On Aug 7, 2006, at 12:05 PM, Michael Victorov wrote:
Currently I implemented big hierarchy of serializers/deserializers to
provide mostly all of query and sync capabilities. Code at
https://svn.objectstyle.org/repos/soc/trunk/cayenne-ropwsdl/.
It would be nice to review and commit this code to the master SVN at
Apache. I know Kevin mentioned that he is busy and can't dedicate
needed time to that. If any other committers can help with this (and
also Eclipse plugin project), please speak up.
I don't have bandwidth for a thorough review of this project, so my
comments are based only on Michael's description.
Questions:
1. It seems like most of Cayenne classes can not be serialized or
deserialized without accessing their private fields through
reflection. I placed "//TODO" at places in cayenne-axis project where
private fields are accessed.
That's ok - serializing private fields is a fairly acceptable
practice (although I'd think that most of them are at least protected).
To avoid cyclic blocking dependences in deserialization process I need
to provide initial deserialized value at the early stage of
deserialization. Most of Cayenne classes constructors need child
objects to be deserialized to invoke. And in many cases these child
objects need parent object to be created before. To make
deserialization work I povided constructors of many objects with fake
values and then replaced these values with deserialized correct ones
(using reflection).
So it works. But it's wrong. Some comments - what can I do with it?
When dealing with Hessian serialization, I usually created a private
noarg constructor. If it is missing for some classes, please submit a
patch via Jira - I will apply it.
2. My web service can work without client business logic classes on
serverside. But I need different .map.xml files on server and client.
On serverside all entities must be assigned to CayenneDataObject class
instead of actual business logic classes.
Maybe I can write an ant task to convert xml files provided by
modeller. Is it ok?
Ideally this needs to be addressed as a patch to Cayenne. Cayenne
should provide this functionality out of the box.
3. Client classes must be subclasses of
org.apache.cayenne.remote.axis.ClientCayenneDataObject.
It copies implementation of CayenneDataObject with some changes:
It uses getObjectContext() instead of getDataContext() in methods
addToManyTarget(), removeToManyTarget(), setToOneTarget(). So these
methods still work when provided context is not DataContext.
It seems like such use of getObjectContext() instead of
getDataContext() can
be implemented in main cayenne distribution. Or am I wrong?
Also there is a method named validateForSave() which will not work
without local DataContext...
I suggest subclassing org.apache.cayenne.PersistentObject - it is
more lightweight and doesn't have all those methods (CayenneContext
supports it already)
4. It would be better to remove .driver.xml file (with db info) from
client side. But I need working local configuration on client side to
map entities to classes and do validateForSave() (etc...). Is there
some crorrect way to make configuration work (maybe partly) without
.driver.xml class?
Per my comment on #2, I hope we can still get the mapping from the
server and avoid this proble all together. Then on the client you can
create a mapping of abstract entity name (e.g. "Artist") to a client
class name (e.g. "my.special.Artist") - this can be a hashmap loaded
from properties or something. Then you can merge it with the
EntityResolver obtained from the server.
Andrus
