futile.logger (version 1.3.7)

flog.appender: 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)

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.

Value

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

See Also

flog.logger flog.layout

Examples

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')