Andrey,
This is a correct assessment of the situation: (1) setting persistence
state manually is very likely to confuse Cayenne and (2) transient
objects can't have relationships. Another way around it is to create
NEW objects, and delete them before commit:
MyObject o = context.newObject(MyObject.class);
...
for(Object o : context.newObjects()) {
if(somecondition) {
context.deleteObject((Persistent) o);
}
}
context.commitChanges();
Andrus
On Mar 1, 2008, at 11:13 AM, Razumovsky Andrey wrote:
Hi Adrian,
If i understood your message right, you're manually changing
objects' state to COMMITED. Well, i too think this is not a good idea.
What would i do in this cause is to make those still non-existing in
DB objects using default constructor, so that they would bу
TRANSIENT. After that (i think this should be done before calling
'commitChanges', if you don't want to mess with listeners) you
should register user-modified objects with Cayenne using
'context.registerNewObject()'. The objects should be registered only
if they are TRANSIENT and your-business-logic-modified. Once you do
that, their state will change to NEW and they will normally persist.
Those objects which are already in DB will normally work since they
are COMMITED or MODIFIED.
Still, if those objects have relationships you use, this would lead
to exceptions during commit, since there is a problem in setting
existent objects in relations for transient objects. About this i
would write to list in my next question. However, sutuation will be
even worse if you have falsely-commited objects, as you suggest.
Hope this helps,
Andrey
AW>
AW> Hello list
AW>
AW> I have some kind of exotic question concerning state of
DataObjects. In a
AW> scenario I would like to create new DataObjects but keep them in
a state
AW> so that they only get committed if the user actively changes
some default
AW> value.
AW>
AW> Look at it like some lazy persist functionality. Let's say I
have a
AW> reporting application (which I have not :) ) where I display a
matrix to
AW> the user. X-axis are the days, y-axis are the projects. In every
field in
AW> the matrix the user could write the hours he worked on the said
project on
AW> the specific day. Which means I need to create DataObjects for
all fields
AW> in the matrix so that the databinding works and the user can
enter values
AW> into all of the fields. But I only want to persist those records
which
AW> actually contain a value.
AW>
AW> I thought I could do so creating new DataObjects, setting
default values
AW> and then immediately changing the state of the new DataObjects to
AW> committed. While this generally works (DataObject changes to
modified
AW> once the user enters a value), the persist process of Cayenne is
not
AW> amused since it thinks it should update a record in the database
which
AW> does not already exist.
AW>
AW> So my question. Would there be another possible solution to my
problem?
AW>
AW> Cheers,
AW> Adrian
AW>
