Fw: [dfdl-wg] F2F status on discussions here about Scoping #2

Wed Oct 5 11:47:04 CDT 2005

----- Forwarded by Steve Hanson/UK/IBM on 05/10/2005 17:46 -----

             Steve                                                         
             Hanson/UK/IBM                                                 
                                                                        To 
             05/10/2005 17:46          Mike Beckerle/Worcester/IBM         
                                                                        cc 
                                       Geoff Judd/UK/IBM, Suman            
                                       Kalia/Toronto/IBM at IBMCA             
                                                                   Subject 
                                       Fw: [dfdl-wg] F2F status on         
                                       discussions here about Scoping #2   

I think I see what selectors solve. It's the embedded message scenario
where I have a different format, and hence configuration, for the embedded
message. I can use selectors to pull together multiple different
configurations in a single parse. Correct?

Regards, Steve

Steve Hanson
WebSphere Business Integration Brokers,
IBM Hursley, England
Internet: smh at uk.ibm.com
Phone (+44)/(0) 1962-815848
----- Forwarded by Steve Hanson/UK/IBM on 05/10/2005 12:27 -----

             Steve                                                         
             Hanson/UK/IBM                                                 
                                                                        To 
             05/10/2005 12:18          Mike Beckerle <beckerle at us.ibm.com> 
                                                                        cc 
                                       Geoff Judd/UK/IBM, Suman            
                                       Kalia/Toronto/IBM at IBMCA             
                                                                   Subject 
                                       Re: [dfdl-wg] F2F status on         
                                       discussions here about Scoping      
                                       (Document link: Steve Hanson)       

Hi, I've taken a look through the slides, looks like you had a productive
day. The scheme looks ok in principle, but I can't glean from the foils
exactly how the selector mechanism works, and (consequently) why we can't
achieve the same result using configuration blocks alone. I'm not trying to
be awkward here, just trying to justify to myself why we need the extra
complexity selectors introduce. It would be great if we could rubber stamp
scoping by the end of the call today.

What would be really helpful for the call would be to mail out a single
DFDL schema that used configurations and selectors to model the following
COBOL message and its equivalent tagged/delimited form. As a comparison,
here's a DFDL schema that models this just using configurations. This works
because the extends attribute is mandatory on any dfdl element if more than
one configuration is defined.

1  MESSAGE
      5   STR-FIELD                       PIC X(10)
<----------- logical string length 10
      5   INT-FIELD                         PIC 9(8) COMP
<----------- logical integer, physical integer length 4
      5   DEC-FIELD                       PIC 9999V99  DISPLAY
<----------- logical decimal, physical extended decimal length 6 with VDP 2

Tagged/delimited example instance using postfix delimiters
<MSG><STR>Example;<INT>4000;<DEC>9999.99;<END>

<dfdl:configuration name="cobol" repType="binary" ...... />

<dfdl:configuration name="tagged" repType="text" ...... />

<xsd:element name="message">
      <xsd:annotation>
            <xsd:appinfo source="http://dataformat.org">
                  <dfdl:defaults>
                        <dfdl:configuration extends="cobol" charset="937"
byteOrder="bigEndian" />
                        <dfdl:configuration extends="tagged" charset="850"
/>
                  <dfdl:defaults>
            </xsd:appinfo>
      </xsd:annotation>
      <xsd:complexType>
            <xsd:sequence>
                  <xsd:annotation>
                        <xsd:appinfo source="http://dataformat.org">
                              <dfdl:sequence extends="tagged"
initiator="<MSG>" terminator="<END>" separator=";" separatorType="postfix"
/>
                        </xsd:appinfo">
                  </xsd:annotation>
                  <xsd:element name="str_field" xsd:type="string">
                        <xsd:annotation>
                              <xsd:appinfo source="http://dataformat.org">
                                    <dfdl:string extends="cobol"
baseWidth="10" />
                                    <dfdl:string extends="tagged"
initiator="<STR>" />
                              </xsd:appinfo>
                        </xsd:annotation>
                  </xsd:element>
                  <xsd:element name="int_field" xsd:type="int">
                        <xsd:annotation>
                              <xsd:appinfo source="http://dataformat.org">
                                    <dfdl:int extends="cobol" baseWidth="4"
/>
                                    <dfdl:int extends="tagged"
initiator="<INT>" />
                              </xsd:appinfo>
                        </xsd:annotation>
                  </xsd:element>
                  <xsd:element name="string" xsd:type="decimal">
                        <xsd:annotation>
                              <xsd:appinfo source="http://dataformat.org">
                                    <dfdl:decimal extends="cobol"
baseWidth="6" virtualDecimalPoint="2" />
                                    <dfdl:decimal extends="tagged"
initiator="<DEC>" virtualDecimalPoint="2" />
                              </xsd:appinfo>
                        </xsd:annotation>
                  </xsd:element>
            </xsd:sequence>
      </xsd:complexType>
</xsd:element>

Regards, Steve

Steve Hanson
WebSphere Business Integration Brokers,
IBM Hursley, England
Internet: smh at uk.ibm.com
Phone (+44)/(0) 1962-815848

             Mike Beckerle                                                 
             <beckerle at us.ibm.                                             
             com>                                                       To 
             Sent by:                  dfdl-wg at gridforum.org               
             owner-dfdl-wg at ggf                                          cc 
             .org                                                          
                                                                   Subject 
                                       [dfdl-wg] F2F status on discussions 
             05/10/2005 03:08          here about Scoping                  

Attached are slides we'll review as a group tomorrow. Could be typos in
these. I did them rather fast.

[attachment "ggf15-dfdl-wg-f2f-scoping-summary.ppt" deleted by Steve
Hanson/UK/IBM]