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>
>
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