2.0.4: child DataContext & localObject

From: Marc A. Donis (mad..unbox.com)
Date: Thu Nov 01 2007 - 17:42:41 EDT

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    Hi,

    I am seeing a strange interaction between child DataContexts and
    localObject. If I set a to-one relationship from an object residing in a
    child context to another object which lives in that context's parent, I see:

    org.apache.cayenne.CayenneRuntimeException: [v.2.0.4 October 12 2007] Cannot
    set object as destination of relationship abuseStatus because it is in a
    different DataContext

    So I do:

    ..verride
     public void setToOneTarget(String relationshipName, DataObject value,
    boolean setReverse) {
      if (value != null && value.getDataContext() != this.getDataContext() &&
    value.getDataContext() != this.getDataContext()) {
       DataContext dc = getDataContext();
       value = (DataObject) dc.localObject(value.getObjectId(), null);
      }
      super.setToOneTarget(relationshipName, value, setReverse);
     }

    in the child context object's class, which works fine (but seems like it
    should not be necessary?).

    But what I really want is:

      DataContext refDataContext = DataContext.createDataContext();
      CayenneDataObject ref = ...// get reference from refDataContext
      DataContext userDataContext =
    DataContext.createDataContext().createChildDataContext();
      CayenneDataObject obj =
    userDataContext.createAndRegisterNewObject(MasterObject.class);
      obj.setRef(ref);

    In other words, the obj's context (the child context) is not a child of the
    referenced object's context.
    In combination with the first bit of code, I now get:

     org.apache.cayenne.validation.ValidationException: [v.2.0.4 October 12
    2007] Validation has failed.
    Validation failure for MasterObject.ref: "ref" is required.

    because all the to-one relationship values set in this way are reset to null
    during userDataContext.commitChanges()!

    The stack looks like this:

    MasterObject.setToOneTarget(UnAmourDataObject.java:11) *** value == null
    in this call
    org.apache.cayenne.access.ChildDiffLoader.arcCreated(ChildDiffLoader.java:120)
    org.apache.cayenne.access.ObjectDiff$ArcOperation.apply(ObjectDiff.java:428)
    org.apache.cayenne.graph.CompoundDiff.apply(CompoundDiff.java:97)
    org.apache.cayenne.access.ObjectStoreGraphDiff.apply(ObjectStoreGraphDiff.java:136)
    org.apache.cayenne.access.DataContext.onContextFlush(DataContext.java:1188)
    org.apache.cayenne.access.DataContext.onSync(DataContext.java:1167)
    org.apache.cayenne.access.DataContext.flushToParent(DataContext.java:1234)
    org.apache.cayenne.access.DataContext.commitChanges(DataContext.java:1138)

    Thoughts? Comments? Suggestions?

    Thanks,
    Marc

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