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https://issues.apache.org/jira/browse/FELIX-6161?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16928232#comment-16928232
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David Jencks commented on FELIX-6161:
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I doubt that will be practical, but I could be wrong.
My recollection (vague, it was a long time ago) is that in the actual usage
causing the problem, there were several references with the same target filter
on the same component, to get the target component and its service property map
separately injected. If we were willing to support this scenario, we could
register one service listener for each target filter used in the bundle and
distribute the event to the several users of the filter. This would be
theoretically slightly worse than what I came up with but satisfy your "create
service on demand" scenario.
Tom, what do you think?
> SCR: Method of resolving references limits Service ListenerHook
> implementations
> -------------------------------------------------------------------------------
>
> Key: FELIX-6161
> URL: https://issues.apache.org/jira/browse/FELIX-6161
> Project: Felix
> Issue Type: Bug
> Components: Declarative Services (SCR)
> Affects Versions: scr-2.1.16
> Reporter: Arnoud Glimmerveen
> Priority: Major
> Attachments: FELIX-6161.patch
>
>
> When experimenting with creating a Service ListenerHook to realise a
> [providing a service on demand
> pattern|https://osgi.org/specification/osgi.core/7.0.0/framework.servicehooks.html#d0e45721],
> I noticed that references from components managed by Felix SCR were not
> showing up as expected: When a reference declares a target filter, that
> target filter is not included in the ListenerInfo provided to the
> ListenerHook. As a consequence the ListenerHook is unable to create a
> matching service.
> Source of the observed behaviour is how SCR tracks references, specifically
> that it opens a ServiceListener for just the className and performs the
> matching of the target filter inside the ServiceListener. This approach
> unfortunately hides the target filter from the Service ListenerHook and thus
> the Service ListenerHook will have insufficient information to create a
> matching service.
> Also look at the discussion on the dev mailing list:
> [https://www.mail-archive.com/[email protected]/msg48657.html]
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