On 12 Mar 2015 at 10:30:50, Marius Dumitru Florea ([email protected](mailto:[email protected])) wrote:
On Thu, Mar 12, 2015 at 10:41 AM, [email protected] wrote:
Hi devs,
As part of http://jira.xwiki.org/browse/XWIKI-11905, Edy has started using the Java @Priority annotation.
This seems very good and I personally didn’t know about this annotation before (maybe it’s been introduced not that long ago?). So for me it raises the question of: do we want to use this annotation more and how does it compare with what we’ve done so far.
I can think of a few places that could have used it:
* Macros.get/setPriority(). It should be possible to add support for @Priority and modify MacroTransformation to use that annotation. * Transformations. We have a jira issue opened for adding support for Priority in Transformation’s executions (in TransformationManager). * @DisposePriority (used by ECM). * TranslationBundle.get/setPriority() * … and probably some other places…
However, I think there’s a namespacing problem. For example imagine that we code a Macro and set @Priority on that Macro component. The ECM could interpret it as a dispose priority while the MacroTransformation could interpret it as an execution priority…
Globally I think that use an annotation for expressing priority is great and much better than what we’ve done in the past with get/setPriority() methods. It’s better because priority is not a business concept and we’re polluting the business interface with it.
Now, in order to fix the namespacing issue, I think that the best solution is that each module requiring some priority should introduce its own annotation and should NOT depend on the @Priority one from the JDK (i.e. we ban the usage of it).
We could also define a generic Priority annotation that has a role (namespace) besides the value.
@Priority(role = org.xwiki.rendering.macro.Macro.class, value = 210)
Yes, I thought about it too, but discarded it because it’s less nice than having a strongly typed annotation IMO.
The advantage I see is that we can write a generic component to retrieve the instance list sorted by priority, for a given role.
Retrieving a given annotation is a one liner in java so it’s not really an issue. Thanks -Vincent
Thanks, Marius
WDYT?
Thanks -Vincent
W