import Log from 'simple-isomorphic-logger/src/index.js'

public class | source

Log

Log stores tabular (array-of-array) data in JS memory on the browser, but streams it to disk using fs.writeSync() in nodejs server apps. .last is used to cache the last log row As a kind of limited guarantee of history on both platforms

Constructor Summary

Public Constructor
public	constructor(fname: string) Create Log with suggested file name in browser memory or on-disk in nodejs

Member Summary

Public Members
public	data: Array data array for browser and test usage
public	fd: number log file descriptor from open call
public	header: string[] header array for Log, as set by setHeader(header)
public	last: Object last item written to log
public	useFS: boolean if true, uses nodejs fs calls

Method Summary

Public Methods
public	lastByKey(k: *): number \| string \| undefined last value for some column recorded in Log
public	setHeader(x: string[]): Object sets header row and writes it to Log for csv-style Log.
public	write(x: Array \| number \| string): Object writes data to Log and sets .last

Public Constructors

public constructor(fname: string) source

Create Log with suggested file name in browser memory or on-disk in nodejs

Params:

Name	Type	Attribute	Description
fname	string		Suggested file name

Public Members

public data: Array source

data array for browser and test usage

public fd: number source

log file descriptor from open call

public header: string[] source

header array for Log, as set by setHeader(header)

public last: Object source

last item written to log

public useFS: boolean source

if true, uses nodejs fs calls

Public Methods

public lastByKey(k: *): number | string | undefined source

last value for some column recorded in Log

Params:

Name	Type	Attribute	Description
k	*

Return:

number | string | undefined

value from last write at column position matching header for given key

public setHeader(x: string[]): Object source

sets header row and writes it to Log for csv-style Log.

Params:

Name	Type	Attribute	Description
x	string[]		Header array giving names of columns for future writes

Return:

Object

Returns this Log; chainable

public write(x: Array | number | string): Object source

writes data to Log and sets .last

Params:

Name	Type	Attribute	Description
x	Array \| number \| string		data to write to Log's log file or memory

Return:

Object

returns Log object, chainable