The 3 obvious choices: ScriptSelectorAppender, ScriptAppenderSelector, or AppenderScriptSelector. I actually prefer the second as it is an AppenderSelector that uses a Script (or rather, a Selector of an Appender that uses a Script). The first isn’t too bad as it is an Appender that is a ScriptSelector (or an Appender that acts as a Selector using a Script). The third choice is just terrible. I suppose with 3 words there are other choices as well but they probably suck too.
Ralph > On Sep 19, 2016, at 2:42 PM, Gary Gregory <garydgreg...@gmail.com> wrote: > > ScriptSelectorAppender? > > > On Sep 19, 2016 2:29 PM, "Ralph Goers" <ralph.go...@dslextreme.com > <mailto:ralph.go...@dslextreme.com>> wrote: > Actually, I do have one minor issue. It will cause confusion calling it > ScriptSelector. I am imagining the next step will be to create a > LayoutSelector that uses Scripts. I can also imagine a Selector for > AppenderRefs that uses Scripts. So calling it ScriptSelector is a bit > ambiguous, unless it is going to support creating any of these (which would > be hard since it extends AbstractAppender). > > Ralph > >> On Sep 19, 2016, at 12:02 AM, Gary Gregory <garydgreg...@gmail.com >> <mailto:garydgreg...@gmail.com>> wrote: >> >> Great, thanks Ralph. >> >> Gary >> >> On Sun, Sep 18, 2016 at 11:14 PM, Ralph Goers <ralph.go...@dslextreme.com >> <mailto:ralph.go...@dslextreme.com>> wrote: >> Yup to both. I’ll look at it tomorrow. >> >> Ralph >> >>> On Sep 18, 2016, at 10:31 PM, Gary Gregory <garydgreg...@gmail.com >>> <mailto:garydgreg...@gmail.com>> wrote: >>> >>> Nevermind, I can just overwrite the name in the Node's attribute map... >>> that works. I'd like a code review before or after merging to master. >>> >>> Gary >>> >>> On Sun, Sep 18, 2016 at 9:43 PM, Gary Gregory <garydgreg...@gmail.com >>> <mailto:garydgreg...@gmail.com>> wrote: >>> Hm, but how? org.apache.logging.log4j.core.appender.AbstractAppender.name >>> <http://org.apache.logging.log4j.core.appender.abstractappender.name/> is >>> final and there is no Appender.setName(String). Surely, we should not use >>> reflection... >>> >>> Gary >>> >>> On Sun, Sep 18, 2016 at 9:34 PM, Ralph Goers <ralph.go...@dslextreme.com >>> <mailto:ralph.go...@dslextreme.com>> wrote: >>> I haven’t looked at your code but when you create the “real” appender you >>> need to change its name to match the name of the selector so that >>> AppenderRefs work. >>> >>> Ralph >>> >>>> On Sep 18, 2016, at 9:24 PM, Gary Gregory <garydgreg...@gmail.com >>>> <mailto:garydgreg...@gmail.com>> wrote: >>>> >>>> I've implemented a first cut in the branch LOG4J2-1597 but I think I need >>>> some help to connect the final dot (or two). >>>> >>>> When I run the new unit test >>>> org.apache.logging.log4j.core.appender.ScriptSelectorAppenderTest, the >>>> status logger shows: >>>> >>>> 2016-09-18 21:19:09,393 main ERROR Unable to locate appender "SelectIt" >>>> for logger config "root" >>>> 2016-09-18 21:19:09,465 main ERROR Unable to locate appender "SelectIt" >>>> for logger config "root" >>>> 2016-09-18 21:19:09,485 main ERROR Unable to locate appender "SelectIt" >>>> for logger config "root" >>>> 2016-09-18 21:19:09,505 main ERROR Unable to locate appender "SelectIt" >>>> for logger config "root" >>>> >>>> Which initially makes sense: the appender created and returned by the >>>> builder of "SelectIt" is really an appender named "List2". >>>> >>>> I tried to add a hack in >>>> org.apache.logging.log4j.core.appender.ScriptSelector.Builder.build() to >>>> no avail: >>>> >>>> // This feels like a hack and it does not work: >>>> configuration.getAppenders().put(name, appender); >>>> >>>> Any thoughts? >>>> >>>> Gary >>>> >>>> On Sat, Sep 17, 2016 at 9:48 AM, Ralph Goers <ralph.go...