A LogEvent is a single unit of data that should be logged. LogEvents are usually created by a Logger, and then processed by one more Appenders. They do not need to be instantiated manually except for testing and experimentation; however, if you plan on writing your own Appenders or Layouts you need to understand LogEvents.

See also


Other docs relevant for extending lgr: event_list(), standardize_threshold()

Public fields


integer. The log_level / priority of the LogEvent. Use the active binding level_name to get the character representation instead.


POSIXct. The time when then the LogEvent was created.


character. The name of the calling function.


character. The log message.


Logger. A reference to the Logger that created the event (equivalent to get_logger(event$logger)).

Active bindings


list. All values stored in the LogEvent, including all custom fields, but not including event$.logger.


character. The log_level / priority of the LogEvent labelled according to getOption("lgr.log_levels")


character scalar. The name of the Logger that created this event, equivalent to event$.logger$name)


Public methods

Method new()

The arguments to LogEvent$new() directly translate to the fields stored in the LogEvent. Usually these values will be scalars, but (except for "logger") they can also be vectors if they are all of the same length (or scalars that will be recycled). In this case the event will be treated by the Appenders and Layouts as if several separate events.


  level = 400,
  timestamp = Sys.time(),
  caller = NA,
  msg = NA,


logger, level, timestamp, caller, msg

see Public fields.


All named arguments in ... will be added to the LogEvent as custom fields. You can store arbitrary R objects in LogEvents this way, but not all Appenders will support them. See AppenderJson for

Method clone()

The objects of this class are cloneable with this method.


LogEvent$clone(deep = FALSE)



Whether to make a deep clone.


lg <- get_logger("test") lg$error("foo bar")
#> ERROR [08:07:54.948] foo bar
# The last LogEvent produced by a Logger is stored in its `last_event` field lg$last_event # formatted console output
#> ERROR [2021-09-16 08:07:54] foo bar
lg$last_event$values # values stored in the event
#> $level #> [1] 200 #> #> $timestamp #> [1] "2021-09-16 08:07:54 UTC" #> #> $logger #> [1] "test" #> #> $caller #> [1] "eval" #> #> $msg #> [1] "foo bar" #>
# Also contains the Logger that created it as .logger lg$last_event$logger
#> [1] "test"
# equivalent to lg$last_event$.logger$name
#> [1] "test"
# This is really a reference to the complete Logger, so the following is # possible (though nonsensical) lg$last_event$.logger$last_event$msg
#> [1] "foo bar"
identical(lg, lg$last_event$.logger)
#> [1] TRUE
lg$config(NULL) # reset logger config
#> <Logger> [info] test #> #> inherited appenders: #> console: <AppenderConsole> [all] -> console