BC4J/UIX Multi Entity insert/update

Question

Hi!
Problem
Is it possible to insert simultaneously both master and detail BC4J row with single UIX page? I would like to use standard UIX if possible with minimal java, but examples with java would be also helpful.
Example
This seems to be a very simple situation. Has anybody solved it?
In my case I have one generic Document table and additional attributes tables for different kinds of documents like for instance LicenseDocument. Those tables are connected with Document table with 1 to 0..1 relationship and their foreign key to the Document table is also their primary key.
I like the way that BC4J Tester works and I don't know how to make UIX work the same way.
When I use BC4J Tester it assigns the Document table inserted but not yet committed rows primary key (DBSequence) column temporary negative values and I can insert child records that are associated with it. After commit the Document primary key is fetched from the database sequence and all the foreign keys in other tables get updated accordingly.
When I use UIX I don't get those temporary IDs and so I can't create child records before the master record is committed. This is not good as I can't roll back the whole creation of the LicenceDocument.
References
I started by posting this topic to UIX forum (BC4J Multi Entity insert/update but maybe someone here knows the solution.
Thanks in advance!
Mihkel N�ges
[email protected]

Answer 1

I managed to workaround the issue in UIX by not using DBSequence type but fetching the sequence value in EntityImpl create method (as in Steve Muench's Techiniques demo project http://radio.weblogs.com/0118231/stories/2003/07/11/codeSampleIllustratingVariousBc4jProgrammingTechniques.html ):
DocumentImpl.java:
protected void create(AttributeList attributeList)
     super.create(attributeList);
     // Do this last so we don't waste any sequence numbers unnecessarily
     SequenceImpl seq = new SequenceImpl("DOCUMENT_ID_SEQ",getDBTransaction());
     setId(seq.getSequenceNumber());
For some reason the sequence gets asked twice for every row creation. Thats not a big problem, but in the SequenceImpl javadoc this is discussed and as I understand it should not happen.