Vuex Cannot read property of undefined

Question

I am trying to work with global variables with Vuex but also I do keep getting undefined error even I initialize Vuex using Vue.use();.

TypeError: Cannot read property 'isAuth' of undefined

store.js:

import Vue from 'vue';
import Vuex from 'vuex';

Vue.use(Vuex);

export default new Vuex.Store({
  isAuth: true,
});

main.js:

import store from './store/store';
....
new Vue({
  el: '#app',
  store,
  router,
  render: h => h(App),
.......

I call isAuth to see its value like this: this.$store.isAuth; and this causes the undefined error.

I did initialize Vuex in store.js, but am still having the undefined error. Is there something I am missing?

Answer 1

At a guess, this might work with what you're currently doing: this.$store.state.isAuth but I would do it like below.

I've not used the store in the way you have before but haven't had issues when using modules, try like this:

// authModule.js
const state = {
    isAuth: true
}

const getters = {
    getIsAuth (state) {
        return state.isAuth
    }
}

export default {
    state,
    getters
}

Then register it like so:

import authModule from './modules/authModule'
export default new Vuex.Store({
    modules: {
        authModule
    }
})

Then on your vue instance:

import {mapGetters} from 'vuex'

computed: {
    ...mapGetters({
        isAuth: 'getIsAuth'
    })
}

You can now access via this.isAuth. You can also access like: this.$store.state.authModule.isAuth

This is actually best practice according to their docs as it keeps things tidy when the project gets larger.