@dslextreme.com >>>> <mailto:ralph.go...@dslextreme.com>> wrote: >>>> See inline >>>> >>>>> On Sep 16, 2016, at 10:31 PM, Gary Gregory <garydgreg...@gmail.com >>>>> <mailto:garydgreg...@gmail.com>> wrote: >>>>> >>>>> On Fri, Sep 16, 2016 at 8:38 PM, Ralph Goers <ralph.go...@dslextreme.com >>>>> <mailto:ralph.go...@dslextreme.com>> wrote: >>>>> Gary, >>>>> >>>>> I have no problem with components that can be dumbed down to do simple >>>>> things. I do have a problem with components that only do simple things >>>>> because people will constantly asked to have them be enhanced. >>>>> >>>>> As for what you are proposing here, can I just say “No”? >>>>> >>>>> Sure! :-) You can say whatever you want! :-) >>>>> >>>>> Having the Appenders element deferred just smells to me and having an >>>>> arbitrary script there just seems weird to me. Does it even have a >>>>> contract or is it a free-for-all? How does it cause multiple appenders to >>>>> be initialized? >>>>> >>>>> I think the RoutingAppender is a more appropriate solution. However, if >>>>> you want to dumb it down a bit and turn it into an AppenderSelector I’d >>>>> be ok with that. However, it would still be fairly similar to the >>>>> RoutingAppender. >>>>> >>>>> OK, so going back to one of your eariler messages: >>>>> >>>>> ==copy start== >>>>> >>>>> This sort of sounds like you want an Appender Selector, which would be an >>>>> Appender that uses a Selector to figure out which Appender to delegate >>>>> to. This is a bit like the PatternSelector. I would imagine it would make >>>>> sense to implement AppenderSelectors and LayoutSelectors. You probably >>>>> would want to dynamically initialize the Appenders much like the >>>>> RoutingAppender does. >>>>> >>>>> Maybe it would look like: >>>>> >>>>> <Appenders> >>>>> <ScriptSelector name=“" default=“”> >>>>> <Script language=“groovy”><![CDATA[ >>>>> if (System.getProperty”os.name >>>>> <http://os.name/>”).contains(“OS/390”)) then { >>>>> return “Socket”; >>>>> } else { >>>>> return “File”; >>>>> } >>>>> </Script> >>>>> <Appenders> >>>>> <SocketAppender name=“Socket” …/> >>>>> <FileAppender name=“File” …/> >>>>> </Appenders> >>>>> </ScriptSelector> >>>>> </Appenders> >>>>> >>>>> The thing is that this script would run every time the Selector was >>>>> accessed while it sounds like you would only want the script to run when >>>>> the Selector is initialized. We could do that too but the script would >>>>> need to be declared in a property that would only be used when the >>>>> selector is initialized. I would want to support being able to do both. >>>>> >>>>> ==copy end== >>>>> >>>>> This is indeed like the RoutingAppender _except_ that the whole point is >>>>> to do the script selection on start up. When you say that you'd want it >>>>> both ways, on start up and on each log event; what would the >>>>> configuration difference look like? >>>>> >>>>> But.. "Appender that uses a Selector to figure out which Appender to >>>>> delegate to" ... that is _so_ much like a RoutingAppender as to be >>>>> redundant, no? >>>> >>>> The difference is that a AppenderSelector can just implement the Builder >>>> or Factory and invoke the script at that time to figure out which Appender >>>> to create. It then returns that Appender. So while the AppenderSelector is >>>> technically an Appender, it really is just an AppenderBuilder. The >>>> RoutingAppender is a real Appender. >>>> >>>>> >>>>> What I want is for the script to determine which appender to use (once), >>>>> and instantiate that appender (once). There is no need for one appender >>>>> to