Vue/Vuex - Load state from JSON file - json

Question

I am trying to bulid a simple app using Vue / Vuex starting from vue-cli webpack template.
The app works fine but I would like to add the possibility to load and save the state in a JSON file.
Is there a best practice in order to do that ?
My first idea was to read the data into the file store.js
import Vue from 'vue'
import Vuex from 'vuex'
import fs from 'fs'
// Read file
let loaded = null
fs.readFile('./data.json', 'utf8', (err, data) => {
if (err) throw err;
loaded = data;
})
Vue.use(Vuex)
const state = {
notes: loaded,
activeNote: {}
}
...
...
But I am getting error when I try to import fs module.

Answer 1

There are great plugins available for exactly what you're trying to do.
Basically, having Vuex and defining a state is he way to go, however, you should do it a little different.
Take a look at this plugin:
https://github.com/robinvdvleuten/vuex-persistedstate
Since you're using Webpack it is pretty easy to install, use yarn add vuex-persistedstate for example..
Then, you import the plugin using import createPersistedState from 'vuex-persistedState'.
Now you change up your store a little bit, doing something like this:
export const store = new Vuex.Store({
state: {
yourVar: 0
},
mutations: {
changeValue (state, number) {
state.yourVar += number
}
},
plugins: [createPersistedState()]
})
That's basically it. All you need to do is add the plugin line to your Vuex store and all variable data inside your state will be saved in the browsers localStorage by default. Of course, you can read through the GitHub repository to see how you can use sessions, cookies etc, but that should work just fine.
The important part here are your mutations, since everything you want to do with your store variables HAVE to be declared by a mutation function.
If you try to modify your stored variables using ordinary functions, you'll get some warnings. The reason behind this is to ensure that no unexpected mutation of your data will take place, so you have to explicitly define what you want your program to accept in order to change your variables.
Also, using the export const store before your new Vuex.Store allows you to import that state in any of your Vue components and call the mutation functions out of there as well, using store.commit('changeValue', number).
I hope this answer helps you out a little bit, I was struggling with the exact same problem about 2 days ago and this is working like a charm ;)