Logger {log}R Documentation

Logger

Description

Create a logger.

Public fields

printer

A callback function to write the message to the console, must accept a single argument, defaults to cat.

predicate

A predicate function that determines whether to actually run the log, useful if you want to switch the logger on and off for debugging.

If the function returns TRUE the logger runs as normal, if FALSE the logger does not actually print, write or dump the messages.

Methods

Public methods

Method new()

Usage
Logger$new(prefix = NULL, write = FALSE, file = "log.log", sep = "\t")
Arguments
prefix

String to prefix all log messages.

write

Whether to write the log to the file.

file

Name of the file to dump the logs to, only used if write is TRUE.

sep

Separator between prefix and other flags and messages.

Details

Initialise

Examples
info <- Logger$new("INFO")
info$log("hello")

Method date()

Usage
Logger$date(format = "%d-%m-%Y")
Arguments
format

Formatter for the item, passed to format().

Details

Include the date in the log

Examples
info <- Logger$new("INFO")$date()
info$log("today")

Method time()

Usage
Logger$time(format = "%H:%M:%S")
Arguments
format

Formatter for the item, passed to format().

Details

Include the time in the log

Examples
info <- Logger$new("INFO")$time()
info$log("now")

Method unix()

Usage
Logger$unix()
Details

Include the time in the log

Examples
info <- Logger$new("INFO")$unix()
info$log("timestamp")

Method hook()

Usage
Logger$hook(fn)
Arguments
fn

A function that accepts one argument (string) and returns a modified version of that string.

Details

Preprocess the prefix with a custom function

Examples
err <- Logger$new("INFO")$hook(crayon::red)
err$log("hello")

Method dir()

Usage
Logger$dir()
Details

Include the directory in the log

Examples
info <- Logger$new("INFO")$dir()
info$log("directory")

Method flag()

Usage
Logger$flag(what)
Arguments
what

Function to run for every message logged or string to include in log message.

Details

Pass a custom flag

Examples
fl <- function(){
 paste0(sample(letters, 4), collapse = "")
}

info <- Logger$new("INFO")$flag(fl)
info$log("random")

Method log()

Usage
Logger$log(..., sep = " ", collapse = " ")
Arguments
...

Elements to compose message.

sep, collapse

Separators passed to paste().

Details

Log messages

Examples
info <- Logger$new("INFO")
info$log("Logger")

Method dump()

Usage
Logger$dump(file = "dump.log")
Arguments
file

Name of the file to dump the logs to.

Details

Dump the log to a file

Examples
info <- Logger$new("INFO")
info$log("hello")
\dontrun{info$dump()}

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

info <- Logger$new("INFO")$
 date()$
 time()$
 hook(crayon::blue)

info$log("Hello")
Sys.sleep(.7)
info$log("World")


## ------------------------------------------------
## Method `Logger$new`
## ------------------------------------------------

info <- Logger$new("INFO")
info$log("hello")

## ------------------------------------------------
## Method `Logger$date`
## ------------------------------------------------

info <- Logger$new("INFO")$date()
info$log("today")

## ------------------------------------------------
## Method `Logger$time`
## ------------------------------------------------

info <- Logger$new("INFO")$time()
info$log("now")

## ------------------------------------------------
## Method `Logger$unix`
## ------------------------------------------------

info <- Logger$new("INFO")$unix()
info$log("timestamp")

## ------------------------------------------------
## Method `Logger$hook`
## ------------------------------------------------

err <- Logger$new("INFO")$hook(crayon::red)
err$log("hello")

## ------------------------------------------------
## Method `Logger$dir`
## ------------------------------------------------

info <- Logger$new("INFO")$dir()
info$log("directory")

## ------------------------------------------------
## Method `Logger$flag`
## ------------------------------------------------

fl <- function(){
 paste0(sample(letters, 4), collapse = "")
}

info <- Logger$new("INFO")$flag(fl)
info$log("random")

## ------------------------------------------------
## Method `Logger$log`
## ------------------------------------------------

info <- Logger$new("INFO")
info$log("Logger")

## ------------------------------------------------
## Method `Logger$dump`
## ------------------------------------------------

info <- Logger$new("INFO")
info$log("hello")
## Not run: info$dump()
[Package log version 1.1.1 Index]