delegate to another appender. >>>> >>>> And that is what I just described. >>>> >>>>> >>>>> The more general case is for the script to determine which appenders >>>>> (plural) to use (once), and instantiate those appenders (plural) (once). >>>>> There is no need for one appender to delegate to another appender list. I >>>>> do not have a use case for this today, but I do for the one appender case. >>>> >>>> An AppenderSelector could only instantiate a single Appender, not a group. >>>> If you wanted multiple appenders dynamically created this way you would >>>> using multiple selectors. I’m not sure I see that as a drawback. >>>> >>>> >>>>> >>>>> My goal would be explained to a user like this: "This feature helps you >>>>> build your configuration dynamically, all from the configuration file, to >>>>> determine which appender(s) to configure. This is different from using a >>>>> RoutingAppender which creates a level of indirection and decides what to >>>>> do for each log event _at runtime_" Yes, this is a simpler explanation >>>>> than also explaining the new role of scripts in the RoutingAppender but >>>>> you get the idea. >>>>> >>>>> I am open different solutions that meet the goal of building the >>>>> configuration dynamically, as if you'd done it in XML explicitly (or >>>>> JSON) but does not end up with one appender delegating to another. >>>>> >>>>> Thoughts? >>>>> >>>>> Gary >>>>> >>>> >>>> >>>> >>>> -- >>>> E-Mail: garydgreg...@gmail.com <mailto:garydgreg...@gmail.com> | >>>> ggreg...@apache.org <mailto:ggreg...@apache.org> >>>> Java Persistence with Hibernate, Second Edition >>>> <http://www.manning.com/bauer3/> >>>> JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> >>>> Spring Batch in Action <http://www.manning.com/templier/> >>>> Blog: http://garygregory.wordpress.com <http://garygregory.wordpress.com/> >>>> Home: http://garygregory.com/ <http://garygregory.com/> >>>> Tweet! http://twitter.com/GaryGregory <http://twitter.com/GaryGregory> >>> >>> >>> >>> -- >>> E-Mail: garydgreg...@gmail.com <mailto:garydgreg...@gmail.com> | >>> ggreg...@apache.org <mailto:ggreg...@apache.org> >>> Java Persistence with Hibernate, Second Edition >>> <http://www.manning.com/bauer3/> >>> JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> >>> Spring Batch in Action <http://www.manning.com/templier/> >>> Blog: http://garygregory.wordpress.com <http://garygregory.wordpress.com/> >>> Home: http://garygregory.com/ <http://garygregory.com/> >>> Tweet! http://twitter.com/GaryGregory <http://twitter.com/GaryGregory> >>> >>> >>> -- >>> E-Mail: garydgreg...@gmail.com <mailto:garydgreg...@gmail.com> | >>> ggreg...@apache.org <mailto:ggreg...@apache.org> >>> Java Persistence with Hibernate, Second Edition >>> <http://www.manning.com/bauer3/> >>> JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> >>> Spring Batch in Action <http://www.manning.com/templier/> >>> Blog: http://garygregory.wordpress.com <http://garygregory.wordpress.com/> >>> Home: http://garygregory.com/ <http://garygregory.com/> >>> Tweet! http://twitter.com/GaryGregory <http://twitter.com/GaryGregory> >> >> >> >> -- >> E-Mail: garydgreg...@gmail.com <mailto:garydgreg...@gmail.com> | >> ggreg...@apache.org <mailto:ggreg...@apache.org> >> Java Persistence with Hibernate, Second Edition >> <http://www.manning.com/bauer3/> >> JUnit in Action, Second Edition <http://www.manning.com/tahchiev/> >> Spring Batch in Action <http://www.manning.com/templier/> >> Blog: http://garygregory.wordpress.com <http://garygregory.wordpress.com/> >> Home: http://garygregory.com/ <http://garygregory.com/> >> Tweet! http://twitter.com/GaryGregory <http://twitter.com/GaryGregory>