Re: [office-collab] How do we count? - September 26, 2012

[Robin LaFontaine <robin.lafontaine@deltaxml.com>]

On 24/09/2012 14:40, Thorsten Behrens wrote:

Andreas J. Guelzow wrote:

On Fri, 2012-09-21 at 15:43 -0600, John Haug wrote:

So each time an arbitrary change is rejected or the document content
is altered (change-tracked or not), the numerical references of
some/all the change tracking markup may be invalidated and must be
recalculated by the application, right?

I can't imagine that any application would likely work directly on the
xml representation.

Right. We're talking about import/export filters here - for those, I
would think absolute or relative references are equivalent in
computational complexity (aka big-O). As a first cut,
implementations could simply maintain integer counters for the
components of interest, updated as the file gets imported /
exported.

Cheers,

John is I think correct in identifying a complexity here. It is not to do with the use of XML representation, it is to do with the fact that a deleted paragraph (say) is part of the counting before it is deleted but is not part of the counting after it has been deleted.

That is fairly straightforward to handle in collaboration when the edits are expected to be executed in order, but not so easy for change tracking where anything can be 'rejected'.

On input the application needs to work out the numerical references not only for the actual document as read in but all its previous states as changes were made. I think this will become clearer when there are some more complex worked examples - it is almost impossible to work out without working code.

For example, in a sequence of 10 edits (where edit 1 is the first and edit 10 is the last), if edit 3 deletes a paragraph it is impossible to know where the paragraph was (i.e. where to put it back if that edit is rejected) without going back through (e.g. rejecting in some virtual environment) edits 10, 9, 8, 7, 6, 5, and 4.

Note: There seems to be a difference between collaboration (which references the components in the document as it was before a change) rather than CT (which references components in the document after the change). I am not sure which way MCT works, I thought it was CT according to the earlier presentations, but the Select Committee had all their examples as collaboration. It would be good to have that clarified.

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