W3C

WebCGM 2.0 Recommendation Errata

This version:
http://www.w3.org/2006/WebCGM20-errata.html
This document records known errors in the document:
http://www.w3.org/TR/2007/REC-webcgm20-20070130/
Latest WebCGM 2.0 version:
http://www.w3.org/TR/webcgm20/

Last modified: $Date: 2007/11/12 08:52:13 $


About the WebCGM 2.0 Recommendation

The WebCGM 2.0 Recommendation has been produced by the W3C WebCGM Working Group as part of the activity of the W3C Interaction Domain.

This document lists the known errata to the WebCGM 2.0 Recommendation.
Each entry has the following information:

Please send general comments about this document to the public mailing list public-webcgm@w3.org. An archive is available at http://lists.w3.org/Archives/Public/public-webcgm/.

Conventions

Added text marked thus. Removed text marked thus. Changed text marked thus.

The processing of errata is governed by the errata process defined in the W3C Process document.

Status of the errata

For all errata listed on this page, it is the consensus of the WebCGM Working Group that they are correct and appropriate. They are not to be considered normative until approved by a Call for Review of Proposed Corrections or a Call for Review of an Edited Recommendation.


Known errors as of November 2007

  1. E01: editorial errors in WebCGM 2.0 XCF DTD
  2. E02: "inherit" value missing from DTD snippet in XCF 'grobject' definition
  3. E03: ambiguous applicability of "1024" limit in CLOSED FIGURE (PPF)
  4. E04: ambiguity on position of radius in degenerate elliptical arc close
  5. E05: wrong case in 'apsId' usage in example 5.1b
  6. E06: case insensitivity of <param> attribute values
  7. E07: typo in LINE TYPE entry in PPF

Rejected proposed errata:

  1. None

Proposed Errata:

- E01: editorial errors in WebCGM 2.0 XCF DTD.

Description:

Date of this entry: 07 March 2007
(latest editorial corrections: 12 June 2007)

Class: Class 2.

These are considered to be editorial errors ("minor typographical correction"). In all cases they represent either editorial deviation of one piece of DTD code from its normative repetition in another place, or else failure to update DTD code to match normatively documented functionality in another place. The WebCGM WG believes that conformance of implementations is unaffected.

Overview: There are three interrelated editorial errors (see "Bug details" below) in the external DTD file ([4], [5]) that was published on 2007-01-30 concurrently with the publication of REC WebCGM 2.0 [2].

[2] http://www.w3.org/TR/2007/REC-webcgm20-20070130/

The WebCGM 2.0 XCF chapter [3] defines a System Identifier (SI) whose associated URI is [4], which resides in OASIS web space. The URI [4] is viewed as the "latest version" URI for the DTD. It now points via a symlink to a specific version [5], in which you will see the error(s).

[3] http://www.w3.org/TR/2007/REC-webcgm20-20070130/WebCGM20-XCF.html#namespace
[4] http://docs.oasis-open.org/webcgm/v2.0/webcgm20.dtd
[5] http://docs.oasis-open.org/webcgm/v2.0/OS/webcgm20.dtd

Bug details: The three-part error in the 20070130-published DTD [5] is:

E01.1: line 92, after "desc CDATA #IMPLIED" there is a stray ">". Proposed Correction: delete stray ">".

E01.2: line 93, the string "%linkuriAttExt;" has "Ext" capitalized instead of "EXT" upper case. Proposed Correction: change "Ext" to "EXT".

E01.3: line 43, the entity definition of "linkuriEXT" is "" instead of "EMPTY". Proposed Correction: change the 2-character string "" to the 7-character string "EMPTY".

In theWebCGM 2.0 REC text [6], the glitches E01.1 and E01.2 are not repeated. However the glitch E01.3 is repeated in 4.3.8 and 4.4 [6], in the in-text listing of the DTD snippets and in the in-text complete DTD:

[6] http://www.w3.org/TR/2007/REC-webcgm20-20070130/WebCGM20-XCF.html

E01.4: section 4.3.8: in the DTD snippet, the entity definition of "linkuriEXT" is "" instead of "EMPTY". Proposed Correction: change the 2-character string "" to the 7-character string "EMPTY".

