根据用户是否登录 AWS amplify 有条件地呈现导航栏

Question

I am attempting to conditionally render a and based on whether or not a user is signed in or not using AWS amplify and Vue 3 for the frontend. I have been able to get it to not render and then render on sign in but when I log back out the navbar elements are still there and should have disappeared. I am new to Vue, so this maybe an easy fix but am unsure. I have tried making using both computed and a watch to try and force update the computed but that is not working. Any help would be much appreciated. The code is below:

<template>
  <header>
    <nav class="navbar">
      <router-link @click="closeMenu" to="/" class="nav-branding"
        >Portal</router-link
      >
      <ul :class="[menuIsOpen ? 'active' : '', 'nav-menu']" v-show="isSignedIn">
        <li @click="toggleMenu" class="nav-item">
          <router-link to="/pensions" class="nav-link">Pensions</router-link>
        </li>
        <li @click="toggleMenu" class="nav-item">
          <router-link to="/benefits" class="nav-link">Benefits</router-link>
        </li>
        <li @click="toggleMenu" class="nav-item">
          <router-link to="/annual-leave" class="nav-link"
            >Annual Leave</router-link
          >
        </li>
        <li @click="signOut" class="nav-item">
          <router-link to="/" class="nav-link">Sign Out</router-link>
        </li>
      </ul>
      <div
        @click="toggleMenu"
        :class="[menuIsOpen ? 'active' : '', 'hamburger']"
        v-show="isSignedIn"
      >
        <span class="bar"></span>
        <span class="bar"></span>
        <span class="bar"></span>
      </div>
    </nav>
  </header>
  <div :class="[menuIsOpen ? 'pushed' : 'static']"></div>
</template>

<script>
import { Auth } from "aws-amplify";

export default {
  name: "NavBar",
  data() {
    return {
      menuIsOpen: false,
    };
  },
  methods: {
    toggleMenu() {
      this.menuIsOpen = !this.menuIsOpen;
    },
    closeMenu() {
      this.menuIsOpen = false;
    },
    async signOut() {
      try {
        await Auth.signOut();
        // navigate to the login page or another route
        this.$router.push("/");
      } catch (err) {
        console.log(err);
      }
    },
    async isUser() {
      try {
        await Auth.currentAuthenticatedUser();
        return true;
      } catch {
        return false;
      }
    },
  },
  computed: {
    isSignedIn() {
      return this.isUser();
    },
    watch: {
      isSignedIn() {
        this.$forceUpdate();
      },
    },
  },
};
</script>

<style>
header {
  height: auto;
  background-color: #0d1520;
}

li {
  list-style: none;
}

a {
  color: white;
  text-decoration: none;
}

.navbar {
  min-height: 70px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 24px;
}

.nav-menu {
  display: flex;
  justify-content: space-around;
  align-items: center;
  gap: 60px;
}

.nav-branding {
  font-size: 2rem;
  color: #03e9f4;
}

.nav-branding:hover {
  text-shadow: 0 0 5px #03e9f4, 0 0 25px #03e9f4, 0 0 50px #03e9f4,
    0 0 100px #03e9f4;
}

.nav-link {
  transition: 0.7s ease;
  color: #03e9f4;
}

.nav-link:hover {
  text-shadow: 0 0 5px #03e9f4, 0 0 25px #03e9f4, 0 0 50px #03e9f4,
    0 0 100px #03e9f4;
}

.hamburger {
  display: none;
  cursor: pointer;
}

.bar {
  display: block;
  width: 25px;
  height: 3px;
  margin: 5px auto;
  transition: all 0.3s ease-in-out;
  background-color: #03e9f4;
}

.hamburger:hover .bar {
  box-shadow: 0 0 5px #03e9f4, 0 0 25px #03e9f4, 0 0 50px #03e9f4,
    0 0 100px #03e9f4;
}

@media (max-width: 768px) {
  .static {
    transition: all 0.5s ease-in-out;
    padding-top: 0;
    z-index: 0;
    background-color: #151f31;
  }

  .pushed {
    padding-top: 168px;
    transition: padding 0.3s ease-in-out;
    transition-delay: 0.2;
    z-index: 0;
    background-color: #151f31;
  }
  .hamburger {
    display: block;
  }

  .hamburger.active .bar:nth-child(2) {
    opacity: 0;
  }
  .hamburger.active .bar:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
  }
  .hamburger.active .bar:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
  }

  .nav-menu {
    position: fixed;
    left: 100%;
    top: 70px;
    gap: 0;
    flex-direction: column;
    background-color: #0d1520;
    width: 100%;
    text-align: center;
    transition: 0.5s;
  }

  .nav-item {
    margin: 16px 0;
  }

  .nav-menu.active {
    z-index: 1;
    left: 0;
  }
}
</style>

Answer 1

Update

There're way too many "unknowns" in your problem thus it's difficult to give you a working answer. I'll give you hints but please read the Vue docs carefully to understand how to implement them and to also better understand the framework.

As you mentioned in the comments below, you're handling your sign in function in a "sibling" component and that both components are imported in the App.vue .

App.vue
views/
... NavBar.vue
... Login.vue

Option #1

Without the use of a state management, what you can do is move this code:

export default {
  data() {
    return { isSignedIn: false };
  },
  methods: {
    async isAuthenticated() {
      try {
        await Auth.currentAuthenticatedUser();

        this.isSignedIn = true;
      } catch {
        this.isSignedIn = false;
      }
    },
  }
  async mounted() {
    await this.isAuthenticated();
  }
}

in your App.vue, then use an emitter in the login component so that your App.vue can "listen" whenever the user has logged in successfully. You can use this.isAuthenticated() as the callback function in the emit event prop. Then, pass the this.isSignedIn state as aprop in your navbar component:

Login.vue

export default {
  ...
  methods: {
    signInUser() {
      /** your sign in logic */
      this.$emit('signIn')
    }
  }
  ...
}

App.vue

<!-- Sample template -->
<NavBar :show="isSignedIn" />
<Login @sign-in="isAuthenticated" />

Navbar.vue

export default {
  props: ['show'] // you can then pass show in your v-show
}

Option #2

You can also conditionally render the entire navbar component. However, you need to re-structure your templates a bit:

App.vue

<Navbar v-show="isSignedIn"/>

Option #3

Ideally, App should not be responsible for managing the isSignedIn as the only components that use this state are the NavBar and Login components. With that said, consider using Pinia to manage the states between components.