Re: [dali-dev] Dali comments regarding generated artifacts/wizards

[Tom Mutdosch <tommut@xxxxxxxxxxx>]

Hi Neil,

Thanks for the response.  I'll open up some relevant feature requests as you 
mentioned.  A couple follow-ups:

2) Regarding multiple Persistence Units, though not supported in the Dali 
tooling for 1.0, could Dali be made to be more tolerant of this scenario? 
Entity generation could always use whichever connection/schema is set on the 
project as it is now, and perhaps validation could not report errors based on 
schemas if there are multiple persistence units defined in the project and no 
explicit schema annotation on the entity.  I know you can disable the entire JPA 
validator, but that would be less than ideal as you'd lose the benefits of 
validation altogether.  It seems like using entities from multiple schemas and 
connections inside the same project could be a common user scenario.  So while 
the tooling wouldn't have to assist in this, it would be nice to allow them to 
manually set this up and not see validation errors as if they have done 
something that is not allowed by the JPA spec.

That said, though multiple PUs are not likely for Dali 1.0 release, it sounds 
like this is due mainly to implementation complexity and time constraints.  So 
multiple PUs would still be considered for a future release; is this correct?


4) You mentioned there is a "Platform" concept in 1.0.  Is there any where I can 
find more information about this?  Mainly I'm interested if this concept would 
aid in:
a) selecting an appropriate provider from a list of common providers.
b) have a way to set provider-specific properties.  For example, if I select the 
toplink provider and I want to use a driver-managed connection, the appropriate 
provider-based properties would need to be generated into the persistence.xml, 
such as:
<property name="toplink.jdbc.driver" value="com.ibm.db2.jcc.DB2Driver"/>

Thanks,
Tom




Neil Hauge wrote:
> Thanks for your feedback Tom.  Here are some responses for you:
>
>
> Project/Persistence Unit creation
> 1) The request for a schema to be written out to the orm.xml as the 
> default for the persistent unit sounds like a good idea. Please enter an 
> enhancement request for this feature in bugzilla if you could. - 
> https://bugs.eclipse.org/bugs/enter_bug.cgi?product=Dali%20JPA%20Tools
>
> 2) Unfortunately Dali 1.0 will likely not explicitly support multiple 
> persistence units per project. There is a lot of complexity that is 
> introduced with multiple persistence units in a single project having to 
> do with validation and defaulting, among other things. As of now, our 
> 1.0 version will support one persistence.xml per project and one 
> persistence unit per persistence.xml.
>
> 3)  This functionality is in the plan for 1.0.
>
>
> 4) Dali 1.0 will have a "Platform" concept that will deal with this and 
> many other issues regarding vendor specific functionality
>
> Generate Entities
> 1) This is in the plan for Dali 1.0 as well, but you may want to add an 
> enhancement request to express adopter interest in this. Without support 
> for multiple persistence units, this may not make as much sense, but 
> still may be a reasonable thing to do.
>
> Entity Generation Customization
> For these items, I think there are a couple of different ways they could 
> be handled. Ideally, enhancement requests would be filed for these items 
> and the Dali team would evaluate whether or not a given request is 
> suitable for the base code, or whether this is something better left to 
> an extender's code base. If it is a good fit for Dali, a code patch for 
> the functionality would be submitted to the ER and then evaluated for 
> inclusion in the base.
>
> Hope this helps,
>
>
> Neil