Well, it doesn't look like cloning an object manually will be all that
difficult.
I am however running into an issue with the 'writePropertyDirectly' method
on CayenneDataObject.
My basic code is below:
Iterator keys = oldObj.getCurrentSnapshot().keySet().iterator();
while(keys.hasNext()) {
String key = (String)keys.next();
newObj.writePropertyDirectly(key, attr.get(key));
}
However the insert statement is all nulls. Unfortunately the writeProperty
which the auto generated classes use has protected status. Am I
misunderstanding what the writePropertyDirectly method does? Is there a way
around this without reflecting over the class to get and execute the methods
that I want?
-----Original Message-----
From: Mike Kienenberger [mailto:mkienen..laska.net]
Sent: Tuesday, March 23, 2004 4:51 PM
To: Bret Gregory
Cc: 'cayenne-use..bjectstyle.org'
Subject: Re: Clone an Object and Create New PK
Bret Gregory <bret.gregor..ccesspointinc.com> wrote:
> I was wondering if there was an easy way to create duplicate objects
> with their relationships while creating new auto_generated primary
> keys.
>
> I have a table with a 1:n relationship to itself.
> So an Object can be related to a bunch of other objects.
>
> I would like to clone the parent object and all of its ancestors
> without having to manually copy all of their different attributes and
relationships.
> Does anyone know of an easy way to do this?
I don't know if there's Cayenne-specific support for cloning objects.
I know that under WebObjects I did this by creating a new data object,
copying the source data object's attributes to the new data object using
generic data object methods, then creating Entity-specific code for
rebuilding relationships.
I used a Map of Maps to track created objects so I could assign the proper
relationships, since all of the objects (many different Entity types) had to
be created before the relationships could be reset.
I can give you some specific WebObject code examples of this if you end up
having to go the same route.
The API for Cayenne should be similar enough for it to be useful.
Copying objects without relationships is pretty trivial, but once you have
to deal with relationships, things get complicated very quickly.
-Mike
This archive was generated by hypermail 2.0.0 : Thu Mar 25 2004 - 12:59:48 EST