Play Framework/Scala example source code file (LogTester.scala)

This example Play Framework source code file (LogTester.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Play Framework (and Scala) source code examples by using tags.

All credit for the original source code belongs to Play Framework; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Play Framework tags/keywords

api, appenderbase, collection, iloggingevent, list, logbuffer, logtester, mutable, none, option, play, play framework, root, t

The LogTester.scala Play Framework example source code

/*
 * Copyright (C) 2009-2014 Typesafe Inc. <http://www.typesafe.com>
 */
package play.it

import org.slf4j.LoggerFactory
import ch.qos.logback.core.AppenderBase
import ch.qos.logback.classic.spi.ILoggingEvent
import scala.collection.mutable.ListBuffer
import ch.qos.logback.classic.{Logger, LoggerContext, Level}
import play.api.Play

/**
 * Test utility for testing Play logs
 */
object LogTester {

  def withLogBuffer[T](block: LogBuffer => T) = {
    val ctx = LoggerFactory.getILoggerFactory.asInstanceOf[LoggerContext]
    val root = ctx.getLogger("ROOT")
    val rootLevel = root.getLevel
    val playLogger = Play.logger.logger.asInstanceOf[Logger]
    val playLevel = playLogger.getLevel
    val appender = new LogBuffer()
    appender.start()
    try {
      root.addAppender(appender)
      root.setLevel(Level.ALL)
      playLogger.addAppender(appender)
      playLogger.setLevel(Level.ALL)
      block(appender)
    } finally {
      root.detachAppender(appender)
      root.setLevel(rootLevel)
      playLogger.detachAppender(appender)
      playLogger.setLevel(playLevel)

    }
  }

}

class LogBuffer extends AppenderBase[ILoggingEvent] {
  private val buffer = ListBuffer.empty[ILoggingEvent]

  def append(eventObject: ILoggingEvent) = buffer.synchronized {
    buffer.append(eventObject)
  }

  def find(level: Option[Level] = None,
           logger: Option[String] = None,
           messageContains: Option[String] = None
            ): List[ILoggingEvent] = buffer.synchronized {
    val byLevel = level.fold(buffer) { l => buffer.filter(_.getLevel == l) }
    val byLogger = logger.fold(byLevel) { l => byLevel.filter(_.getLoggerName == l)}
    val byMessageContains = logger.fold(byLogger) { m => byLogger.filter(_.getMessage.contains(m))}
    byMessageContains.toList
  }
}