[jboss-as7-dev] JBoss Modules: can I dynamically add dependency?

[Jason Greene]

There are two solutions to this problem.

1) Switch the interaction to use plugable constructs (common SPI (interfaces & superclasses), dynamically loaded implementation which depends on the common SPI)

2) Dynamically generate a module with an extra resource root to the same jar


On Sep 24, 2012, at 10:29 AM, ssilvert at redhat.com wrote:

> OK.  Thanks.
> 
> This is alright for now because we only have two JSF impls.  But we want
> to allow users to install additional impls.  So it's a little ugly to
> tell them that they have to make another copy of the jsf-injection
> module for each one.
> 
> 
> On 9/24/2012 9:47 AM, David M. Lloyd wrote:
>> On 09/24/2012 07:49 AM, ssilvert at redhat.com wrote:
>>> On 9/24/2012 8:15 AM, David M. Lloyd wrote:
>>>> Unfortunately this premise is flawed from the start: if you had two
>>>> apps, each requiring a different JSF implementation, this idea could
>>>> never work.
>>> I'm not sure what you mean here.  This is already working.
>>>> In any case you cannot change the dependencies of a static module at
>>>> runtime.  Normally when multiple implementations are available you would
>>>> use reflection to instantiate the implementation you need.  If this is
>>>> not possible then you'll need a separate module for each implementation
>>>> type.
>>> That's the problem.  It's not that I need to instantiate something.
>>> Rather, I need to put jsf-injection in a position where the JSF impl
>>> will find my service and instantiate it.   So the way things are now I
>>> have to statically define a new jsf-injection module for each JSF impl.
>>> Those modules are exactly the same except for one dependency declaration.
>> If JSF is instantiating your module via SPI or similar then yes, you 
>> will need to clone your classes for each implementation because you're 
>> statically linking to the Mojarra API (meaning at run time your modules 
>> are no longer exactly the same as classes have different supertypes and 
>> so on).
>> 
>>> If I could programatically define the module then I wouldn't have to
>>> repeat myself.
>>> 
>>> Maybe JBoss Modules was never meant to be used that way?
>> If every Mojarra implementation is statically defined as a module, then 
>> you will have to create separate static modules for each one.  If you're 
>> loading them in from a deployment then you should use the deployers' API 
>> for defining module dependencies to automatically tack on a copy of your 
>> integration classes.
>> 
>> The reason this is so is that in order to have the very fast startup we 
>> have today, the initial module loader runs in a purely static environment.
>> 
>>>> On 09/24/2012 07:06 AM, ssilvert at redhat.com wrote:
>>>>> I have a module defined like this (currently in master with main and
>>>>> slot="1.2):
>>>>> <module xmlns="urn:jboss:module:1.1" name="org.jboss.as.jsf-injection">
>>>>>      <resources>
>>>>>          <resource-root
>>>>> path="jboss-as-jsf-injection-7.2.0.Alpha1-SNAPSHOT.jar"/>
>>>>>      </resources>
>>>>> 
>>>>>      <dependencies>
>>>>>          <module name="com.sun.jsf-impl"/>   <----- this needs to be dynamic
>>>>>          <module name="javax.api"/>
>>>>>          <module name="org.jboss.as.web"/>
>>>>>          <module name="javax.servlet.api"/>
>>>>>      </dependencies>
>>>>> </module>
>>>>> 
>>>>> Inside a DeploymentUnitProcessor, the module above is added to the
>>>>> ModuleSpecification along with the module for the selected JSF
>>>>> implementation.  The problem I have is that the JSF Injection code is
>>>>> the same for any Mojarra implementation.  But to support multiple
>>>>> implementations I need to declare a separate jsf-injection module with a
>>>>> hard-coded dependency on each implementation installed.
>>>>> 
>>>>> If I could create a module dynamically and dynamically add its
>>>>> dependencies then there would be no need to create more and more modules
>>>>> containing the same jsf-injection jar.
>>>>> 
>>>>> I've been looking at the JBoss Modules API and I don't see how to do
>>>>> this.  Is it possible?
>>>>> 
>>>>> Stan
>>>>> _______________________________________________
>>>>> jboss-as7-dev mailing list
>>>>> jboss-as7-dev at lists.jboss.org
>>>>> https://lists.jboss.org/mailman/listinfo/jboss-as7-dev
>>>>> 
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>> 
> 
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