Re: [office-collab] Use Case - H.1 Formula and Number Modification Example - MCT - 1. Draft

[Svante Schubert <svante.schubert@gmail.com>]

On 22.02.2012 01:36, Andreas J. Guelzow wrote:
> On Tue, 2012-02-21 at 15:28 -0700, Svante Schubert wrote:
>> The interesting change occurs within the content.xml: 
>>
>> State A - before:
>> <table:table-row table:style-name="ro1">
>>     <table:table-cell office:value-type="float" office:value="2010">
>>         <text:p>2010</text:p>
>>     </table:table-cell>
>>     <table:table-cell office:value-type="float" office:value="10000">
>>         <text:p>10000</text:p>
>>     </table:table-cell>
>>     <table:table-cell table:formula="of:=0.15*[.B4]"
>> office:value-type="float" office:value="1500">
>>         <text:p>1500</text:p>
>>     </table:table-cell>
>> </table:table-row>
>>
>>
>> State B - after:
>> <table:table-row table:style-name="ro1">
>>     <table:table-cell office:value-type="float" office:value="2010">
>>         <text:p>2010</text:p>
>>     </table:table-cell>
>>     <table:table-cell office:value-type="float" office:value="11000">
>>         <text:p>11000</text:p>
>>     </table:table-cell>
>>     <table:table-cell table:formula="of:=0.2*[.B4]"
>> office:value-type="float" office:value="2200">
>>         <text:p>2200</text:p>
>>     </table:table-cell>
>> </table:table-row>
>>
>> On the first glance it seems the document has changed at five
>> different places. At a closer look - with some ODF back-ground - only
>> two changes are identified, because the following ODF relations create
>> dependencies of changes:
>>         The cell's @office:value attribute (see [1]) is always
>>         reflected by the cell's paragraph content. 
> I would disagree with this formulation. The cell's paragraph content can
> be deduced from the office:value attribute (assuming one knows the
> applicable style, but not vice-versa). 
Fully agree. This is what I meant to say. The paragraph value is deduced
from the office:value.
>>         Changing a cell's formula (@table:formula attribute, see [2])
>>         changes as well the cell's @office:value - if existent - and
>>         the cell's paragraph content
>>         Changing a cell's content (text of child paragraph), which is
>>         referenced by another cell's formula results in general in a
>>         change of the @office:value and the paragraph text of the cell
>>         with the formula.
>>
>> By the above dependencies the XML changes are mapped into basically
>> two state changes, which can be mapped to two operations to be
>> serialized using Merge-Enabled Change Tracking (MCT):
>>
>>
>>      1. The change of cell value [.B4]
>>      2. The change of the formula of cell [.C4] and the resulting cell
>>         value & paragraph text change
> Unfortunately this only suffices as long as the office:value change is a
> deterministic consequence of a formula change. Simple recalculation of a
> document could change values without any accompanying formula changes
> (think of random number generation or other volatile functions such as
> date, time,....)
You are right. Not only the change of a formula, but as well the
recalculation will trigger the described changes.
In addition due to random functions it will never be sufficient to have
an operation indicating the recalculation of formula, but the results
are important.

PS: If you have a complex scenario in the back of your mind, just draft
at and I will try to solve it.
The technique will evolve by usage.

Thanks for your feed-back,  Andreas!
Svante