On 11/24/10 12:01 PM, Guillaume Nodet wrote:
> On Wed, Nov 24, 2010 at 17:45, Justin Edelson <justinedel...@gmail.com> wrote:
>> On 11/24/10 11:28 AM, John Platts wrote:
>>>
>>> I actually want to address issues with Felix and the OSGi specification 
>>> that are not specific to the Spring Framework, Spring DM, or Eclipse Gemini.
>>
>> That's fine. But what you are suggesting IMHO is to break modularity and
>> so whether this is an "issue" in the OSGi spec is *highly* debatable.
>>
>>>
>>> One of the real issues that I want to address is to be able to import 
>>> bundles containing certain packages without having to list all of the 
>>> packages exported by that bundle and without having to know the symbolic 
>>> name of the bundle.
>>
>> So... you want to be able to have:
>>
>> Bundle-Symbolic-Name: com.test.bundle1
>> Export-Package: foo,bar
>>
>> and
>>
>> Bundle-Symbolic-Name: com.test.bundle2
>> Import-Package foo
>>
>> And have com.test.bundle2 *also* import package bar just because foo and
>> bar are both exported by com.test.bundle1?
>>
>>
>>> This feature is useful because:
>>> - It eliminates the need to do a dynamic import of the needed packages
>> Dynamic imports are not a general purpose feature. They should only be
>> used in specific cases.
>>
>>> - It allows entire bundles to be imported without having to know the 
>>> symbolic names of the bundles
>>> - It does not require the user to know all of the packages exported by a 
>>> bundle
>> What's the use case for importing all of the packages a particular
>> bundle exports without knowing either the symbolic name of the bundle or
>> the list of packages?
> 
> Maybe I'm wrong, but my first impression is that John is hitting the
> same problems I had with Spring-DM over the past years (see
> http://gnodet.blogspot.com/2010/03/spring-dm-aries-blueprint-and-custom.html
> for more informations).
> One of those problem is that when using a spring custom namespace, the
> namespace does not contribute to the classloader for the blueprint
> application, hence all classes have to come from the bundle itself
> while they are not referenced directly, but indirectly through the
> custom namespace.  That's a design problem in the way spring-dm has
> been built imho.
> I have actually hit this problem and fixed that in Aries Blueprint
> along with the other Spring-DM problems I mentionned in my blog.

This is a legitimate problem, but I don't see how John's proposed
resolution helps this. It isn't necessarily the case that if you use a
custom namespace, you will be importing a package from the bundle which
defines that namespace.

Justin


> 
> If John is not referring to those problems, I'd be happy to get back
> to the real problems, but that's really why I asked for the real use
> cases.
> 
>>
>> Justin
>>
>>
>>>
>>> ----------------------------------------
>>>> Date: Wed, 24 Nov 2010 17:02:06 +0100
>>>> Subject: Re: Issues that need to be addressed in Apache Felix and the OSGi 
>>>> specification
>>>> From: gno...@gmail.com
>>>> To: users@felix.apache.org
>>>>
>>>> On Wed, Nov 24, 2010 at 16:51, John Platts  wrote:
>>>>>
>>>>> I have been running into several problems when developing web application 
>>>>> bundles that utilize the Spring Framework. The problems that I have been 
>>>>> running into are:
>>>>> - The Spring Framework needs to access META-INF/spring.handlers and 
>>>>> META-INF/spring.schemas files in JARs that have these files
>>>>> - The Spring Framework needs access to packages that are not in the 
>>>>> Import-Package header of web application bundles that utilize the Spring 
>>>>> Framework
>>>>>
>>>>
>>>> I agree those are real issues with Spring-DM. But that's not really
>>>> the place for such discussions.
>>>> FWIW, you should give Aries Blueprint a try, as all those problems
>>>> have been solved in it.
>>>>
>>>>> The issues that really need to be addressed in both Apache Felix and the 
>>>>> OSGi specification are:
>>>>> - The ability to require bundles by specifying packages that they export 
>>>>> instead of by specifying the symbolic names of the bundles.
>>>>> - The ability to make META-INF and its subdirectories visible to class 
>>>>> loaders of bundles that meet at least one of the following criteria:
>>>>>  - Requires a bundle
>>>>>  - Imports all of the packages exported by the bundle (by requiring 
>>>>> bundle(s), importing package(s), and/or dynamically importing package(s)) 
>>>>> plus has a DynamicImport-Package header that includes META-INF and its 
>>>>> subdirectories
>>>>>
>>>>> Addressing the issues above will make it easier to use OSGi bundles from 
>>>>> Web Application Bundles without having to rely on workarounds.
>>>>
>>>> What are you underlying problem ? Maybe they already have some
>>>> solutions. For the first one, this is an OSGi good practice and is
>>>> done widely, so not sure what your issue is. The second one might be
>>>> related to various issues which i'm quite sure have been fixed in
>>>> various ways (having solved some myself).
>>>>
>>>>>
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>>>>>
>>>>>
>>>>
>>>>
>>>>
>>>> --
>>>> Cheers,
>>>> Guillaume Nodet
>>>> ------------------------
>>>> Blog: http://gnodet.blogspot.com/
>>>> ------------------------
>>>> Open Source SOA
>>>> http://fusesource.com
>>>>
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>>>
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>>
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> 
> 
> 


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