r13459 - gnucash/trunk/src/engine - A good bit of notes about how the Transaction Begin/Commit

[Chris Shoemaker]

Author: chris
Date: 2006-03-03 19:10:12 -0500 (Fri, 03 Mar 2006)
New Revision: 13459
Trac: http://svn.gnucash.org/trac/changeset/13459

Modified:
   gnucash/trunk/src/engine/Transaction.c
   gnucash/trunk/src/engine/Transaction.h
Log:
   A good bit of notes about how the Transaction Begin/Commit
   edit-blocks should work, and why. 

   Converts the very important xaccTransCommitEdit function to use the 
   qof_commit_edit_part2() function instead of something that is 90%
   similar.

   Transactions have a Split list that keeps track of Splits during the edit.
   During edits, this list only grows and never shrinks.  Splits that
   have been destroyed or reparented to other transactions remain in
   the list, along with pre-edit Splits and newly added Splits.  Only after a 
   successful commit does the Split list drop reparented or destroyed
   Splits.  A couple out-of-engine users (mainly the register) call
   xaccTransGetSplitList() an work from the Transaction's split list,
   but they expect to be working with only the Splits that would still be in 
   the Transaction if the in-progress edit would be committed.  So, we
   provide the function xaccTransStillHasSplit(t, s) to allow users to query 
   the in-edit state of the Transaction's Split list.

   xaccTransRemoveSplit() and xaccTransInsertSplit() have been replaced by
   xaccSplitSetParent().

   The new xaccTransCommitEdit tries to take a more conservative approach
   to event generation, too.  Instead of generating every possible event for 
   any commit, it should generate only events that indicate a change to an 
   engine object or relation.

   Move some of the financial-constraint-enforcing functions closer to the 
   relevant data-structures. (from Scrub.c)