# Node.js - jsonfile

Easily read/write JSON files.

[![npm Package](https://img.shields.io/npm/v/jsonfile.svg?style=flat-square)](https://www.npmjs.org/package/jsonfile) [![build status](https://secure.travis-ci.org/jprichardson/node-jsonfile.svg)](http://travis-ci.org/jprichardson/node-jsonfile) [![windows Build status](https://img.shields.io/appveyor/ci/jprichardson/node-jsonfile/master.svg?label=windows%20build)](https://ci.appveyor.com/project/jprichardson/node-jsonfile/branch/master)

[![Standard JavaScript](https://cdn.rawgit.com/feross/standard/master/sticker.svg)](https://github.com/feross/standard)

## 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](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse).

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

```js
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](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse).

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

```js
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](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify). Can also pass in `spaces` and override `EOL` string.

```js
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:**

```js
var jsonfile = require('jsonfile')

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

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

**overriding EOL:**

```js
var jsonfile = require('jsonfile')

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

jsonfile.writeFile(file, obj, {spaces: 2, EOL: '\r\n'}, function(err) {
  console.error(err)
})
```

**appending to an existing JSON file:**

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

```js
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](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify). Can also pass in `spaces` and override `EOL` string.

```js
var jsonfile = require('jsonfile')

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

jsonfile.writeFileSync(file, obj)
```

**formatting with spaces:**

```js
var jsonfile = require('jsonfile')

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

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

**overriding EOL:**

```js
var jsonfile = require('jsonfile')

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

jsonfile.writeFileSync(file, obj, {spaces: 2, EOL: '\r\n'})
```

**appending to an existing JSON file:**

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

```js
var jsonfile = require('jsonfile')

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

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

## License

(MIT License)

Copyright 2012-2016, JP Richardson <jprichardson@gmail.com>


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