flog.appender {futile.logger}

Manage appenders for loggers

Description

Provides functions for adding and removing appenders.

Arguments

...

Used internally by lambda.r

Usage

# Get the appender for the given logger
flog.appender(name) %::% character : Function
flog.appender(name='ROOT')

# Set the appender for the given logger
flog.appender(fn, name='ROOT')

# Print log messages to the console
appender.console()

# Write log messages to a file
appender.file(file)

# Write log messages to console and a file
appender.tee(file)

Details

Appenders do the actual work of writing log messages to some target. To use an appender in a logger, you must register it to a given logger. Use flog.appender to both access and set appenders.

The ROOT logger by default uses appender.console.

appender.console is a function that writes to the console. No additional arguments are necessary when registering the appender via flog.appender.

appender.file writes to a file, so you must pass an additional file argument to the function. To change the file name, just call flog.appender(appender.file(file)) again with a new file name.

To use your own appender create a function that takes a single argument, which represents the log message. You need to pass a function reference to flog.appender.

appender.tee writes to both the console and file.

Value

When getting the appender, flog.appender returns the appender function. When setting an appender, flog.appender has no return value.

Author(s)

Brian Lee Yung Rowe

See Also

flog.logger flog.layout

Examples

## Not run: 
flog.appender(appender.console(), name='my.logger')

# Set an appender to the logger named 'my.package'. Any log operations from
# this package will now use this appender.
flog.appender(appender.file('my.package.out'), 'my.package')

## End(Not run)