E01.5: section 4.4: in the complete DTD, the entity definition of "linkuriEXT" is "" instead of "EMPTY". Proposed Correction: change the 2-character string "" to the 7-character string "EMPTY".

WG-approved Resolution:

At its 20070308 teleconference, the WebCGM WG has approved and endorsed the following resolutions. (Subsequent updates to this erratum have been purely editorial.)

The DTD-code correction of the errors E01.1-E01.3 above is found in the file [7]:

[7] http://docs.oasis-open.org/webcgm/v2.0/errata/os/webcgm20-20070509.dtd

This is the approved DTD correction file of the coordinated OASIS errata processing for this bug.

Two changes to the text of WebCGM 2.0 REC are also approved and endorsed, as specified in E01.4 and E01.5 above.

- E02: "inherit" value missing from DTD snippet in XCF 'grobject' definition

Date of this entry: 07 September 2007
(Most recent update: 07 November2007)

Class: Class 2.

Overview:

In the XCF DTD snippet for the 'grobject' element (section 4.3.5), the attribute declaration for the 'visibility' attribute is missing the "inherit" value. This mistake is not repeated for any of the other elements (layer, para, etc.) of section 4.3. The 'visibility' attribute declaration is also correct in the complete XCF DTD of section 4.4, and is correct as well in the complete external DTD file.

Proposed fix:

In section 4.3.5 'grobject', change

visibility ( on | off) #IMPLIED

to

visibility ( on | off | inherit) #IMPLIED

WG-approved Resolution:

At its 20071011 teleconference, the WebCGM WG approved and endorsed the Proposed fix as described.

- E03: ambiguous applicability of "1024" limit in CLOSED FIGURE (PPF)

Date of this entry: 07 September 2007
(Most recent update: 07 November 2007)

Class: Class 2.

Overview:

In T.15.4 of section 6.4, WebCGM 2.0 limits the number of elements within a CLOSED FIGURE to 1024. The limit is meant to apply to graphical primitive elements, as indicated in discussion by one of the Model Profile authors: "There is no logical reason to include attribute elements. The purpose of the limit is to make predictable the resource requirements of the viewer, and attribute elements have negligible bearing on that."

This qualification is not explicitly stated in the PPF as written (T.15.4 in section 6.4). Therefore, although it would be contrary to the rationale for the limit, it could be read as limiting the total of all kinds of elements. Whereas the ultimate solution would involve clarifying the Model Profile with a CGM:1999 defect correction, the practical companion solution is for the working profiles (WebCGM, ATA, etc) to clarify it, as it seems to have been almost universally assumed.

Proposed fix:

In the row that immediately follows the row containing "T.15.4" in section 6.4, in the WebCGM Profile column (the middle column) change

Other: None.

to

Other: Note that the 1024 element limit applies to the maximum number of graphical primitive elements. Eligible elements of classes other than graphical primitives that are included within the CLOSED FIGURE, e.g., primitive attribute elements, do not count against the 1024 limit.

WG-approved Resolution:

At its 20071011 teleconference, the WebCGM WG approved and endorsed the Proposed fix as described.

- E04: ambiguity on position of radius in degenerate elliptical arc close

Date of this entry: 07 September 2007
(Most recent update: 07 November 2007)

Class: Class 2.

Overview:

T.26.10 in WebCGM 2.0 section 6.15 adopts for WebCGM the treatments of degenerate graphical primitives that are recommended in annex D of CGM:1999. CGM:1999 D.4.5.12 specifies that coincident start ray and end ray in ELLIPTICAL ARC CLOSE should result (among other things) in drawing of a radius. It is implicit, but not explicitly stated, that the radius is drawn along the coincident start-end rays -- this is the only location that fits the rationale behind the choice of fallbacks for such degeneracies. (Ultimately, there should be a CGM:1999 defect correction to put the explicit statement into D.4.5.12.)

