[hibernate-dev] Building a SessionFactory

[Steve Ebersole]

I do not disagree, especially about the clutter.  I had two related 
concerns with that this approach though:
1) minor, but this thing is then no longer just collecting the sources 
of metadata which is what a MetadataSources is.
2) this is no longer a "directed API" at all.  What do I mean by that? 
Well:

MetadataSources sources = new MetadataSources(...);
sources.setNamingStrategy( strategy1 );
sources.addResource( "some/resource.xml" );
sources.setNamingStrategy( strategy2 );
sources.addResource( "some/resource2.xml" );

We are not "directing" the users to the correct usage of the API by the 
design of the API itself.


Here is another option:
MetadataSources sources = new MetadataSources(...)
     ...
     .getMetadataBuilder()
     .setNamingStrategy( ... )
     .buildMetadata();

Now the naming strategy is associated with this "metadata builder" which 
is more semantically correct.  But this is a bit verbose for today since 
I can only think of naming strategy as falling into this bucket.


On 04/22/2011 03:37 AM, Emmanuel Bernard wrote:
> My preference would go to a MetadataSources#setMetadata(NamingStrategy)
>
> My fear is that more functions could be needed overtime and make the constructor or the buildMetadata signature cluttered and less readable.
>
>
> On 21 avr. 2011, at 15:08, Steve Ebersole wrote:
>
>> NamingStrategy is not a service.  It is solely a function of building the metadata.
>>
>> Currently, again, I have this set up via ctor param passing:
>>
>> new MetadataSources( reg, new MyNamingStrategy() )
>>
>> Really its not logically part of the source, its needed during the transition from source->metadata, so an alternative I have been contemplating is:
>>
>> new MetadataSources( reg ).buildMetadata( new MyNamingStrategy() )
>>
>> I am open to other suggestions.  I really am trying to keep in mind the scope in which stuff is needed/useful/valid.
>>
>>
>> On 04/21/2011 03:11 AM, Emmanuel Bernard wrote:
>>>
>>> On 21 avr. 2011, at 05:43, Steve Ebersole wrote:
>>>
>>>> I think this new API for creating a SessionFactory is starting to firm
>>>> up, so I wanted to put out another call for feedback before we get too
>>>> close to Alpha3.  So at a high level there are 2 pieces of information
>>>> needed to build the SessionFactory: the ServiceRegistry and the Metadata.
>>>>
>>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>>
>>>> The ServiceRegistry is built through a ServiceRegistryBuilder (this is a
>>>> slight recent change)
>>>>
>>>> Map config = ...;
>>>> ServiceRegistry serviceRegistry = new ServiceRegistryBuilder( config )
>>>>          ...
>>>>          .buildServiceRegistry();
>>>>
>>>> The "..." allows you to add service instances and service initiators.
>>>> Currently any (map of) configuration values is passed in the
>>>> constructor.  I can be convinced to allow adding/setting of config
>>>> values as well, if everyone has a preference for that approach:
>>>>
>>>> Map config = ...;
>>>> ServiceRegistry serviceRegistry = new ServiceRegistryBuilder()
>>>>          .setConfigurationData( config )
>>>>          .setOption( Environment.SHOW_SQL,
>>>> true )
>>>>          ...
>>>>          .buildServiceRegistry();
>>>>
>>>> Not sure the best method names there, to be honest which is why I opted
>>>> for passing them to ctor.
>>>
>>> Is that a Map<Object,Object>   or something a bit more refined?
>>>
>>> Regardless of the map being passed to the ctor, I'd think you need to ability to set additional options (like you setOptions)
>>>
>>> Alternative names:
>>> option: setting
>>>
>>> Not really related but, now that Configuration is gone, we lose some of the type safety (like cfg.setNamingStrategy(new MyNamingStrategy() ), or am I forgetting something in how the service registry works?
>>>
>>>>
>>>>
>>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>>
>>>> Metadata is built through a MetadataSources which represents the sources
>>>> of metadata information.
>>>>
>>>> MetadataSources metadataSources = new MetadataSources( serviceRegistry )
>>>>          .addResource( "some.hbm.xml" )
>>>>          .addAnnotatedClass( SomeEntity.class );
>>>> Metadata metadata = metadataSources.buildMetadata();
>>>>
>>>>
>>>>
>>>> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>>>>
>>>> The Metadata is then used to obtain a SessionFactory.
>>>>
>>>> SessionFactory sf = metadata.buildSessionFactory();
>>>>
>>>>
>>>> Metadata represents the "configuration time" mapping information.  As of
>>>> now we will allow users to manipulate and otherwise access this
>>>> information, hence the seeming "intermediate step".  These all work with
>>>> chaining:
>>>>
>>>> SessionFactory sf = new MetadataSources( serviceRegistry )
>>>>          .addResource( "some.hbm.xml" )
>>>>          .addAnnotatedClass( SomeEntity.class )
>>>>          .buildMetadata()
>>>>          .buildSessionFactory();
>>>>
>>>
>>> I guess you could have a buildMetadataSources() hosted on ServiceRegistry if you want people to use chaining methods all the way.
>>
>> --
>> Steve Ebersole<steve at hibernate.org>
>> http://hibernate.org
>

-- 
Steve Ebersole <steve at hibernate.org>
http://hibernate.org