Question regarding SymbolSources

[Liebig, Stefan]

While using my own symbol source implementations, I figured out
that it is not possible to do somthing like this:

 

 <service-point id="SymbolSourceTest" interface="symbolsource.StringHolder">
  <invoke-factory>
   <construct class="symbolsource.StringHolder">
    <string>${A}</string>
   </construct>
  </invoke-factory>
 </service-point>

 

 <contribution configuration-id="hivemind.ApplicationDefaults">
  <default symbol="A" value="${B} and more"/>
 </contribution>

 

 <contribution configuration-id="hivemind.ApplicationDefaults">
  <default symbol="B" value="C"/>
 </contribution>

 

There is a chain of links (no cycle): ${A} -> ${B} -> C 
 
Accessing the SymbolSourecTest service results in an:
....
Caused by: org.apache.hivemind.ApplicationRuntimeException: A recursive call to construct configuration hivemind.ApplicationDefaults has occured.  This indicates a cycle between one or more configurations or services.
 at org.apache.hivemind.impl.ConfigurationPointImpl.constructElements(ConfigurationPointImpl.java:180)
 at org.apache.hivemind.impl.ElementsInnerProxyList.inner(ElementsInnerProxyList.java:46)
 at org.apache.hivemind.impl.ElementsInnerProxyList.size(ElementsInnerProxyList.java:62)
 at org.apache.hivemind.impl.ElementsProxyList.size(ElementsProxyList.java:60)
 at org.apache.hivemind.service.impl.DefaultsSymbolSource.initializeService(DefaultsSymbolSource.java:42)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
 at java.lang.reflect.Method.invoke(Method.java:585)
 at org.apache.hivemind.service.impl.BuilderFactoryLogic.findAndInvokeInitializerMethod(BuilderFactoryLogic.java:275)
 at org.apache.hivemind.service.impl.BuilderFactoryLogic.invokeInitializer(BuilderFactoryLogic.java:249)
 ... 104 more

 

However, if you use another SymbolSource which resolves the ${B} from another
contribution than it works, because two different SymbolSource-Services are used.

 

Is it possible to change construction of symbol sources such that no creation cycles occur?

 

Stefan