Proposed fix:

Clarify in T.26.10 of WebCGM 2.0 section 6.15 that the drawn radius is along the start-end rays. In the row following the line containing "T.26.10", add to the WebCGM Profile column (the middle column) the following:

Note. For degenerate ELLIPTICAL ARC CLOSE, the radius specified in D.4.5.12 is drawn along the coincident start-end rays.

WG-approved Resolution:

At its 20071011 teleconference, the WebCGM WG approved and endorsed the Proposed fix as described.

- E05: wrong case in 'apsId' usage in example 5.1b

Date of this entry: 07 September 2007
(Most recent update: 07 September 2007)

Class: Class 2.

Overview: http://lists.w3.org/Archives/Public/public-webcgm-wg/2007Aug/0021.html

In XCF definition of Chapter 4, all element names in section 4.3, and their associated attributes, are lower case. This includes 'apsid' attribute that occurs on many of the 4.3 elements. In example 5.1b of section 5.3, camel-case is used for 'apsId'. This is incorrect XCF according to section 4.3, and must be fixed.

There are other occurrences of the camel-case 'apsId' usage in Chapter 5. In section 5.7.5 it appears as 'apsId' in a parameter name for a method, which is more or less harmless. In section 5.7.6 the attribute of the object is defined as 'apsId' (READONLY). While this might be bad practice to write it differently than in Chapter 4, in the specific context of these XCF and the DOM definitions, it will not lead to implementation problems in practice. Whereas changing to lower-case would invalidate existing DOM scripts.

The minimal fix is to fix 5.1b, and leave the other occurrences.

Proposed fix:

In example 5.1b of section 5.3, change 'apsId' to 'apsid'.

WG-approved Resolution:

At its 20071011 teleconference, the WebCGM WG approved and endorsed the Proposed fix as described.

- E06: case insensitivity of <param> attribute values

Date of this entry: 07 September 2007
(Most recent update: 07 November 2007)

Class: Class 2.

Overview: http://lists.w3.org/Archives/Public/public-webcgm-wg/2007Aug/0036.html

It is implicit in WebCGM 2.0 section 3.4, but never stated explicitly, that the values of the attributes of the <param> element are case insensitive. See for example the various treatments of 'middle' in the text and examples. This is consistent with the Ch.4 PPF convention of case insensitivity whereever possible in non-graphical text. See, for example, the sub-strings of the METAFILE DESCRIPTION element (T.16.2 of section 6.5) and the font names in the FONT LIST element (T.16.13 of section 6.5). Comparison of WebCGM 2.0 section 3.4 with WebCGM 1.0 section 3.4 also shows additional case-insensitivity assumption.

Proposed fix:

In section 3.4, add to the end of the paragraph that immediately precedes the definition list of <param> definitions, i.e., immediately before the line "onload: <eventHandlerName(evt)>":

The names and the permissible values are case-insensitive, with the single exception of the value of the 'onload' <param> (which identifies the event handler script function that is to be invoked upon the onload event, represented below as "<eventHandlerName(evt)>".

WG-approved Resolution:

At its 20071011 teleconference, the WebCGM WG approved and endorsed the Proposed fix as described.

- E07: typo in LINE TYPE entry in PPF

Date of this entry: 07 September 2007
(Most recent update: 07 November 2007)

Class: Class 2.

Overview:

There is a transcription error in T.20.2 of section 6.9, the LINE TYPE element. In the Model Profile column (the middle column), the "negative values" specification is applicable to [v3] and [v4] metafiles, not just [v3] metafiles. The transcription error was fixed in the Model Profile column (right-hand column) during publication of 2.0, but was overlooked in the WebCGM Profile column (middle column).

Proposed fix:

In the row after the row containing "T.20.2" in section 6.9, in the WebCGM Profile column (the middle column), change

For [v3] metafiles

to

For [v3] and [v4] metafiles

WG-approved Resolution:

At its 20071011 teleconference, the WebCGM WG approved and endorsed the Proposed fix as described.


Rejected proposed errata:

- R01: TBD (revised @@ @@ 2007)

Description:

Tbd

Resolution:

Tbd


Thierry Michel