VueJS - Vuex Persisted State

Persisting State in Vuex Store

Persisting the Vuex state allows you to save the state of your VueJS application across page reloads and sessions. This guide covers how to use the vuex-persistedstate plugin to achieve this functionality.

Installing vuex-persistedstate

To use vuex-persistedstate in your VueJS project, you need to install it via npm or yarn:

# Install vuex-persistedstate via npm
$ npm install vuex-persistedstate

# Install vuex-persistedstate via yarn
$ yarn add vuex-persistedstate
                

Setting Up vuex-persistedstate

After installation, set up the vuex-persistedstate plugin in your Vuex store:

// store/index.js
import Vue from 'vue';
import Vuex from 'vuex';
import createPersistedState from 'vuex-persistedstate';

Vue.use(Vuex);

const store = new Vuex.Store({
  state: {
    count: 0
  },
  mutations: {
    increment(state) {
      state.count++;
    }
  },
  plugins: [createPersistedState()]
});

export default store;
                

Configuration Options

The vuex-persistedstate plugin provides several configuration options to control which parts of the state are persisted and how:

// store/index.js
import Vue from 'vue';
import Vuex from 'vuex';
import createPersistedState from 'vuex-persistedstate';

Vue.use(Vuex);

const store = new Vuex.Store({
  state: {
    count: 0,
    user: {
      name: '',
      email: ''
    }
  },
  mutations: {
    increment(state) {
      state.count++;
    },
    setUser(state, user) {
      state.user = user;
    }
  },
  plugins: [createPersistedState({
    paths: ['user'],
    storage: window.sessionStorage
  })]
});

export default store;
                

Paths

The paths option allows you to specify which parts of the state to persist:

// Only persist the user state
createPersistedState({
  paths: ['user']
})
                

Storage

The storage option allows you to specify where to store the persisted state. The default is localStorage, but you can also use sessionStorage:

// Use sessionStorage instead of localStorage
createPersistedState({
  storage: window.sessionStorage
})
                

Serializer

The serializer option allows you to specify how the state is serialized and deserialized:

// Custom serializer
createPersistedState({
  serializer: {
    serialize: state => JSON.stringify(state),
    deserialize: state => JSON.parse(state)
  }
})
                

Example: Persisting User State

Here is a complete example demonstrating how to persist the user state in a VueJS application:

// store/index.js
import Vue from 'vue';
import Vuex from 'vuex';
import createPersistedState from 'vuex-persistedstate';

Vue.use(Vuex);

const store = new Vuex.Store({
  state: {
    user: {
      name: '',
      email: ''
    }
  },
  mutations: {
    setUser(state, user) {
      state.user = user;
    }
  },
  plugins: [createPersistedState({
    paths: ['user']
  })]
});

export default store;

// App.vue



                

Best Practices

Follow these best practices when persisting state with Vuex:

• Store Only Necessary Data: Persist only the data that needs to survive page reloads or sessions to minimize storage usage.
• Use Session Storage for Temporary Data: Use sessionStorage for data that should not persist beyond the current session.
• Encrypt Sensitive Data: If you need to store sensitive data, consider encrypting it before persisting.
• Handle Storage Limitations: Be aware of storage limitations and handle errors gracefully when storage is full.
• Test Persistence: Test the persistence functionality thoroughly to ensure data is saved and restored correctly.

Summary

This guide provided an overview of persisting state in Vuex store using the vuex-persistedstate plugin, including installation, configuration options, examples, and best practices. By understanding and utilizing these techniques, you can effectively maintain application state across page reloads and sessions in your VueJS application.