Update of /cvsroot/modeling/ProjectModeling/Modeling
In directory sc8-pr-cvs1:/tmp/cvs-serv6026
Modified Files:
CustomObject.py
Log Message:
Added full documentation for snapshot_raw(), including the special case where a fk value can get out-of-sync
Index: CustomObject.py
===================================================================
RCS file: /cvsroot/modeling/ProjectModeling/Modeling/CustomObject.py,v
retrieving revision 1.16
retrieving revision 1.17
diff -C2 -d -r1.16 -r1.17
*** CustomObject.py 28 Jul 2003 06:20:19 -0000 1.16
--- CustomObject.py 29 Jul 2003 18:42:13 -0000 1.17
***************
*** 296,299 ****
--- 296,331 ----
keys are allAttributesKeys() with their corresponding values.
+ Special care should be taken when examining the values for primary keys
+ and foreign keys:
+
+ - if your object and all its related objects are already saved in the
+ database, you'll get the PK's and FKs' values, as expected (a special
+ case exists where a FK value can get out-of-sync, see below)
+
+ - if your object is inserted in an EditingContext but has not been saved
+ yet, the PK value will be its TemporaryGlobalID, since there is no way
+ to know the value it will get when it is saved,
+
+ - if your object has a to-one relationship to an other object that is
+ inserted in an EditingContext but not saved yet, the FK's value will
+ be that related object's TemporaryGlobalID --for the same reason then
+ above.
+
+ - Last, if the object's entity defines a foreign key involved in a
+ to-many relationship pointing to it but with no inverse (i.e. self's
+ entity has no to-one relationship using this foreign key), the
+ returned value will its value stored in the Database's cache managed
+ by the framework. In other words, this value will be exact after each
+ saveChanges(), and the first time the object is fetched; afterwards,
+ if the object on the other side modifies its relation pointing to
+ 'self' (e.g. removes it), the value will be out-of-sync with the
+ object graph and will remain as-is until the EditingContext saves its
+ changes again.
+
+ Note: this method does not care about PKs or FKs being marked as class
+ properties. Even when they are class properties, it does NOT look at their
+ values, instead the returned values are extracted by examining the objects
+ related to 'self'.
+
Raises ObjectNotRegisteredError if the object itself is not registered in
an EditingContext, or if any of the objects it is in relation w/ is not
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