| Node.js - jsonfile |
| ================ |
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| Easily read/write JSON files in Node.js. _Note: this module cannot be used in the browser._ |
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| [](https://www.npmjs.org/package/jsonfile) |
| [](http://travis-ci.org/jprichardson/node-jsonfile) |
| [](https://ci.appveyor.com/project/jprichardson/node-jsonfile/branch/master) |
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| <a href="https://github.com/feross/standard"><img src="https://cdn.rawgit.com/feross/standard/master/sticker.svg" alt="Standard JavaScript" width="100"></a> |
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| Why? |
| ---- |
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| Writing `JSON.stringify()` and then `fs.writeFile()` and `JSON.parse()` with `fs.readFile()` enclosed in `try/catch` blocks became annoying. |
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| Installation |
| ------------ |
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| npm install --save jsonfile |
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| API |
| --- |
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| * [`readFile(filename, [options], callback)`](#readfilefilename-options-callback) |
| * [`readFileSync(filename, [options])`](#readfilesyncfilename-options) |
| * [`writeFile(filename, obj, [options], callback)`](#writefilefilename-obj-options-callback) |
| * [`writeFileSync(filename, obj, [options])`](#writefilesyncfilename-obj-options) |
| |
| ---- |
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| ### readFile(filename, [options], callback) |
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| `options` (`object`, default `undefined`): Pass in any [`fs.readFile`](https://nodejs.org/api/fs.html#fs_fs_readfile_path_options_callback) 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. |
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| ```js |
| const jsonfile = require('jsonfile') |
| const file = '/tmp/data.json' |
| jsonfile.readFile(file, function (err, obj) { |
| if (err) console.error(err) |
| console.dir(obj) |
| }) |
| ``` |
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| You can also use this method with promises. The `readFile` method will return a promise if you do not pass a callback function. |
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| ```js |
| const jsonfile = require('jsonfile') |
| const file = '/tmp/data.json' |
| jsonfile.readFile(file) |
| .then(obj => console.dir(obj)) |
| .catch(error => console.error(error)) |
| ``` |
| |
| ---- |
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| ### readFileSync(filename, [options]) |
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| `options` (`object`, default `undefined`): Pass in any [`fs.readFileSync`](https://nodejs.org/api/fs.html#fs_fs_readfilesync_path_options) 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. |
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| ```js |
| const jsonfile = require('jsonfile') |
| const file = '/tmp/data.json' |
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| console.dir(jsonfile.readFileSync(file)) |
| ``` |
| |
| ---- |
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| ### writeFile(filename, obj, [options], callback) |
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| `options`: Pass in any [`fs.writeFile`](https://nodejs.org/api/fs.html#fs_fs_writefile_file_data_options_callback) 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`, or override `EOL` string or set `finalEOL` flag as `false` to not save the file with `EOL` at the end. |
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| ```js |
| const jsonfile = require('jsonfile') |
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| const file = '/tmp/data.json' |
| const obj = { name: 'JP' } |
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| jsonfile.writeFile(file, obj, function (err) { |
| if (err) console.error(err) |
| }) |
| ``` |
| Or use with promises as follows: |
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| ```js |
| const jsonfile = require('jsonfile') |
| |
| const file = '/tmp/data.json' |
| const obj = { name: 'JP' } |
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| jsonfile.writeFile(file, obj) |
| .then(res => { |
| console.log('Write complete') |
| }) |
| .catch(error => console.error(error)) |
| ``` |
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| **formatting with spaces:** |
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| ```js |
| const jsonfile = require('jsonfile') |
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| const file = '/tmp/data.json' |
| const obj = { name: 'JP' } |
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| jsonfile.writeFile(file, obj, { spaces: 2 }, function (err) { |
| if (err) console.error(err) |
| }) |
| ``` |
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| **overriding EOL:** |
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| ```js |
| const jsonfile = require('jsonfile') |
| |
| const file = '/tmp/data.json' |
| const obj = { name: 'JP' } |
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| jsonfile.writeFile(file, obj, { spaces: 2, EOL: '\r\n' }, function (err) { |
| if (err) console.error(err) |
| }) |
| ``` |
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| **disabling the EOL at the end of file:** |
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| ```js |
| const jsonfile = require('jsonfile') |
| |
| const file = '/tmp/data.json' |
| const obj = { name: 'JP' } |
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| jsonfile.writeFile(file, obj, { spaces: 2, finalEOL: false }, function (err) { |
| if (err) console.log(err) |
| }) |
| ``` |
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| **appending to an existing JSON file:** |
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| You can use `fs.writeFile` option `{ flag: 'a' }` to achieve this. |
| |
| ```js |
| const jsonfile = require('jsonfile') |
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| const file = '/tmp/mayAlreadyExistedData.json' |
| const obj = { name: 'JP' } |
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| jsonfile.writeFile(file, obj, { flag: 'a' }, function (err) { |
| if (err) console.error(err) |
| }) |
| ``` |
| |
| ---- |
| |
| ### writeFileSync(filename, obj, [options]) |
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| `options`: Pass in any [`fs.writeFileSync`](https://nodejs.org/api/fs.html#fs_fs_writefilesync_file_data_options) 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`, or override `EOL` string or set `finalEOL` flag as `false` to not save the file with `EOL` at the end. |
| |
| ```js |
| const jsonfile = require('jsonfile') |
| |
| const file = '/tmp/data.json' |
| const obj = { name: 'JP' } |
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| jsonfile.writeFileSync(file, obj) |
| ``` |
| |
| **formatting with spaces:** |
| |
| ```js |
| const jsonfile = require('jsonfile') |
| |
| const file = '/tmp/data.json' |
| const obj = { name: 'JP' } |
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| jsonfile.writeFileSync(file, obj, { spaces: 2 }) |
| ``` |
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| **overriding EOL:** |
| |
| ```js |
| const jsonfile = require('jsonfile') |
| |
| const file = '/tmp/data.json' |
| const obj = { name: 'JP' } |
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| jsonfile.writeFileSync(file, obj, { spaces: 2, EOL: '\r\n' }) |
| ``` |
| |
| **disabling the EOL at the end of file:** |
| |
| ```js |
| const jsonfile = require('jsonfile') |
| |
| const file = '/tmp/data.json' |
| const obj = { name: 'JP' } |
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| jsonfile.writeFileSync(file, obj, { spaces: 2, finalEOL: false }) |
| ``` |
| |
| **appending to an existing JSON file:** |
| |
| You can use `fs.writeFileSync` option `{ flag: 'a' }` to achieve this. |
| |
| ```js |
| const jsonfile = require('jsonfile') |
| |
| const file = '/tmp/mayAlreadyExistedData.json' |
| const obj = { name: 'JP' } |
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| jsonfile.writeFileSync(file, obj, { flag: 'a' }) |
| ``` |
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| License |
| ------- |
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| (MIT License) |
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| Copyright 2012-2016, JP Richardson <jprichardson@gmail.com> |