S1000D and CGM Dieter Weidenbrueck Paris July 21, 2004

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S1000D and CGMDieter WeidenbrueckParis July
21, 2004
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Content

• Current problems with profile usage
• Suggestion for new S1000D profile
• Cascading CGM Profiles
• The new XML Companion File Architecture
• The WebCGM DOM

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Current Problems with CGM Profile

• A CGM file is GREXCHANGE compliant if it follows
  the rules described in the ATA specification
• This is expressed in the metafile descriptor
  string
• MFDESC '"ProfileIdATA GRAPHICS.GREXCHANGE",
  "ProfileEd2.6"
• Such a file can be tested against GREXCHANGE 2.6

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Current Problems with CGM Profile

• S1000D specifies in 7.3.2, 5.0
• S1000D CGM V4 Profile
• S1000D specifies in 7.3.2, 1.2
• S1000D restrictions of and extensions to the ATA
  TIFF and CGM profile GREX V2.6 or later are
  detailed in Para 5.2 below.
• This is not enough to define a valid profile.

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Current Problems with CGM Profile

• One example BEGIN METAFILE
• The ATA specific notation and limitation of the
  BEGIN METAFILE parameter value identifying a CGM
  graphic through the ATA GNBR (see 5-2-4.7.2.3,
  table entry T.15.1, of ATA iSpec 2200) shall be
  interpreted to hold the S1000D ICN in the form
  "ICN-icn". The ATA fixed parameter length of 32
  bytes has to be abandoned as above for raster
  graphics.
• So according to S1000D, the following is legal
• BEGMF 'ICN-1B-B-291101-M-C0419-00571-A-01-1'
• According to ATA GREXCHANGE, it is not.

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Current Problems with CGM Profile

• Additional problem
• GREXCHANGE 2.6 or later
• This leads to further ambiguity. GREXCHANGE is
  at 2.9 right now.

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Current Problems with CGM Profile

• The Metafile Descriptor String does not contain
  any information that this file is compliant to
  the S1000D Profile.
• Thus a validator can only test against the
  GREXCHANGE profile, and fail
• The current situation does not allow for the
  creation of testable S1000D-compliant CGM files.

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Suggestion

• The EPWG has several choices
• Go with WebCGM without changes
• Go with GREXCHANGE without changes
• Write an S1000D profile
• ltwaves of enthusiasm crossing the room/gt

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Cascading CGM Profiles
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The current way

• CGM1999 defines rules for profiles
• Complete Profile Pro-Forma (PPF) referencing the
  Model Profile (MP).
• The PPF is a huge table with about 200 rows
• ATA GREXCHANGE profile is a complete PPF, with a
  most rows identical to the MP, and a relative
  handful of difference rows
• S1000D references ATA GREXCHANGE with a handful
  of differences

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The Motivation

• Almost nobody wants to write a full PPF
• (including the CGM geeks)
• There are only minimal changes between the
  profiles as far as graphics is concerned
• Most differences relate to metadata

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The Concept

• WebCGM is a solid generic technical graphics
  profile for the web
• It is a full PPF
• It provides a good foundation for the creation of
  other profiles
• Other profiles could be defined by a delta PPF
  from WebCGM

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The Concept

• WebCGM is defined by reference to MP (in a full
  PPF)
• ATA could be defined by a delta-PPF reference to
  WebCGM
• This is very likely to happen soon
• S1000D could be defined by a delta-PPF reference
  to either WebCGM or ATA

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The Concept

• By following links through the cascade, any item
  in any profile can be discovered
• Using a regularized markup grammar for the PPF
  (XHTML), it would be possible to generate a full
  PPF for any profile along the cascade

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Benefits

• Creating a profile becomes a straightforward
  process
• If it is based on WebCGM with minimal graphic
  changes, implementations are very likely to
  happen
• If WebCGM is revised, the derived profile could
  issue a new version as well and inherit the
  changes

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The New XML Companion File Architecture
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Current situation

• XML Companion Files have been discussed for
  several years
• No standardization yet
• Binding between objects in CGM and XML is unclear
• Viewer behavior is undefined

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The Concept

• CGM Open has defined a complete architecture for
  XML companion files
• Extendable DTD
• Viewer behavior
• DOM accessibility

