materio-d8/web/themes/custom/materiotheme/vuejs/store/modules/showrooms.js

import { JSONAPI } from 'vuejs/api/json-axios'
import { REST } from 'vuejs/api/rest-axios'
import { MA } from 'vuejs/api/ma-axios'
import qs from 'querystring-es3'

export default {
  namespaced: true,

  // initial state
  state : {
    items: [],
  },

  // getters
  getters : {},

  // mutations
  mutations : {
    setItems (state, items) {
      state.items = state.items.concat(items)
    }
  },

  // actions
  actions : {
    getItems({ dispatch, commit, state }){
      REST.get(`/showrooms_rest?_format=json`, {})
        .then(({ data }) => {
          console.log('showrooms REST: data', data)
          commit('setItems',data)
        })
        .catch(( error ) => {
            console.warn('Issue with showrooms', error)
            Promise.reject(error)
        })
    }
  }
}