Log Messages to Console and File with Optional JSON Format

A utility function for logging messages to the console and optionally to a log file. Messages can be stored as plain text (default) or in JSON format. Additionally, logging to a file can be disabled altogether.

Usage

logr_msg(
  message,
  level = "INFO",
  log_file = "app_log.txt",
  json = FALSE,
  store_log = FALSE
)

Arguments

message

A character string representing the message to be logged.

level

A character string indicating the log level. One of:

• "FATAL"

• "ERROR"

• "WARN"

• "SUCCESS"

• "INFO" (default)

• "DEBUG"

• "TRACE"

log_file

A character string specifying the path to the log file. Ignored if store_log = FALSE. Defaults to "app_log.txt".

json

A logical value indicating whether to save logs in JSON format. Defaults to FALSE. When TRUE, logs are written to log_file as JSON objects.

store_log

A logical value indicating whether logs should be saved to a file. Defaults to TRUE:

• If TRUE, logs are printed to the console and stored in log_file

• If FALSE, logs are printed to the console

Value

The function is called for its side effects of logging messages and does not return a value.

Details

• Console Logging: All messages are always logged to the console.

• File Logging: If store_log = TRUE and log_file is specified, messages are logged to the file in either plain text or JSON format.

• JSON Logs: When json = TRUE, log messages are stored as structured JSON objects with the fields:

  • timestamp: The time the message was logged.

  • level: The severity level of the log.

  • message: The actual log message.

See also

• logger::log_appender() for configuring log destinations.

• logger::log_formatter() for customizing log message formats.

• jsonlite::toJSON() for converting R objects to JSON.

Examples

# Log a simple informational message to the console
logr_msg("Application started.")

# Log an error message to the console and a file
logr_msg("Failed to connect to database.", level = "ERROR", log_file = "error_log.txt")

# Log a success message in JSON format
logr_msg("User login successful.", level = "SUCCESS", log_file = "app_log.json", json = TRUE)

# Log a warning message to the console only (no file storage)
logr_msg("Low memory warning.", level = "WARN", store_log = FALSE)