="AbstractRadioType" abstract="true">
>        <sequence>
>            <element name="name" type="string" minOccurs="0"/>
>            <element name="description" type="string" minOccurs="0"/>
>        </sequence>
>        <attribute ref="radio:id"/>
>    </complexType>
> 
>    <attribute name="id" type="ID"/>
> 
> </schema>
> 
> The creators of this schema advertise it heavily and talk about how you too can become a "radio application" (when you create a schema that uses the radio schema your schema is a radio application). The creators develop a "radio parser" that parses any XML instance document using the http://www.radio.org namespace. The creators talk about their vision of creating a worldwide web of radio applications -- a radio web.
> 
> Clearly the radio schema wants to be in control.
> 
> Now, suppose App = an XML Schema for aircrafts. One part of an aircraft is a radio, so the aircraft schema imports the radio schema and uses the AbstractRadioType complexType.  
> 
> The creators of the radio schema considers the aircraft schema to be a radio application and another member of the radio web.
> 
> Who's in charge, the aircraft schema or the radio schema?
> 
> It seems to me that it is the epitome of arrogance for the radio schema to think it is in charge. That said, perhaps I am not seeing things clearly. What do you think; is the radio schema really in charge?
> 
> /Roger
> 
> P.S. My radio example is fictitious and purely to illustrate the question.
> 

• References:
  • Who's in charge: the markup library or the user of the markuplibrary?
    • From: "Costello, Roger L." <costello@mitre.org>