electron-config

Simple config handling for your Electron app or module


Keywords
electron, app, config, store, storage, conf, configuration, settings, preferences, json, data, persist, persistent, save
License
MIT
Install
npm install electron-config@2.0.0

Documentation

electron-store Build Status

Simple data persistence for your Electron app or module - Save and load user preferences, app state, cache, etc

Electron doesn't have a built-in way to persist user preferences and other data. This module handles that for you, so you can focus on building your app. The data is saved in a JSON file in app.getPath('userData').

You can use this module directly in both the main and renderer process.

Install

$ npm install electron-store

Requires Electron 5 or later.

Usage

const Store = require('electron-store');
const store = new Store();

store.set('unicorn', '🦄');
console.log(store.get('unicorn'));
//=> '🦄'

// Use dot-notation to access nested properties
store.set('foo.bar', true);
console.log(store.get('foo'));
//=> {bar: true}

store.delete('unicorn');
console.log(store.get('unicorn'));
//=> undefined

API

Changes are written to disk atomically, so if the process crashes during a write, it will not corrupt the existing config.

Store(options?)

Returns a new instance.

options

Type: object

defaults

Type: object

Default values for the store items.

Note: The values in defaults will overwrite the default key in the schema option.

schema

type: object

JSON Schema to validate your config data.

Under the hood, the JSON Schema validator ajv is used to validate your config. We use JSON Schema draft-07 and support all validation keywords and formats.

You should define your schema as an object where each key is the name of your data's property and each value is a JSON schema used to validate that property. See more here.

Example:

const Store = require('electron-store');

const schema = {
	foo: {
		type: 'number',
		maximum: 100,
		minimum: 1,
		default: 50
	},
	bar: {
		type: 'string',
		format: 'url'
	}
};

const store = new Store({schema});

console.log(store.get('foo'));
//=> 50

store.set('foo', '1');
// [Error: Config schema violation: `foo` should be number]

Note: The default value will be overwritten by the defaults option if set.

name

Type: string
Default: config

Name of the storage file (without extension).

This is useful if you want multiple storage files for your app. Or if you're making a reusable Electron module that persists some data, in which case you should not use the name config.

cwd

Type: string
Default: app.getPath('userData')

Storage file location. Don't specify this unless absolutely necessary!

If a relative path, it's relative to the default cwd. For example, {cwd: 'unicorn'} would result in a storage file in ~/Library/Application Support/App Name/unicorn.

encryptionKey

Type: string | Buffer | TypedArray | DataView
Default: undefined

This can be used to secure sensitive data if the encryption key is stored in a secure manner (not plain-text) in the Node.js app. For example, by using node-keytar to store the encryption key securely, or asking the encryption key from the user (a password) and then storing it in a variable.

In addition to security, this could be used for obscurity. If a user looks through the config directory and finds the config file, since it's just a JSON file, they may be tempted to modify it. By providing an encryption key, the file will be obfuscated, which should hopefully deter any users from doing so.

It also has the added bonus of ensuring the config file's integrity. If the file is changed in any way, the decryption will not work, in which case the store will just reset back to its default state.

When specified, the store will be encrypted using the aes-256-cbc encryption algorithm.

fileExtension

Type: string
Default: json

Extension of the config file.

You would usually not need this, but could be useful if you want to interact with a file with a custom file extension that can be associated with your app. These might be simple save/export/preference files that are intended to be shareable or saved outside of the app.

clearInvalidConfig

Type: boolean
Default: true

The config is cleared if reading the config file causes a SyntaxError. This is a good default, as the config file is not intended to be hand-edited, so it usually means the config is corrupt and there's nothing the user can do about it anyway. However, if you let the user edit the config file directly, mistakes might happen and it could be more useful to throw an error when the config is invalid instead of clearing. Disabling this option will make it throw a SyntaxError on invalid config instead of clearing.

serialize

Type: Function
Default: value => JSON.stringify(value, null, '\t')

Function to serialize the config object to a UTF-8 string when writing the config file.

You would usually not need this, but it could be useful if you want to use a format other than JSON.

deserialize

Type: Function
Default: JSON.parse

Function to deserialize the config object from a UTF-8 string when reading the config file.

You would usually not need this, but it could be useful if you want to use a format other than JSON.

accessPropertiesByDotNotation

Type: boolean
Default: true

Accessing nested properties by dot notation. For example:

const Store = require('electron-store');

const store = new Store();
store.set({
	foo: {
		bar: {
			foobar: '🦄'
		}
	}
});
console.log(store.get('foo.bar.foobar'));
//=> '🦄'

Alternatively, you can set this option to false so the whole string would be treated as one key.

const store = new Store({accessPropertiesByDotNotation: false});
store.set({
	`foo.bar.foobar`: '🦄'
});
console.log(store.get('foo.bar.foobar'));
//=> '🦄'

Instance

You can use dot-notation in a key to access nested properties.

The instance is iterable so you can use it directly in a for…of loop.

.set(key, value)

Set an item.

The value must be JSON serializable. Trying to set the type undefined, function, or symbol will result in a TypeError.

.set(object)

Set multiple items at once.

.get(key, [defaultValue])

Get an item or defaultValue if the item does not exist.

.has(key)

Check if an item exists.

.delete(key)

Delete an item.

.clear()

Delete all items.

.onDidChange(key, callback)

callback: (newValue, oldValue) => {}

Watches the given key, calling callback on any changes. When a key is first set oldValue will be undefined, and when a key is deleted newValue will be undefined.

Events are only triggered in the same process. So you won't get events in the main process if you trigger an event in a renderer process. See #39.

.onDidAnyChange(callback)

callback: (newValue, oldValue) => {}

Watches the whole config object, calling callback on any changes. oldValue and newValue will be the config object before and after the change, respectively. You must compare oldValue to newValue to find out what changed.

.size

Get the item count.

.store

Get all the data as an object or replace the current data with an object:

conf.store = {
	hello: 'world'
};

.path

Get the path to the storage file.

.openInEditor()

Open the storage file in the user's editor.

FAQ

Advantages over window.localStorage

Can I use YAML or another serialization format?

The serialize and deserialize options can be used to customize the format of the config file, as long as the representation is compatible with utf8 encoding.

Example using YAML:

const Store = require('electron-store');
const yaml = require('js-yaml');

const store = new Store({
	fileExtension: 'yaml',
	serialize: yaml.safeDump,
	deserialize: yaml.safeLoad
});

Related