Providing a "minimal viable product" type of implementation of this as a starting point for users to customize or copy would probably be helpful.
On Fri, Oct 11, 2019 at 9:35 AM Andrus Adamchik <and...@objectstyle.org> wrote: > So you'd need to consume GraphDiff, you need to implement a custom > GraphChangeHandler, and then do "diff.apply(myChangeHandler)" to aggregate > / filter the changes you care about. All the references to "nodeId" in > GraphChangeHandler can be cast to ObjectId, so you can tie it back to the > actual objects. So while it is not user-friendly, I think you can turn it > to useful info in a fairly straightforward manner. > > Andrus > > > > On Oct 11, 2019, at 10:24 AM, John Huss <johnth...@gmail.com> wrote: > > > > I haven't worked with the GraphDiff API much, but it's not super easy to > > turn a GraphDiff into something immediately useful. > > > > When I've needed things like this I've usually constructed a > > List<Map<String, Object>> with a row for each changed object and a map > with > > attribute/relationship key to the new value. Looking at > > NodePropertyChangeOperation - it has the key and the old and new value, > but > > the API doesn't have any way of extracting that information that I see. > > > > Most likely I just don't understand how to use this correctly, but I'm > > guessing I wouldn't be the only one. > > > > On Fri, Oct 11, 2019 at 5:36 AM Andrus Adamchik <and...@objectstyle.org> > > wrote: > > > >> Was just answering Cayenne change tracking question on StackOverlow [1], > >> and realized that the only user-friendly API that allows to check for > >> individual changes is "cayenne-commitlog" that only works during commit. > >> All the pre-commit APIs are internal and require lots of hoop jumping. I > >> think we can address that on the cheap in 4.2 by defining a method like > >> this in GraphManager.java: > >> > >> GraphDiff getChanges(); > >> > >> We already have such method implemented in ObjectStore, so there's > really > >> no effort and an immediate benefit. Or take it a step further and > >> additionally implement filtering changes per object: > >> > >> GraphDiff getChanges(Persistent) > >> > >> Thoughts? > >> > >> Andrus > >> > >> [1] > >> > https://stackoverflow.com/questions/58318730/what-is-the-current-best-method-of-getting-the-changes-to-an-object-hierarchy-in > >
