I quickly tried to implement a POC, but due to type erasure the interface is not as simple as just putting RequireAdapter<Foo>.class I found the following reference: http://gafter.blogspot.de/2006/12/super-type-tokens.html and tried to implement something like that but could not get it to work in a simple fashion. @Bertrand: Do you have an example in mind on how to get the wrapped type of RequireAdapter? Thanks, Konrad
On 01 Jul 2014, at 12:09, Konrad Windszus <konra...@gmx.de> wrote: > > On 01 Jul 2014, at 12:05, Stefan Seifert <sseif...@pro-vision.de> wrote: > >>> Foo f = someObject.adaptTo(RequireAdapter<Foo>.class)); >> >> this would still require an "unwrapping" of the object out of the >> RequireAdapter<Foo> instance. > In my regard there is an instanceof RequireAdapter check within the > AdapterManagerImpl which would in that case just pass/throw exceptions. So no > need to unwrap anything for the client. > The only questions is how to get the generic type at runtime (within the > AdapterManagerImpl), but there are solutions to that as well: > http://stackoverflow.com/questions/3403909/get-generic-type-of-class-at-runtime > > >> >>> Foo f = someObject.adaptTo(RequireAdapter.for(Foo.class)); >> >> this looks interesting, and does not need unwrapping if the return value is >> the input class. >> i assume it could be implemented using a ThreadLocal or similar as well? >> >> stefan >> >> >>> -----Original Message----- >>> From: Konrad Windszus [mailto:konra...@gmx.de] >>> Sent: Tuesday, July 01, 2014 11:58 AM >>> To: dev@sling.apache.org >>> Cc: Bertrand Delacretaz >>> Subject: Re: adaptTo and results .... >>> >>> I like that approach. It is backwards-compatible and allows the developers >>> to >>> decide whether they want to check for null or to rely on exceptions. >>> The AdapterManagerImpl indeed would need to deal with such a parametrisation >>> and in addition the javadocs would need to be adjusted to make it clear that >>> AdapterFactories may throw RuntimeExceptions. >>> Those exceptions should be caught by the AdapterManagerImpl when the >>> RequireAdapter was not requested and in the other case just passed along. >>> >>> >>> On 01 Jul 2014, at 09:44, Bertrand Delacretaz <bdelacre...@apache.org> >>> wrote: >>> >>>> On Tue, Jul 1, 2014 at 9:41 AM, Bertrand Delacretaz >>>> <bdelacre...@apache.org> wrote: >>>>> ...how about this: >>>>> >>>>> Foo f = someObject.adaptTo(RequireAdapter.for(Foo.class)); >>>> >>>> Actually, rereading SLING-3714, this can be made simpler with generics >>>> >>>> Foo f = someObject.adaptTo(RequireAdapter<Foo>.class)); >>>> >>>> where RequireAdapter causes AdapterManagerImpl to wrap the adapters to >>>> throw an exception if adaption returns null. >>>> >>>> -Bertrand >> >
