Simple logging utility

Creates Logger object which can be used for logging with different level of verbosity. Log messages are in JSON format.

See also

lgr::Logger

Methods

Public methods

• Logger$new()

• Logger$set_name()

• Logger$set_log_level()

• Logger$set_printer()

• Logger$trace()

• Logger$debug()

• Logger$info()

• Logger$warn()

• Logger$error()

• Logger$fatal()

• Logger$clone()

---

Method new()

Creates Logger object.

Usage

Logger$new(
  level = c("info", "fatal", "error", "warn", "debug", "trace", "off", "all"),
  name = "ROOT",
  printer = NULL
)

Arguments

level

Log level. Allowed values: info, fatal, error, warn, debug, trace, off, all.

name

Logger name.

printer

Logger with sink defined by printer function. It should have signature function(timestamp, level, logger_name, pid, message). By default when printer = NULL logger writes message in JSON format to stdout.

---

Method set_name()

Sets logger name.

Usage

Logger$set_name(name = "ROOT")

Arguments

name

Logger name.

---

Method set_log_level()

Sets log level.

Usage

Logger$set_log_level(
  level = c("info", "fatal", "error", "warn", "debug", "trace", "off", "all")
)

Arguments

level

Log level. Allowed values: info, fatal, error, warn, debug, trace, off, all.

---

Method set_printer()

Sets function which defines how to print logs.

Usage

Logger$set_printer(FUN = NULL)

Arguments

FUN

Printer function. Should be a function with 6 formal arguments: timestamp, level, logger_name, pid, message.

---

Method trace()

Write trace message.

Usage

Logger$trace(msg, ...)

Arguments

msg

Log message.

...

Additionals params.

---

Method debug()

Write debug message.

Usage

Logger$debug(msg, ...)

Arguments

msg

Log message.

...

Additionals params.

---

Method info()

Write information message.

Usage

Logger$info(msg, ...)

Arguments

msg

Log message.

...

Additionals params.

---

Method warn()

Write warning message.

Usage

Logger$warn(msg, ...)

Arguments

msg

Log message.

...

Additionals params.

---

Method error()

Write error message.

Usage

Logger$error(msg, ...)

Arguments

msg

Log message.

...

Additionals params.

---

Method fatal()

Write fatal error message.

Usage

Logger$fatal(msg, ...)

Arguments

msg

Log message.

...

Additionals params.

---

Method clone()

The objects of this class are cloneable with this method.

Usage

Logger$clone(deep = FALSE)

Arguments

deep

Whether to make a deep clone.

Examples

# init logger
logger = Logger$new("info")
# write info message
logger$info("hello world")
#> {"timestamp":"2024-04-18 01:55:05.799259","level":"INFO","name":"ROOT","pid":3468,"msg":"hello world"}
# write extended log entry
logger$info("", context = list(message = "hello world", code = 0L))
#> {"timestamp":"2024-04-18 01:55:05.801573","level":"INFO","name":"ROOT","pid":3468,"msg":"","context":{"message":"hello world","code":0}}