We already support the ranking attribute for all service provider declarations. If one provider is expected, the highest one will be used.
Raymond Feng Sent from my iPhone On Dec 9, 2011, at 7:29 AM, Greg Dritschler <[email protected]> wrote: > I'm trying to replace some of Tuscany's service provider files, or in some > cases remove them. I've been struggling with this for a while and thought > I'd toss it out for discussion. Here are examples. > > 1) I want to replace the RequestContextFactory provider. Tuscany finds a > provider file using ServiceDiscoverer.getServiceDeclaration(). As far as I > can tell, when there are multiple provider files, both > EquinoxServiceDiscoverer and ContextClassLoaderServiceDiscoverer pick the > first one found and there's no way to control which one that will be. I > think there needs to be some way to control order. Perhaps the service > declaration should have a weight attribute and getServiceDeclaration() should > pick the one with the highest weight. > > 2) I want to replace an implementation type in one of Tuscany's definitions > file. Tuscany finds Definitions providers using > ServiceDiscoverer.getServiceDeclarations(). Again, there's no way to control > order, so here too a weight attribute might be useful. (PullTransformer > already uses a "weight" attribute for a different purpose so it might have to > be called something else.) The other problem is that Tuscany issues a > warning when there are duplicate definitions. I think there would need to be > some way to suppress that but I'm not sure how. I wouldn't want to lose the > warning altogether because in some cases it might be useful. Also I wouldn't > want application definitions to be able to replace system definitions, which > could happen if we're not careful about this. > > 3) I want to eliminate certain Tuscany policy providers, for example > JaasAuthenticationPolicyProviderFactory and > JMSTokenAuthenticationPolicyProviderFactory, either because I have > alternative providers or I don't want to support the function. However these > providers are bundled with other classes I do need. I think in this case the > simplest thing to do is to separate the policy functionality into another > Tuscany bundle. > > Greg
