Node.js - jsonfile

Easily read/write JSON files.

Why?

Writing JSON.stringify() and then fs.writeFile() and JSON.parse() with fs.readFile() enclosed in try/catch blocks became annoying.

Installation

npm install --save jsonfile

API

readFile(filename, [options], callback)

options (object, default undefined): Pass in any fs.readFile options or set reviver for a JSON reviver.

throws (boolean, default: true). If JSON.parse throws an error, pass this error to the callback. If false, returns null for the object.

var jsonfile = require('jsonfile')
var file = '/tmp/data.json'
jsonfile.readFile(file, function(err, obj) {
  console.dir(obj)
})

readFileSync(filename, [options])

options (object, default undefined): Pass in any fs.readFileSync options or set reviver for a JSON reviver.

throws (boolean, default: true). If an error is encountered reading or parsing the file, throw the error. If false, returns null for the object.

var jsonfile = require('jsonfile')
var file = '/tmp/data.json'

console.dir(jsonfile.readFileSync(file))

writeFile(filename, obj, [options], callback)

options: Pass in any fs.writeFile options or set replacer for a JSON replacer. Can also pass in spaces.

var jsonfile = require('jsonfile')

var file = '/tmp/data.json'
var obj = {name: 'JP'}

jsonfile.writeFile(file, obj, function (err) {
  console.error(err)
})

formatting with spaces:

var jsonfile = require('jsonfile')

var file = '/tmp/data.json'
var obj = {name: 'JP'}

jsonfile.writeFile(file, obj, {spaces: 2}, function(err) {
  console.error(err)
})

appending to an existing JSON file:

You can use fs.writeFile option {flag: 'a'} to achieve this.

var jsonfile = require('jsonfile')

var file = '/tmp/mayAlreadyExistedData.json'
var obj = {name: 'JP'}

jsonfile.writeFile(file, obj, {flag: 'a'}, function (err) {
  console.error(err)
})

writeFileSync(filename, obj, [options])

options: Pass in any fs.writeFileSync options or set replacer for a JSON replacer. Can also pass in spaces.

var jsonfile = require('jsonfile')

var file = '/tmp/data.json'
var obj = {name: 'JP'}

jsonfile.writeFileSync(file, obj)

formatting with spaces:

var jsonfile = require('jsonfile')

var file = '/tmp/data.json'
var obj = {name: 'JP'}

jsonfile.writeFileSync(file, obj, {spaces: 2})

appending to an existing JSON file:

You can use fs.writeFileSync option {flag: 'a'} to achieve this.

var jsonfile = require('jsonfile')

var file = '/tmp/mayAlreadyExistedData.json'
var obj = {name: 'JP'}

jsonfile.writeFileSync(file, obj, {flag: 'a'})

spaces

Global configuration to set spaces to indent JSON files.

default: null

var jsonfile = require('jsonfile')

jsonfile.spaces = 4

var file = '/tmp/data.json'
var obj = {name: 'JP'}

// json file has four space indenting now
jsonfile.writeFile(file, obj, function (err) {
  console.error(err)
})

Note, it's bound to this.spaces. So, if you do this:

var myObj = {}
myObj.writeJsonSync = jsonfile.writeFileSync
// => this.spaces = null

Could do the following:

var jsonfile = require('jsonfile')
jsonfile.spaces = 4
jsonfile.writeFileSync(file, obj) // will have 4 spaces indentation

var myCrazyObj = {spaces: 32}
myCrazyObj.writeJsonSync = jsonfile.writeFileSync
myCrazyObj.writeJsonSync(file, obj) // will have 32 space indentation
myCrazyObj.writeJsonSync(file, obj, {spaces: 2}) // will have only 2

License

(MIT License)

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