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Re: Accessing .self() in constructor

I think the only time you must use self() is if you want to make sure the
locking mechanism is turned on and the changes get saved.   Other than that if
the operation is read-only it sholdn't matter which one you use.  I only use
self() if a in database call is modifying another in-database object.


Will Uther wrote:

> Um, don't you need to use self() to get a proxy rather than the OzoneObject
> itself?  I didn't even try "this" once I saw self().
>
> I've worked around this now anyway :).
>
> \x/ill         :-}
>
> --On Tue, Dec 28, 1999 7:02 PM -0900 Tim Brown <Tim.Brown@incenter.org>
> wrote:
>
> > Why can;t you just use "this"?
> >
> > William Uther wrote:
> >
> >> Hi,
> >>   I'm implementing a circular doubly-linked list in Ozone.  When a list
> >> element is created I want to initialize the 'prev' and 'next' pointers to
> >> point back to the object itself.
> >>
> >> Now in straight java this would be:
> >>
> >> class elt {
> >>   elt prev, next;
> >>   elt() {
> >>     prev = this;
> >>     next = this;
> >>   }
> >> }
> >>
> >> And, if I understand things correctly, in Ozone this becomes:
> >>
> >> class eltImpl extends OzoneObject implements elt {
> >>   elt prev, next;
> >>   elt() {
> >>     prev = (elt)self();
> >>     next = (elt)self();
> >>   }
> >> }
> >>
> >> The problem is that the self() method accesses something called the state
> >> (line 68 of OzoneObject.java).  That state is not initialized until after
> >> the object is constructed.  (The env object is constructed line 81 of
> >> ObjectSpace.java, but the state isn't created till line 86.)
> >>
> >> Now, I think I can work around this in my code, so the following is just
> >> speculation:
> >>
> >> I was trying to figure out how to fix Ozone to handle this case
> >> correctly. I can see a couple of solutions:
> >>   -Make an 'OzoneConstructor' that is called after creating each object.
> >> This would mean renaming the constructor of most ozone objects.
> >>   -Modify the OzoneObject constructor so that it takes a reference that
> >> allows it to set the state.  This would mean adding a constructor to all
> >> ozone objects, even those that don't explicitly need one.
> >>   - Modify the methods in OzoneObject so that if they are called when
> >>   state is null they work around the problem somehow (yeah, this might
> >> not work).
> >>
> >> Any other suggestions?
> >>
> >> \x/ill        :-}
> >
> > --
> > Tim Brown
> > URL: http://www.incenter.org
> >
> >
> >

--
Tim Brown
URL: http://www.incenter.org