Simple data persistence for your Electron app or module - Save and load user settings, app state, cache, etc
npm install electron-store> Simple data persistence for your Electron app or module - Save and load user settings, app state, cache, etc
Electron doesn't have a built-in way to persist user settings 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 named config.json in app.getPath('userData').
You can use this module directly in both the main and renderer process. For use in the renderer process only, you need to call Store.initRenderer() in the main process, or create a new Store instance (new Store()) in the main process.
``sh`
npm install electron-store
Requires Electron 30 or later.
> [!NOTE]
> This package is native ESM and no longer provides a CommonJS export. If your project uses CommonJS, you will have to convert to ESM. More info about Electron and ESM. Please don't open issues for questions regarding CommonJS and ESM.
`js
import Store from '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
`
Changes are written to disk atomically, so if the process crashes during a write, it will not corrupt the existing config.
Returns a new instance.
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-2020-12 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:
`js
import Store from '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.
#### migrations
Type: object
Important: I cannot provide support for this feature. It has some known bugs. I have no plans to work on it, but pull requests are welcome.
You can use migrations to perform operations to the store whenever a version is upgraded.
The migrations object should consist of a key-value pair of 'version': handler. The version can also be a semver range.
Example:
`js
import Store from 'electron-store';
const store = new Store({
migrations: {
'0.0.1': store => {
store.set('debugPhase', true);
},
'1.0.0': store => {
store.delete('debugPhase');
store.set('phase', '1.0.0');
},
'1.0.2': store => {
store.set('phase', '1.0.2');
},
'>=2.0.0': store => {
store.set('phase', '>=2.0.0');
}
}
});
`
Type: Function\undefined
Default:
The given callback function will be called before each migration step.
The function receives the store as the first argument and a context object as the second argument with the following properties:
- fromVersion - The version the migration step is being migrated from.toVersion
- - The version the migration step is being migrated to.finalVersion
- - The final version after all the migrations are applied.versions
- - All the versions with a migration step.
This can be useful for logging purposes, preparing migration data, etc.
Example:
`js
import Store from 'electron-store';
console.log = someLogger.log;
const mainConfig = new Store({
beforeEachMigration: (store, context) => {
console.log([main-config] migrate from ${context.fromVersion} → ${context.toVersion});
},
migrations: {
'0.4.0': store => {
store.set('debugPhase', true);
}
}
});
const secondConfig = new Store({
beforeEachMigration: (store, context) => {
console.log([second-config] migrate from ${context.fromVersion} → ${context.toVersion});`
},
migrations: {
'1.0.1': store => {
store.set('debugPhase', true);
}
}
});
#### name
Type: string\'config'
Default:
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\app.getPath('userData')
Default:
Storage file location. Don't specify this unless absolutely necessary! By default, it will pick the optimal location by adhering to system conventions. You are very likely to get this wrong and annoy users.
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\undefined
Default:
Note that this is not intended for security purposes, since the encryption key would be easily found inside a plain-text Node.js app.
Its main use is 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.
When specified, the store will be encrypted using the aes-256-cbc encryption algorithm.
#### fileExtension
Type: string\'json'
Default:
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\false
Default:
The config is cleared if reading the config file causes a SyntaxError. This is a good behavior for unimportant data, 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.
#### serialize
Type: Function\value => JSON.stringify(value, null, '\t')
Default:
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\JSON.parse
Default:
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\true
Default:
Accessing nested properties by dot notation. For example:
`js
import Store from '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.
`js
const store = new Store({accessPropertiesByDotNotation: false});
store.set({
foo.bar.foobar: '🦄'
});
console.log(store.get('foo.bar.foobar'));
//=> '🦄'
`
#### watch
Type: boolean\false
Default:
Watch for any changes in the config file and call the callback for onDidChange or onDidAnyChange if set. This is useful if there are multiple processes changing the same config file, for example, if you want changes done in the main process to be reflected in a renderer process.
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.
#### .reset(...keys)
Reset items to their default values, as defined by the defaults or schema option.
Use .clear() to reset all items.
#### .has(key)
Check if an item exists.
#### .delete(key)
Delete an item.
#### .appendToArray(key, value)
Append an item to an array.
If the key doesn't exist, it will be created as an array. If the key exists and is not an array, a TypeError will be thrown.
The value must be JSON serializable. Trying to set the type like undefined, function, or symbol will result in a TypeError.
`js
store.set('items', [{name: 'foo'}]);
store.appendToArray('items', {name: 'bar'});
console.log(store.get('items'));
//=> [{name: 'foo'}, {name: 'bar'}]
// Creates array if key doesn't exist
store.appendToArray('newItems', 'first');
console.log(store.get('newItems'));
//=> ['first']
`
#### .clear()
Delete all items.
This resets known items to their default values, if defined by the defaults or schema option.
#### .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.
Returns a function which you can use to unsubscribe:
`js
const unsubscribe = store.onDidChange(key, callback);
unsubscribe();
`
#### .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.
Returns a function which you can use to unsubscribe:
`js
const unsubscribe = store.onDidAnyChange(callback);
unsubscribe();
`
#### .size
Get the item count.
#### .store
Get all the data as an object or replace the current data with an object:
`js
import Store from 'electron-store';
const store = new Store();
store.store = {
hello: 'world'
};
`
#### .path
Get the path to the storage file.
#### .openInEditor()
Open the storage file in the user's editor.
Returns a promise that resolves when the editor has been opened, or rejects if it failed to open.
Initializer to set up the required ipc communication channels for the module when a Store instance is not created in the main process and you are creating a Store instance in the Electron renderer process only.
In the main process:
`js
import Store from 'electron-store';
Store.initRenderer();
`
And in the renderer process:
`js
import Store from 'electron-store';
const store = new Store();
store.set('unicorn', '🦄');
console.log(store.get('unicorn'));
//=> '🦄'
`
#### 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:
`js
import Store from 'electron-store';
import yaml from 'js-yaml';
const store = new Store({
fileExtension: 'yaml',
serialize: yaml.safeDump,
deserialize: yaml.safeLoad
});
`
#### How do I get store values in the renderer process when my store was initialized in the main process?
The store is not a singleton, so you will need to either initialize the store in a file that is imported in both the main and renderer process, or you have to pass the values back and forth as messages. Electron provides a handy invoke/handle API that works well for accessing these values.
`js`
ipcMain.handle('getStoreValue', (event, key) => {
return store.get(key);
});
`js``
const foo = await ipcRenderer.invoke('getStoreValue', 'foo');
#### Can I use it for large amounts of data?
This package is not a database. It simply uses a JSON file that is read/written on every change. Prefer using it for smaller amounts of data like user settings, value caching, state, etc.
If you need to store large blobs of data, I recommend saving it to disk and to use this package to store the path to the file instead.
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