I am now on the user list...
>Generally yes, as JPA mapping is presumably provider-agnostic.
I haven't used Dali (or other JPA tools yet), but one motivation for doing
so would be to gain access to UML round-tripping... where changes in a class
diagram are reflected in the model, and vice versa. For example, Poseidon's
Apollo for Eclipse tool allows UML rendering of Cayenne's classes, but
changes in the UML are not reflected as metadata in the model (e.g. Java
code). I hope JPA tools would solve this.
But note JPA tools likely store all model data in annotations, but Cayenne
does not (e.g. cayenne.xml)... is this a true statement?
I would hope the industry provides vanilla JPA modelling tools, with the
possibilty of provider-specific tool-extensions to add provider-specific
annotations. In this way, the Cayenne community could provide such
extensions to Dali and/or other tools. In theory, a Cayenne tool could then
generate the cayenne.xml file from both JPA and Cayenne annotations (or use
instrumentation to obsolete cayenne.xml?)
Does this make sense? And if so, could Cayenne-specific annotations
replicate cayenne.xml metadata in the future?
I'll jump over to the Dali newsgroup, as well, to ask if any of this makes
sense from their perspective.
Thanks,
Randy
>From: Andrus Adamchik <andru..bjectstyle.org>
>To: use..ayenne.apache.org
>CC: Randy Leonard <randalleleonar..otmail.com>
>Subject: Re: Cayenne Classic vs. Cayenne JPA
>Date: Wed, 7 Mar 2007 12:41:52 +0200
>
>(This thread has been duplicated on the dev list, see Ari's reply [1].
>Also Randy doesn't seem to be a user list subscriber, so I am cc'ying to
>him)
>
>>- Are there Cayenne functionalities available to Classic, but not JPA
>>version?
>
>Both will be using the same stack. The principal difference is the level
>of access to that stack. JPA hides it completely. Cayenne allows stack
>access from Java code. Actually Cayenne JPA will have a non-standard way
>to expose the stack to the apps. Also I hope we'll provide access to most
>"classic" features in a JPA-compliant manner - via provider extensions
>(see below).
>
>>- Could JPA modelling tools (e.g. Eclipse Dali, etc.) be used in place of
>>Cayenne Modeller?
>
>Generally yes, as JPA mapping is presumably provider-agnostic.
>
>One issue with third party tools (I haven't looked at any yet, so that's
>purely my speculation), is that there won't be UI support for
>provider-specific features. E.g. Cayenne provider allows to map a non- JTA
>DataSource, kind of like Cayenne Classic does, same for SQLTemplate and
>SelectQuery. You'll be able to map these extensions via provider
>properties, but you'll have to know the right property names.
>
>Andrus
>
>
>[1] http://objectstyle.org/cayenne/lists/cayenne-devel/2007/03/0022.html
>
>
>On Mar 6, 2007, at 9:35 PM, Randy Leonard wrote:
>
>>I've read some earlier threads on Cayenne 3.0, and have a few questions:
>>
>>- Is Cayenne 3.0 Classic significantly different from Cayenne 2.x?
>>- Could JPA modelling tools (e.g. Eclipse Dali, etc.) be used in place of
>>Cayenne Modeller?
>>- Are there Cayenne functionalities available to Classic, but not JPA
>>version?
>>
>>
>>Also, I posted a thread last July concerning multiple models in one
>>application:
>> http://mail-archives.apache.org/mod_mbox/cayenne-dev/200607.mbox/%
>>3cDE5966B5-0FDE-436A-89E2-CE42A9F3CE2..bjectstyle.org%3e
>>
>>Two questions on this:
>>- Curious if Cayenne 3 would support this?
>>- If not, would the custom solution described still apply to Cayenne 3?
>>
>>Thanks,
>>Randy
>>
>
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