Bug in bc4j?, view links at runtime, multi table relationships, accessor name

Question

The following seems like a bug in the business components framework
to me:
To make things simple, I will use view objects aV, bV, cV,
corresponding rows aR, bR, cR and row iterators aI (not used though),
bI, cI.
I create two view links from aV to bV and from bV to cV at runtime,
with the accessor names "Bs" and "Cs".
ViewLink a2b = createViewLinkBetweenViewObjects(..., "Bs", ...);
ViewLink b2c = createViewLinkBetweenViewObjects(..., "Cs", ...);
First of all this code works perfectly fine:
ViewObject aV = a2b.getSource();
ViewObject bV = a2b.getDestination();
ViewObject cV = b2c.getDestination();
while(aV.hasNext())
Row aR = aV.next();
System.err.println("aR");
while(bV.hasNext())
Row bR=bI.next();
System.err.println(" bR");
while(cV.hasNext())
Row cR=cI.next();
System.err.println(" cR");
Using the accessor name "Bs" at the first level is ok, too:
ViewObject aV = a2b.getSource();
while(aV.hasNext())
Row aR = aV.next();
System.err.println("aR");
RowIterator bI=(RowIterator)aR.getAttribute("Bs");
while(bI.hasNext())
Row bR=bI.next();
System.err.println(" bR");
HOWEVER, USING THE ACCESSOR "Cs" AT THE SECOND LEVEL OF THE MULTITABLE
RELATIONSHIP IN THE FOLLOWING CODE, GIVES ME AN EXCEPTION
oracle.jbo.NoDefException: JBO-25002: Definition Cs of type Attribute
not found. THE SEEMS LEGAL USAGE OF THE ACCESSOR "Cs" TOO ME THOUGH,
THEREFORE MY SUSPICION OF A BUG.
ViewObject aV = a2b.getSource();
while(aV.hasNext())
Row aR = aV.next();
System.err.println("aR");
RowIterator bI=(RowIterator)aR.getAttribute("Bs");
while(bI.hasNext())
Row bR=bI.next();
System.err.println(" bR");
RowIterator cI=(RowIterator)bR.getAttribute("Cs");
while(cI.hasNext())
Row cR=cI.next();
System.err.println(" cR");
(By the way, could make your window for filling in the message a little bit wider,
making it easier to cope with the line breaks).
Feedback is appreciated.
Andreas Reuleaux
Klopotek & Partner
[email protected]
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Answer 1

Your results are as expected per the imlementation. Basically you've established (two) ViewLinks between two sets of two instances of VOs.
Now you try and get an accessor to return a set of details. You need to establish a link between that detail set and it's details to use the accessor on the second detail to get the desired results. Basically you've to establish the chaining between appropriate instances of VOs and not just the outer VOs or VO members of your AM.