Cognito Hosted UI + Vue.js

HelloWorld.vue

<template>
  <div>
    <b-container>
      <b-row align-h="center">
        <div v-if="!signedIn">
          <b-button variant="success" @click="signIn">Sign in with Cognito</b-button>
        </div>
        <div v-if="signedIn">
          <h4>Welcome, {{ username }}!</h4>
          <b-button variant="danger" @click="signOut">Sign out</b-button>
        </div>
      </b-row>
    </b-container>
  </div>
</template>

<script>
import { Auth, Hub } from "aws-amplify";
export default {
  name: "HelloWorld",
  props: {},
  data() {
    return {
      signedIn: false,
      username: String
    };
  },
  methods: {
    signIn: () => {
      console.log("HelloWorld signIn()");
      Auth.federatedSignIn(); // Cognito is the default provider
    },
    signOut: () => {
      console.log("HelloWorld signOut()");
      Auth.signOut()
        .then(data => {
          console.log(data);
        })
        .catch(err => console.log(err));
    }
  },
  mounted() {
    console.log("HelloWorld mounted()");

    Hub.listen("auth", ({ payload: { event, data } }) => {
      console.log(`Auth event: ${event}`);
      switch (event) {
        case "signIn":
          console.log("signIn data: " + JSON.stringify(data));
          this.signedIn = true;
          this.username = data.username;
          break;
        case "signOut":
          this.signedIn = false;
          this.username = null;
          break;
      }
    });

    Auth.currentAuthenticatedUser()
      .then(user => {
        console.log("Username: " + user.username);
        console.log("Refreshing access and id tokens");
        Auth.currentSession()
          .then(data => console.log(data))
          .catch(err => console.log("Error refreshing tokens: " + err));
        this.signedIn = true;
        this.username = user.username;
      })
      .catch(err => console.log("Auth.currentAuthenticatedUser(): " + err));
  }
};
</script>

<style scoped>
</style>

main.js

import Vue from 'vue'
import App from './App.vue'
import router from './router'
import Amplify, * as AmplifyModules from 'aws-amplify'
import { AmplifyEventBus, AmplifyPlugin } from 'aws-amplify-vue'
import { BootstrapVue } from 'bootstrap-vue'

import "bootstrap/dist/css/bootstrap.css";
import "bootstrap-vue/dist/bootstrap-vue.css";

Vue.use(AmplifyPlugin, AmplifyModules)
Vue.use(BootstrapVue)

Vue.config.productionTip = false

Amplify.configure({
  Auth: {
    region: 'us-east-1',
    userPoolId: 'us-east-1_XXXXXXXX',
    userPoolWebClientId: 'YOUR COGNITO APP CLIENT ID',
    oauth: {
      domain: 'YOUR COGNITO DOMAIN',
      scope: ['email', 'profile', 'openid'],
      redirectSignIn: 'http://localhost:8080/',
      redirectSignOut: 'http://localhost:8080/',
      responseType: 'code'
    }
  },
});

AmplifyEventBus.$on('authState', info => {
  console.log(`Here is the auth event that was just emitted by an Amplify component: ${info}`)
});

new Vue({
  router,
  render: h => h(App)
}).$mount('#app')