@mangar2/persist

Abstract

persists JSON objects to a file . Keeps several files and loads older files if the latest is broken

Contents

• Meta
• Class Persist
  • Parameters
  • Methods
    • readData
    • saveObjectToFile

Meta

File	persist.js
Abstract	persists JSON objects to a file . Keeps several files and loads older files if the latest is broken
Author	Volker Böhm
Copyright	Copyright ( c ) 2020 Volker Böhm
License	This software is licensed under the GNU LESSER GENERAL PUBLIC LICENSE Version 3 . It is furnished "as is" , without any support , and with no warranty , express or implied , as to its usefulness for any purpose .

Class Persist

new Persist(configuration)

Creates a new persistance support class

Example

const persist = new Persist( { keepFiles: 5 })
persist.saveObjectToFile('.', 'helloworld.json', { message: 'hello world' } )
const dataRead = persist.readData('.', 'helloworld.json')
// prints 'hello world'
console.log(dataRead.message)

Persist Parameters

Name	Type	Description
configuration	Object	configuration options

configuration properties

Name	Type	Description
keepFiles	number	amount of file versions to keep ( including the recently written file )

Persist Methods

readData

readData (directory, filenameBasis) => {Object}

Reads data from a file

readData Parameters

Name	Type	Description
directory	string	directory to delete file
filenameBasis	string	basis filename of the file . The

readData returns

Type	Description
Object	the object read .

saveObjectToFile

async saveObjectToFile (directory, filenameBasis, objectToSave) => {undefined}

Stringifies a JSON and writes it to a file . It will automatically add a timestamp to the provided "base" filename It does not throws errors , but logs write errors to the console

saveObjectToFile Parameters

Name	Type	Description
directory	string	directory to delete file
filenameBasis	string	basis filename of the file . The
objectToSave	Object	object to save as JSON

saveObjectToFile returns

Type	Description
undefined