cayenne-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Lon Varscsak <>
Subject Re: Cayenne and Serialization
Date Tue, 26 Feb 2019 17:59:45 GMT
So reviving this topic (which is different than the one I just posted
separately), if I archive the DataContext myself along with the object, all
works as I'd expect (objectContext is not null and I get values back from
the object).  I guess I was just surprised that in the case of a Web
application, where the serialization of an object is outside my knowledge
(like when a framework might archive pages to save on memory) that I would
also have to remember to have a reference to (so it would also serialize)
the DataContext.  It happens that I almost always do, but sometimes one
might fetch some stuff with a context that they don't have a reference to
and would get this issue.

I'm sure there's a good explanation for this.

On Thu, Feb 7, 2019 at 6:17 AM Nikita Timofeev <>

> Hi Lon,
> The behavior you described in field-based objects seems normal
> according to Cayenne own test case (see [1] for master branch and [2]
> for 4.0 branch).
> It should be like this in map-based objects too (i.e. no context and
> no values inside). It is supposed that you attach object to context
> manually after deserialization.
> So unless you had some custom logic in map-based objects case, I
> really don't know what is happening.
> Maybe you can share your test case?
> [1]
> [2]
> On Thu, Feb 7, 2019 at 2:07 AM Lon Varscsak <>
> wrote:
> >
> > Hey all,
> >
> > Recently I switched to 4.1's field based data objects (I've been using
> > 4/4.1 for a while, but using the Map based objects) and I ran into an
> > issue.  It appears that when using this type of object, the
> > de-serialization results in an object that is not usable.  It results in
> a
> > HOLLOW object that returns null for all of its values.  This object is
> in a
> > COMMITTED state to start (no changes), so it really shouldn't be doing
> > anything special with serialization, but something is amiss.
> >
> > To set the stage: So the object is called Site, it's PK is called siteId.
> > I fetch an object, I then serialize that object (normally the web
> framework
> > would choose when to, but I've create some test code to verify this), I
> > then deserialize the object.  Now when I call get*AnyAttribute*() on the
> > deserialized Site object, they all return null and the object is HOLLOW.
> > In the Map based template, the object is still hollow, but all of the
> > properties will return a value.
> >
> > Something else that really surprised me (just because of how long I've
> been
> > working with this code) is that the deserialized object in both cases no
> > longer have an object context.  Not sure how I haven't encountered a
> > problem with that before.
> >
> > Any thoughts?
> >
> > -Lon
> --
> Best regards,
> Nikita Timofeev

  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message