A configuration printer is certainly an option, but I think the devs I've see run into this problem would be better served by something more interactive. So let's say both :)
I'm not opposed to a metadata file, but the reason I prefer the service property method to a file in META-INF is that we can reuse the service properties from AdapterFactory implementations. The Web Console doesn't need to care whether the metadata is provided by a metadata provider service or an AdapterFactory service (or some other arbitrary service). See https://gist.github.com/1359911 for an example of the Web Console plugin I built as a POC. Justin On Fri, Nov 11, 2011 at 6:08 PM, Carsten Ziegeler <[email protected]> wrote: > Great idea and I'm definitely +1 on such a web console plugin. Not > sure if this is a web console plugin or a configuration status > renderer (we need the last one as well). > > I think instead of defining the additional metadata through the java > annotations with additional classes like the > JcrNodeResourceAdapterMeta in your example, what about having a meta > data file in META-INF of the bundle instead. I know its separate from > the java code though. > > Regards > Carsten > > 2011/11/11 Justin Edelson <[email protected]>: >> Working with new Sling developers, I find that one of the concepts >> they have trouble with is in the area of Adapters and that it is hard >> to find out what objects are adaptable to which classes. Although it >> is possible to document this (see for example >> http://dev.day.com/docs/en/cq/current/developing/sling-adapters.html), >> because new Adapters can be dynamically added (or removed) through >> OSGi services, any documentation is potentially incomplete. >> >> What I would like to do is create a new Web Console plugin which >> displays the list of available adaptation pairs. I'm still thinking >> about the UI, but you could imagine that a first version would be a >> select list on the left listing the adaptable classes and a list on >> the right of the possible adapters for the selected adaptable. >> >> For implementations of AdapterFactory, the necessary metadata already >> exists in the service registry, but for cases where a class implements >> its own adapters, this metadata needs to be added. >> >> In order to do this, I propose the following: >> 1) The creation of such a Web Console plugin (obviously). >> 2) The creation of new OSGi Services for classes which implement their >> own adaptations. For example: >> @Component >> @Service(value=Object.class) >> @Properties({ >> @Property(name="adaptables", >> value="org.apache.sling.api.resource.Resource"), >> @Property(name="adapters", value={ >> "javax.jcr.Node", >> "javax.jcr.Item", >> "java.io.InputStream", >> "java.net.URL", >> "java.util.Map", >> "org.apache.sling.api.resource.ValueMap" >> }) >> }) >> public class JcrNodeResourceAdapterMeta { } >> >> 3) The establishment of a new service property, named >> adapter.condition, which optionally indicates the conditions under >> which an adaptation can be made. For example, in the case above: >> @Property(name="adapter.condition", value="If the resource is a >> JcrNodeResource") >> >> The Web Console plugin would need to note that potentially not all >> adapters are listed, but I believe that if we add the metadata for all >> the adapters in Sling, that will set a good precedent for downstream >> projects to follow. If we want, we could also add a note which says >> "If there's an adapter not listed here, please file an issue with the >> adapter provider." :) >> >> Adding this metadata is not a trivial amount of effort, but it also >> something I feel will pay dividends down the road. >> >> WDYT? >> >> Justin >> > > > > -- > Carsten Ziegeler > [email protected] >
