@livy/file-handler

This Livy handler writes log records to a file.

Synchronous logger support: yes

Runtime: Node.js

Basic Example

const { FileHandler } = require('@livy/file-handler')

const handler = new FileHandler('logs.txt')

Installation

Install it via npm:

npm install @livy/file-handler

Options

The first argument to this handler's constructor is a file path to write to.

An object of options can be passed to the constructor as the second argument.

The following options are available:

append

Type: boolean

Default: true

Description: Whether DOM elements should be added at the beginning of the container instead of the end

bubble

Type: boolean

Default: true

Description: Controls whether records handled by this handler should bubble up to other handlers.

See also: Bubbling

formatter

Type: FormatterInterface

Default: new LineFormatter()

Description: The formatter to use.

level

Type: LogLevel

Default: 'debug'

Description: Controls which log records should be handled based on their log level.

prefix

Type: string | string[]

Default: []

Description: Prepend one or more lines to the file when it's first created. This can be useful to prepend header data, like in CSV.

Public API

bubble

Controls whether records handled by this handler should bubble up to other handlers. Initially set through the bubble option.

See also: Bubbling

close()

This handler implements the ClosableHandlerInterface. On cleanup, it closes the internal file handler.

You usually don't want to call this method manually. It is done automatically when a Node.js process exits / a browser page is closed.

defaultFormatter (read-only)

The formatter used by this handler if no formatter option is set.

formatter

This handler supports formatters by implementing the FormattableHandlerInterface.

level

The minimum log level of a log record to be considered by this handler. Initially set through the level option.

processors

This handler supports processors by implementing the ProcessableHandlerInterface.

reset()

This handler implements the ResettableInterface. Resetting it resets all attached processors.

You usually don't want to call this method manually on an individual handler. Consider calling it on the logger instead.