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n140502 nfoWorks nfoNote
ODF 1.2 Change-Tracking Complexity


 0.04 2017-04-10 14:10 -0700


It is natural to ask, "Why is WYSIWYG Change-Tracking so complicated?"   There are two levels to the problem:

  1. The visual presentation manipulations are easy to envision, and it is easy to presume that desired behaviors and presentation are simply a "small matter of programming."  It's no small matter.  Complexity comes from having changes be accurately reversible along with the arrangements that enable presentation of changes in a coherent view to the user, including with the before-and-after forms being visible in some comprehensible form.
  2. Reversible transformations, at the document-format level, are not independent.  That is, seemingly-simple changes have significant interdependencies with other aspects of the document, including material in distant parts of the document.  This leads to great care required to manage the interactions and their proper preservation when the changes are accepted or rejected at some future time.  It is important to identify what those interdependencies are so their treatment is accounted for.

This analysis is anchored in the ODF 1.2 document format for text documents.  Investigation begins with identification of the direct elements identified with change-tracking features in ODF Text documents. 

The next stage identifies the structure of texts in which change-tracking is applied and the corresponding tracked-change data.  There needs to be an appropriate presumption that the tracked changes are manifest for inspection and are reversible, without presumption of agreement between producer and consumer beyond the explicit provisions of ODF 1.2.. 

The presumption of accurate reversibility is an undefined situation that confronts consumers.  It is already known that the tracked-change data is insufficient to provide assurance of perfect reversal in actual practice, because changes are permitted that, as preserved in tracked changes, are not reversible.  A consumer cannot be assured to detect when that is the case and to compensate for it.  That will have to be captured in a way that describes the situation without prescribing it any more than ODF 1.2 does.

Then the insertion, deletion, and format-change operations and how they slice through change-tracked texts are expressed in a form that captures what is allowed and what is unknown about it.

The resulting cases identifying where implementation-behavior of implementations is required.  It can then become implementation-defined how how consumers are resilient in the face of exceptional situations, and defective documents, that arise in conjunction with change-tracking markup provisions.  It also becomes clear how little an implementation can signal, within the provisions of ODF 1.2, concerning what is required for expressed tracked-changes to be reversible.

Detailed requirements for specific approaches to interoperable implementation in ODF Format and in inter-format conversions (including inter-document clip-board-like copy/negotiation/paste) are left for separate resolution, whether by profile agreements, upgrading of the ODF specifications, or other means.   The analysis is intended to be available for reference and hypertext linking from profiles and proposed alternatives.  Cross-reference to such analyses at the detail level remains to be determined.

-- Dennis E. Hamilton
Seattle, Washington

1. Conceptualization

{Ed.Note: To be a top-level guide to the conceptual elements of a reconstruction of the details and the interdependencies involved in the format-level handling of tracked changes.  The cases are identified, not resolved.  In that sense, everything is as implementation-dependent to the degree unspecified for ODF 1.2.  There may be eventual up-linking to RCT provisions.  This further breakdown might not be required, or it could be an Overview that navigates the enclosed material.}

2. Resources Bibliography

{Ed.Note: Either a brief bibliography or an index into chunks of a more-elaborate one.}

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3. Related Material

Hamilton, Dennis E.
ODF 1.2 Change-Tracking Complexity.   nfoWorks nfoNote folio n140502 0.04, July 4, 2014.  Accessed at <>.
Revision History:
0.04 2014-07-04-10:10 Clarify the Deconstruction Process
The Synopsis is extended and refined to reflect the latest thinking of the separation between RCT and this generally-applicable analysis of the state of change-tracking support in the ODF 1.2 specification.
0.03 2014-07-03-12:25 Change Issues Roster to Background
Use as collection of references and material covering the history of change-tracking in ODF.
0.02 2014-07-02-15:39 Add Issues Roster
Changing n140502b title to emphasize analysis
0.01 2014-06-10-17:40 Add Related Material
Sources of supporting and allied material are added.
0.00 2014-05-05-16:30 Cover Page for Initial Material
Serve as placeholder.  Also start a job jar page for recording work items for building more content. 

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created 2014-05-05-16:30 -0700 (pdt) by orcmid
$$Author: Orcmid $
$$Date: 17-04-10 14:10 $
$$Revision: 165 $