2011/11/11 Justin Edelson <[email protected]>:
> 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 :)
+1

>
> 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.
Hmm, I'm not a fan of declaring a service just for the sake to provide
meta information :)
But we could use the annotations to just generate meta type info, by
just using the Component annotation with ds=false.

Carsten

>
> 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]
>>
>



-- 
Carsten Ziegeler
[email protected]

Reply via email to