electron-json-storage

Easily write and read user settings in Electron apps

Electron lacks an easy way to persist and read user settings for your application. electron-json-storage implements an API somehow similar to localStorage to write and read JSON objects to/from the operating system application data directory, as defined by app.getPath('userData').

Related modules:

• electron-settings
• electron-store
• electron-storage

Installation

Install electron-json-storage by running:

$ npm install --save electron-json-storage

You can require this module from only the main process (remote module is deprecated after Electron 12).

Use in renderer process

set preload.js as preload file of BrowserWindow/webview

'use strict';

const storage = require('electron-json-storage-alt');
const { promisify } = require('util');
const { ipcRenderer, contextBridge } = require('electron');

contextBridge.exposeInMainWorld(
  '_electron_bridge',
  {
    storage: {
      get: promisify(storage.get),
      set: promisify(storage.set),
    },
  }
);

get storage from contextBridge:

const saveToStorage = async () => {
  await window._electron_bridge.storage.set('test_storage_current_time', new Date());
  const time = await window._electron_bridge.storage.get('test_storage_current_time');
  console.log('test_storage_current_time', time);
}

Documentation

• storage
  • .getDefaultDataPath() ⇒ String
  • .setDataPath(directory)
  • .getDataPath() ⇒ String
  • .get(key, [options], callback)
  • .getMany(keys, [options], callback)
  • .getAll([options], callback)
  • .set(key, json, [options], callback)
  • .has(key, [options], callback)
  • .keys([options], callback)
  • .remove(key, [options], callback)
  • .clear([options], callback)

storage.getDefaultDataPath() ⇒ String

Kind: static method of storage
Summary: Get the default data path
Returns: String - default data path
Access: public
Example

const defaultDataPath = storage.getDefaultDataPath()

storage.setDataPath(directory)

The default value will be used if the directory is undefined.

Kind: static method of storage
Summary: Set current data path
Access: public

Param	Type	Description
directory	String | Undefined	directory

Example

const os = require('os');
const storage = require('electron-json-storage');

storage.setDataPath(os.tmpdir());

storage.getDataPath() ⇒ String

Returns the current data path. It defaults to a directory called "storage" inside Electron's userData path.

Kind: static method of storage
Summary: Get current user data path
Returns: String - the user data path
Access: public
Example

const storage = require('electron-json-storage');

const dataPath = storage.getDataPath();
console.log(dataPath);

storage.get(key, [options], callback)

If the key doesn't exist in the user data, an empty object is returned. Also notice that the .json extension is added automatically, but it's ignored if you pass it yourself.

Passing an extension other than .json will result in a file created with both extensions. For example, the key foo.data will result in a file called foo.data.json.

Kind: static method of storage
Summary: Read user data
Access: public

Param	Type	Description
key	String	key
[options]	Object	options
[options.dataPath]	String	data path
callback	function	callback (error, data)

Example

const storage = require('electron-json-storage');

storage.get('foobar', function(error, data) {
  if (error) throw error;

  console.log(data);
});

storage.getMany(keys, [options], callback)

This function returns an object with the data of all the passed keys. If one of the keys doesn't exist, an empty object is returned for it.

Kind: static method of storage
Summary: Read many user data keys
Access: public

Param	Type	Description
keys	Array.<String>	keys
[options]	Object	options
[options.dataPath]	String	data path
callback	function	callback (error, data)

Example

const storage = require('electron-json-storage');

storage.getMany([ 'foobar', 'barbaz' ], function(error, data) {
  if (error) throw error;

  console.log(data.foobar);
  console.log(data.barbaz);
});

storage.getAll([options], callback)

This function returns an empty object if there is no data to be read.

Kind: static method of storage
Summary: Read all user data
Access: public

Param	Type	Description
[options]	Object	options
[options.dataPath]	String	data path
callback	function	callback (error, data)

Example

const storage = require('electron-json-storage');

storage.getAll(function(error, data) {
  if (error) throw error;

  console.log(data);
});

storage.set(key, json, [options], callback)

Kind: static method of storage
Summary: Write user data
Access: public

Param	Type	Description
key	String	key
json	Object	json object
[options]	Object	options
[options.dataPath]	String	data path
callback	function	callback (error)

Example

const storage = require('electron-json-storage');

storage.set('foobar', { foo: 'bar' }, function(error) {
  if (error) throw error;
});

storage.has(key, [options], callback)

Kind: static method of storage
Summary: Check if a key exists
Access: public

Param	Type	Description
key	String	key
[options]	Object	options
[options.dataPath]	String	data path
callback	function	callback (error, hasKey)

Example

const storage = require('electron-json-storage');

storage.has('foobar', function(error, hasKey) {
  if (error) throw error;

  if (hasKey) {
    console.log('There is data stored as `foobar`');
  }
});

storage.keys([options], callback)

Kind: static method of storage
Summary: Get the list of saved keys
Access: public

Param	Type	Description
[options]	Object	options
[options.dataPath]	String	data path
callback	function	callback (error, keys)

Example

const storage = require('electron-json-storage');

storage.keys(function(error, keys) {
  if (error) throw error;

  for (var key of keys) {
    console.log('There is a key called: ' + key);
  }
});

storage.remove(key, [options], callback)

Notice this function does nothing, nor throws any error if the key doesn't exist.

Kind: static method of storage
Summary: Remove a key
Access: public

Param	Type	Description
key	String	key
[options]	Object	options
[options.dataPath]	String	data path
callback	function	callback (error)

Example

const storage = require('electron-json-storage');

storage.remove('foobar', function(error) {
  if (error) throw error;
});

storage.clear([options], callback)

Kind: static method of storage
Summary: Clear all stored data in the current user data path
Access: public

Param	Type	Description
[options]	Object	options
[options.dataPath]	String	data path
callback	function	callback (error)

Example

const storage = require('electron-json-storage');

storage.clear(function(error) {
  if (error) throw error;
});

Support

If you're having any problem, please raise an issue on GitHub and we'll be happy to help.

Tests

Run the test suite by doing:

$ npm test

Contribute

• Issue Tracker: github.com/electron-userland/electron-json-storage/issues
• Source Code: github.com/electron-userland/electron-json-storage

Before submitting a PR, please make sure that you include tests, and that jshint runs without any warning:

$ npm run-script lint

License

The project is licensed under the MIT license.