How to reset a particular view object alone to it's initial state??

Question

Hi,
My application contains view objects with custom data source implementation. One of my requirement is to reset the particular view object alone to it's initial state. I can't use rollback since it is at Db Transaction level. I searched in forums and finally written the following coding to achieve it. It works fine during sometime but sometimes i am getting the exception oracle.jbo.DeadEntityAccessException: JBO-27101: Attempt to access dead entity in Person, key=oracle.jbo.Key[1 -10 ]
    public void resetPersonViewObject(String voName) {
        Iterator dirtyItr = this.getEntityDef(0).getAllEntityInstancesIterator(this.getDBTransaction());
        while (dirtyItr.hasNext()) {
            Object obj = dirtyItr.next();
            if (obj instanceof EntityImpl) {
                EntityImpl entity = (EntityImpl)obj;
                String state = null;
                byte entityState = entity.getEntityState();
                switch (entityState) {
                case Entity.STATUS_INITIALIZED:
                    state = "Initialized";
                    // Don't do anything
                    break;
                case Entity.STATUS_UNMODIFIED:
                    state = "Un-Modified";
                    // Don't do anything
                case Entity.STATUS_DEAD:
                    state = "Dead";
                    // Don't do anything
                    break;
                case Entity.STATUS_DELETED:
                    state = "Deleted";
                    entity.revert();
                    // entity.refresh(Entity.REFRESH_CONTAINEES);
                    break;
                case Entity.STATUS_MODIFIED:
                    state = "Modified";
                    entity.refresh(Entity.REFRESH_UNDO_CHANGES);
                    break;
                case Entity.STATUS_NEW:
                    state = "New";
                    entity.refresh(Entity.REFRESH_FORGET_NEW_ROWS);
                    entity.refresh(Entity.REFRESH_REMOVE_NEW_ROWS);
                    break;
                System.err.println("State : " + state);
        getDBTransaction().clearEntityCache(getEntityDef(0).getFullName());
        getViewObject().clearCache();
}Questions:
1. How to achieve my requirement? Is there any code correction required?
2. How to reset the row which is actually deleted by the user?
3. The sample code shown above is applicable for all the view object instances which are created from the same entity? What should i do if i want to reset a particular instance of a view object (I may use different instance of same view object at various screens whereas i want to reset only one)
Can anyone help on this??
Thanks in advance.
Raguraman
Edited by: Raguraman on Apr 24, 2011 8:48 PM

Answer 1

Hi,
As per my requirement, i use various instances of same view object in various dynamic tabs only. Since each tab has its own transaction, refreshing an EO of a particular transaction will refresh only the VO instances which comes under that transaction. So it will not cause any issue for my requirement i hope.
Requirement: Need to reset a particular entity driven view object instances.
Tried Schema: Departments table of HR Schema. Tried using the Application Module tester.
Code i use:
    // Client Interface method of DepartmentsViewImpl
    public void resetView() {
        Iterator dirtyItr =
            this.getEntityDef(0).getAllEntityInstancesIterator(this.getDBTransaction());
        while (dirtyItr.hasNext()) {
            Object obj = dirtyItr.next();
            if (obj instanceof EntityImpl) {
                EntityImpl entity = (EntityImpl)obj;
                byte entityState = entity.getEntityState();
                switch (entityState) {
                case Entity.STATUS_UNMODIFIED:
                    break;
                case Entity.STATUS_INITIALIZED:
                    break;
                case Entity.STATUS_DEAD:
                    break;
                case Entity.STATUS_DELETED:
                    entity.refresh(Entity.REFRESH_WITH_DB_FORGET_CHANGES);
                    break;
                case Entity.STATUS_MODIFIED:
                    entity.refresh(Entity.REFRESH_UNDO_CHANGES);
                    break;
                case Entity.STATUS_NEW:
                    entity.refresh(Entity.REFRESH_FORGET_NEW_ROWS);
                    entity.refresh(Entity.REFRESH_REMOVE_NEW_ROWS);
                    break;
        getDBTransaction().clearEntityCache(getEntityDef(0).getFullName());
        getViewObject().clearCache();
Issue i have:
1. Add a blank row (Soon transaction has become dirty). Call the resetView() client interface. It gives me JBO-25303: Cannot clear entity cache model.eo.Departments because it has modified rows
2. Modify any row and then delete the same row. Call the resetView(). It gives me JBO-27101: Attempt to access dead entity in Departments, key=oracle.jbo.Key[10 ]
[NOTE:  Above code works fine when for simple deletion of rows, modification of existing rows, new rows]
Edited by: Raguraman on Apr 24, 2011 8:48 PM