There are some downsides to reference based approaches as well.
A.class: public void observe(final @Observes SimpleEvent event)
Z.class: public void observe(final @Observes(after=A.class) SimpleEvent
event)
If you later want to add B.class or C.class in the middle between A and Z, you
can't.
As well you can't really express things like "low priority" and "high priority"
EventLogger.class: public void observe(final @Observes(priority=1) Object
event)
On Mar 21, 2014, at 12:08 PM, Romain Manni-Bucau <[email protected]> wrote:
> -1 to index, it is what is in deltaspike, spec etc and it doesn't work
> by design (see the spec already defined constants). For such an
> internal thing we know where we want to bind our event so I still
> think referencing the event is better.
>
> Always better to say where you want to be than saying "i want to be
> here...almost" which is the index case.
> Romain Manni-Bucau
> Twitter: @rmannibucau
> Blog: http://rmannibucau.wordpress.com/
> LinkedIn: http://fr.linkedin.com/in/rmannibucau
> Github: https://github.com/rmannibucau
>
>
>
> 2014-03-21 20:02 GMT+01:00 David Blevins <[email protected]>:
>> For Observers maybe we can find another way to achieve OPENEJB-2082 without
>> binding one observer directly to another:
>>
>> public void observe(final @Observes(after = SimpleObserver.class)
>> SimpleEvent event)
>>
>> I can see that creating just as much of a mess as having too many events.
>> Having to sort each event is not exactly optimal for speed either.
>>
>> If we were to take a sorting based approach, maybe we can take a page from
>> the interceptor ordering of Java EE 7, based on unix start orders:
>>
>> @Priority(5)
>> public void observe(final @Observes SimpleEvent event)
>>
>> Default priority for all observers would be say, 5, like it is for a thread.
>> We would recommend 1-10 as the range and use a float rather than an int so
>> it can be easy to break a tie without complex hacking.
>>
>> Also as an optimization, we don't actually call the sort method unless one
>> of the Observers actually has a priority.
>>
>> Thoughts?
>>
>>
>> -David
>>
