parsley/app/javascript/store/index.js

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

Vue.use(Vuex);

export default new Vuex.Store({
  strict: process.env.NODE_ENV !== 'production',
  state: {
    loading: false,
    error: null
  },
  getters: {

  },
  mutations: {
    setLoading(state, value) {
      state.loading = value;
    },

    setError(state, value) {
      state.error = value;
    }
  },
  actions: {

  }
});