App.vue

<template>
  <v-app>
    <v-card>
      Some random content
    </v-card>
  </v-app>
</template>

<script language="javascript" type="text/javascript" src="jslibs/web3.min.js"></script>
<script>
export default {
  name: 'App',
  data () {
    return {
      web3Provider: null,
      contract: null,
      account: '0x0',
    }
  },

  async mounted() {
    await this.initProvider();
  },

  methods: {
    async initProvider() {
      if (typeof web3 !== 'undefined') {
        this.web3Provider = web3.currentProvider;
        console.log(web3.currentProvider);
        //ethereum.enable();
        web3 = new Web3(web3.currentProvider);
        console.log(web3.version);
        this.account = web3.eth.accounts[0];
      } else {
        console.log("Please install Metamask to continue.");
      }

      setInterval(function() {
        // Check if account has changed
        if (web3.eth.accounts[0] !== this.account) {
          this.account = web3.eth.accounts[0];
          alert("You changed account!");
        }
      }, 100);
    },
  }
}
</script>