vuex-persist
A Typescript-ready Vuex plugin that enables you to save the state of your app to a persisted storage like Cookies or localStorage.
Features
🎗 NEW IN V1.0.0- Support localForage and other Promise based stores
- Fix late restore of state for localStorage
- Automatically save store on mutation.
- Choose which mutations trigger store save, and which don't, using
filter
function - Works perfectly with modules in store
- Ability to save partial store, using a
reducer
function - Automatically restores store when app loads
- You can create mulitple VuexPersistence instances if you want to -
- Save some parts of the store to localStorage, some to sessionStorage
- Trigger saving to localStorage on data download, saving to cookies on authentication result
Compatibility
Installation
npm install --save vuex-persist
or
yarn add vuex-persist
Usage
Steps
Import it
import VuexPersistence from 'vuex-persist'
Create an object
const vuexLocal = new VuexPersistence({
storage: window.localStorage
})
Use it as Vue plugin. (in typescript)
const store = new Vuex.Store<State>({
state: { ... },
mutations: { ... },
actions: { ... },
plugins: [vuexLocal.plugin]
})
(or in Javascript)
const store = {
state: { ... },
mutations: { ... },
actions: { ... },
plugins: [vuexLocal.plugin]
}
Constructor Parameters -
When creating the VuexPersistence object, we pass an options
object
of type PersistOptions
.
Here are the properties, and what they mean -
Property | Type | Description |
---|---|---|
key | string | The key to store the state in the storage Default: 'vuex' |
storage | Storage (Web API) | localStorage, sessionStorage, localforage or your custom Storage object. Must implement getItem, setItem, clear etc. Default: window.localStorage |
saveState | function (key, state[, storage]) |
If not using storage, this custom function handles saving state to persistence |
restoreState | function (key[, storage]) => state |
If not using storage, this custom function handles retrieving state from storage |
reducer | function (state) => object |
State reducer. reduces state to only those values you want to save. By default, saves entire state |
filter | function (mutation) => boolean |
Mutation filter. Look at mutation.type and return true for only those ones which you want a persistence write to be triggered for. Default returns true for all mutations |
modules | string[] | List of modules you want to persist. (Do not write your own reducer if you want to use this) |
asyncStorage | boolean | Denotes if the store uses Promises (like localforage) or not Default: false |
Examples
Simple
Quick example -
import Vue from 'vue'
import Vuex from 'vuex'
import VuexPersistence from 'vuex-persist'
Vue.use(Vuex)
const store = new Vuex.Store<State>({
state: {
user: {name: 'Arnav'},
navigation: {path: '/home'}
},
plugins: [(new VuexPersistence()).plugin]
})
export default store
Detailed
Here is an example store that has 2 modules, user
and navigation
We are going to save user details into a Cookie (using js-cookie)
And, we will save the navigation state into localStorage whenever
a new item is added to nav items.
So you can use multiple VuexPersistence instances to store different
parts of your Vuex store into different storage providers.
import Vue from 'vue'
import Vuex, {Payload, Store} from 'vuex'
import VuexPersistence from 'vuex-persist'
import Cookies from 'js-cookie'
import {module as userModule, UserState} from './user'
import navModule, {NavigationState} from './navigation'
export interface State {
user: UserState,
navigation: NavigationState
}
Vue.use(Vuex)
const vuexCookie = new VuexPersistence<State, Payload>({
restoreState: (key, storage) => Cookies.getJSON(key),
saveState: (key, state, storage) => Cookies.set(key, state, {
expires: 3
}),
modules: ['user'], //only save user module
filter: (mutation) => (mutation.type == 'logIn' || mutation.type == 'logOut')
})
const vuexLocal = new VuexPersistence<State, Payload> ({
storage: window.localStorage,
reducer: state => ({navigation: state.navigation}), //only save navigation module
filter: mutation => (mutation.type == 'addNavItem')
})
const store = new Vuex.Store<State>({
modules: {
user: userModule,
navigation: navModule
},
plugins: [vuexCookie.plugin, vuexLocal.plugin]
})
export default store
Support Strict Mode
This now supports Vuex strict mode
(Keep in mind, NOT to use strict mode in production)
In strict mode, we cannot use store.replaceState
so instead we use a mutation
You'll need to keep in mind to add the RESTORE_MUTATION
to your mutations
See example below
To configure with strict mode support -
import Vue from 'vue'
import Vuex, {Payload, Store} from 'vuex'
import VuexPersistence from 'vuex-persist'
const vuexPersist = new VuexPersistence<any, any>({
strictMode: true, // This **MUST** be set to true
storage: localStorage,
reducer: (state) => ({ dog: state.dog }),
filter: (mutation) => (mutation.type === 'dogBark')
})
const store = new Vuex.Store<State>({
strict: true, // This makes the Vuex store strict
state: {
user: {
name: 'Arnav'
},
foo: {
bar: 'baz'
}
},
mutations: {
RESTORE_MUTATION: vuexPersist.RESTORE_MUTATION // this mutation **MUST** be named "RESTORE_MUTATION"
},
plugins: [vuexPersist.plugin]
})
Some of the most popular ways to persist your store would be -
- js-cookie to use browser Cookies
- window.localStorage (remains, across PC reboots, untill you clear browser data)
- window.sessionStorage (vanishes when you close browser tab)
- localForage Uses IndexedDB from the browser
Note on LocalForage and async stores
There is Window.Storage API as defined by HTML5 DOM specs, which implements the following -
interface Storage {
readonly length: number;
clear(): void;
getItem(key: string): string | null;
key(index: number): string | null;
removeItem(key: string): void;
setItem(key: string, data: string): void;
[key: string]: any;
[index: number]: string;
}
As you can see it is an entirely synchronous storage. Also note that it saves only string values. Thus objects are stringified and stored.
Now note the representative interface of Local Forage -
export interface LocalForage {
getItem<T>(key: string): Promise<T>
setItem<T>(key: string, data: T): Promise<T>
removeItem(key: string): Promise<void>
clear(): Promise<void>
length(): Promise<number>
key(keyIndex: number): Promise<string>
_config?: {
name: string
}
}
You can note 2 differences here -
- All functions are asynchronous with Promises (because WebSQL and IndexedDB are async)
- It works on objects too (not just strings)
I have made vuex-persist
compatible with both types of storages, but this comes
at a slight cost.
When using asynchronous (promise-based) storages, your state will not be
immediately restored into vuex from localForage. It will go into the event loop
and will finish when the JS thread is empty. This can invoke a delay of few seconds.
Issue #15 of this repository explains
what you can do to find out when store has restored.