[LOG4J2-1531] Change attribute and component values from String to Object

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 2.6.2
• Component/s: Core
• Epic Link: Plugin Ergonomics
• Assignee: Matt Sicker
• Reporter: Roger Kapsi
• Created: 18/Aug/16 17:53
• Updated: 28/Dec/23 18:29

Description

I was looking into creating a ConfigurationFactory/Builder that is backed by a Clojure DSL. It works rather beautifully until I tried to create a filter that is backed by a Clojure function. There is literally no way to pass arbitrary objects into a PluginFactory. All component values and attributes are assumed to be Strings.

(configuration
  (appender "stdout" "CONSOLE"
    (layout "PatternLayout"
      (attribute "pattern" "%d [%t] %-5level: %msg%n"))
    (filter "ClojureFilter"
      ;; This LoC doesn't work: addAttribute(key, value)
      ;; will store the toString() of the value. Bummer.
      ;; I'd the so easy and beautiful if it didn't.
      (attribute "fn" (fn [logger & more] (println logger)))))
  
  (logger "TestLogger" Level/INFO
    (appender-ref "rolling")
    (attribute "additivity" false))
  (root-logger Level/DEBUG 
    (appender-ref "rolling")))

@Plugin(name = "ClojureFilter", category = Node.CATEGORY, elementType = Filter.ELEMENT_TYPE, printObject = true)
class ClojureFilter extends AbstractFilter {
  @PluginFactory
  public static ClojureFilter createFilter(
      @PluginAttribute("fn") IFn fn, ...) {

     return new ClojureFilter(fn, ...);
  }
}

Issue Links

• relates to: LOG4J2-2600 Declarative Groovy Configuration DSL