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Example 1

• lt?xml version"1.0" encodingUTF-16) ?gt
• ltwebcgm version"1.0" filename"abc.cgm"gt
• ltgrobject apsid"myObj1"
  screentip"This is object 1."gt
• ltlinkuri uri"http//www.cgmopen.org"
  behavior"_blank"/gt
• lt/grobjectgt
• lt/webcgmgt
• Binding between APS ID in CGM and apsid on XML
  object

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Example 2

• lt?xml version"1.0" encodingUTF-16) ?gt
• ltwebcgm version"1.0" filename"abc.cgm"gt
• ltbindByName apstargetname"myName1"
  screentip"This is object 1."gt
• ltlinkuri uri"http//www.cgmopen.org"
  behavior"_blank"/gt
• lt/bindByNamegt
• lt/webcgmgt
• Binding between APS name in CGM and apstargetname
  on XML object

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Example 3

• lt?xml version"1.0" encodingUTF-16) ?gt
• ltwebcgm version"1.0" filename"abc.cgm"
  xmlnss1000dns"http//namespace_declaration"gt
• ltgrobject apsid"myObj1"
  screentip"This is object 1.
  s1000dnsviewcontext"5 5 25 25"gt
• lts1000dnshotspot id"myHSID"
  apsid"myObj1 apsname"myName1"
• coords"10 10 20 20"/gt
• ltlinkuri uri"http//www.cgmopen.org"
  behavior"_blank"/gt
• lt/grobjectgt
• lt/webcgmgt
• Extending the DTD using namespaced attributes and
  elements

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Example 4

• lt?xml version"1.0" encodingUTF-16) ?gt
• ltwebcgm version"1.0" filename"abc.cgm"
  xmlnss1000dns"http//namespace_declaration"gt
• ltbindByName apstargetname"myName1"
  screentip"This is object 1.
  s1000dnsviewcontext"5 5 25 25"gt
• lts1000dnshotspot id"myHSID"
  apsid"myObj1 apsname"myName1"
• coords"10 10 20 20"/gt
• ltlinkuri uri"http//www.cgmopen.org"
  behavior"_blank"/gt
• lt/bindByNamegt
• lt/webcgmgt
• Extending the DTD using namespaced attributes and
  elements

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Viewer behavior

• The CGM loads the CGM file first
• The CGM viewer will then load the content of the
  XML file and apply it to the CGM content
• The application can access any detail of the
  companion file content using DOM functions

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Example

• ltscript type"text/javascript"gt
• var cgmDoc document. myCGMViewer.GetWebCGMDoc
  ument()
• cgmDoc.firstPicture.applyCompanionFile("comp.xm
  l")
• lt/scriptgt
• The CGM viewer now holds all information in
  memory.
• Access is possible using DOM functions

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Summary

• CGM Open publishes standard WebCGM DTD
• Other organizations can derive their own DTD from
  it
• Loading and access to details stored in the XML
  companion file will be standardized as well

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Finally - The WebCGM DOM
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The WebCGM DOM Overview

• Interfaces to access all application structures
  and their attributes
• Some limited styling at APS level possible
• Colors
• Line weights
• Text fonts
• DOM Event Model

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Fundamental interfaces

• Metafile
• Picture
• AppStructure
• Attr
• Text

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Important functionality

• Traversal of DOM tree
• Access to all APSs and their attributes
• Access to all namespaced attributes and elements
  loaded from a companion file
• DOM Event model for mouse events

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Availability

• WebCGM DOM and Companion File Architecture will
  go to feature freeze on August 11, 2004
• This work plus some other changes will become
  WebCGM 2.0
• CGM Open will work with W3C to publish WebCGM 2.0
  as a Recommendation asap
• Technical work is expected to finish in 2004

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CGM Open Recommendations for S1000D

• If possible,
• create an S1000D profile using the cascading
  profile technique
• develop an S1000D companion file DTD based on the
  WebCGM DTD
• build applications using the WebCGM DOM

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Credits

• CGM Open
• Dave Cruikshank, Boeing (DTDs)
• Lofton Henderson (Cascading Profiles)
• Benoit Bezaire, ITEDO (WebCGM DOM, XML Companion
  Files)

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Q A