Continuum Model and Modello

[Rahul Thakur <ra...@gmail.com>]

I have been wanting to pop this questions for sometime now.

For generation/maintenance of continuum-model:

a) Why are we using Modello? More specifically what does it buy us? I
know the model is expressed as xml and separate from Java sources,
but I don't see a benefit of having it in XML as opposed to
annotations in java sources.

b) Since 1.1 is in final stages, also wanted to see what other think
about brainstorming ideas for the next Continuum release on wiki. But
this might be a candidate for a separate thread.

Thoughts?

Thanks,

Rahul

Re: Continuum Model and Modello

[Brett Porter <br...@apache.org>]

On 21/09/2007, at 5:31 PM, Emmanuel Venisse wrote:

>
>
> Rahul Thakur a écrit :
>> I have been wanting to pop this questions for sometime now.
>> For generation/maintenance of continuum-model:
>> a) Why are we using Modello? More specifically what does it buy us? I
>> know the model is expressed as xml and separate from Java sources,
>> but I don't see a benefit of having it in XML as opposed to
>> annotations in java sources.
>
> modello file generate for use all model POJOs and the jpox metadata  
> file. With it, we can define old fields that doesn't exist in the  
> nex version and the migration tool use the model to do the db  
> conversion. I don't think we can all of that with annotations.

The DB conversion is less than ideal though. I think the tools that  
OpenJPA already provide for doing such things are superior (from the  
brief look I've had).

I'm thinking the model conversion is a bit of a "seemed like a good  
idea at the time" thing that I did... I'd be happier with coding it  
up by hand now and making the store simpler. In making the store  
simpler, and carefully mapping to tables, I think we can avoid the  
need for conversion anyway by trying to only make additions.

I'd be willing to experiment with alternatives - perhaps it would be  
best to do this piece by piece though, rather than one big conversion  
(as the impl. currently leaks out all over - we need to better  
isolate the lazy loading and fetching of data through the actions  
before safely extracting pieces).

Cheers,
Brett

--
Brett Porter - brett@apache.org
Blog: http://www.devzuz.org/blogs/bporter/

Re: Continuum Model and Modello

[Emmanuel Venisse <em...@venisse.net>]

Rahul Thakur a écrit :
> I have been wanting to pop this questions for sometime now.
> 
> For generation/maintenance of continuum-model:
> 
> a) Why are we using Modello? More specifically what does it buy us? I
> know the model is expressed as xml and separate from Java sources,
> but I don't see a benefit of having it in XML as opposed to
> annotations in java sources.

modello file generate for use all model POJOs and the jpox metadata file. With it, we can define old fields that doesn't exist in the nex version and the migration tool use the model to do the db 
conversion. I don't think we can all of that with annotations.

> 
> b) Since 1.1 is in final stages, also wanted to see what other think
> about brainstorming ideas for the next Continuum release on wiki. But
> this might be a candidate for a separate thread.

Yes, it's a separate thread ;)

Emmanuel
> 
> Thoughts?
> 
> Thanks,
> 
> Rahul
> 
>