ReactiveFile

A lightweight library for creating a reactive ⚡️ binding between a JS object and a file.

Description

ReactiveFile is a library which handles parsing a data file and then auto-saving it reactively whenever you change the object.

Most popular filetypes (JSON, TOML, YAML, XML) are handled automatically. The API provides a set of tools that let you easily implement parsers and serializers for other languages.

The reactivity of a ReactiveFile object is deep by default.

Currently only supports Node.js (browser implementation is on the way)

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A simple example of a JSON file with a counter:

// data.json
{"counter": 0}

You can create a reactive binding with a few lines of code:

import * as ReactiveFile from 'reactivefile'
 
const data = await ReactiveFile.load('data.json')
data.$.counter++

The counter in data.json now has a value of 1.

Setup

Just run:

yarn add reactivefile

or:

npm install reactivefile

Usage

Import the package

import * as ReactiveFile from 'reactivefile'
// or
const ReactiveFile = require('reactivefile')

Create a reactive binding

const data = await ReactiveFile.load('data.json', options)
// use .loadSync(...) for synchronous loading instead

You can also create a ReactiveFile from an existing object and set a destination file

const data = ReactiveFile.from(response, {saveTo: 'destination.toml'})

Alter your data

data.$.lastAccess = new Date()
// data.$ is an alias for data.val

Adding new keys to your objects requires you to refresh your object's reactivity

data.$.newKey = 100
data.react()
data.$.newKey = 200

Create parsing and serializing functions for any data type and file extension

The implementation of the built-in toml type:

ReactiveFile.registerType('toml', str => toml.parse(str), obj => toml.stringify(obj))

You can also copy these functions from one type to another

ReactiveFile.assignType('yaml', 'yml')
// creates a yaml type with the same parser and serializer as yml

These types are also the file extensions — files with the json extension will be automatically handled by the json parser. You can override this behaviour by specifying the data type.

const data = await ReactiveFile.load('data.json', {type: 'toml'})
// reads toml from the data.json file (and saves in toml as well)

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Options

encoding

The encoding of the file. One of: 'ascii', 'base64', 'binary', 'hex', 'latin1', 'ucs-2', 'ucs2', 'utf-8', 'utf16le', 'utf8'.

type

The type/language of the file. Defaults to the file's extension.

saveTo

The destination file path. If set, saves your data to another file instead. Otherwise overwrites the original file.

reactive

Turns on/off the reactive binding. The object can be then saved with .save() or .saveSync() instead. Defaults to true.

deep

Turns on/off deep reactivity. Defaults to true.

asyncSave

Turns on/off asynchronous saving (instead of synchronous). Defaults to true.

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License

MIT