[FELIX-4507] [DS] "persistent" factory components

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: scr-1.8.0
• Fix Version/s: scr-2.0.0
• Component/s: Declarative Services (SCR)
• Assignee: David Jencks
• Reporter: David Jencks
• Created: 30/Apr/14 16:44
• Updated: 11/Aug/15 05:09
• Resolved: 06/Aug/14 02:04

Description

The lifecycle constraints of factory components make them generally useless. This introduces a different kind of factory component where:

• the componentFactory service is always registered irrespective of whether any references are available
• the components created by newInstance act like regular components created by config admin factory pids; the component is present whether or not references are available and the instance comes and goes as references come and go. Calling dispose removes the component.
• a modify method is added to the ComponentInstance returned from newInstance. (the ComponentInstance implements a new, extension, interface with the modify method)

There are some consequences, such as ComponentInstance.getInstance() may return null and may not always return the same object.

This behavior can be turned on for a particular component with a "extension" attribute in the component descriptor
xmlns:felix="http://felix.apache.org/xmlns/scr/extensions/v1.0.0"
felix:persistentFactoryComponent="true"