What are the best practices for using router guards in Vue 3?

What are the best practices for using router guards in Vue 3?

When using router guards in Vue 3, it's important to keep your logic clean and maintainable. Here are some best practices:

1. Use Navigation Guards Wisely: Apply guards only where necessary to avoid performance issues.
2. Centralize Logic: Consider centralizing your authentication logic in a single file to keep your routes clean.
3. Use Async Guards: Take advantage of async router guards to handle asynchronous operations like API calls.
4. Error Handling: Implement error handling within your guards to manage failed navigation gracefully.
5. Keep Guards Simple: Avoid complex logic in guards; instead, delegate to services or store actions.

Can you explain how to implement an async router guard?

Sure! To implement an async router guard in Vue 3, you can return a Promise from your guard function. Here's a simple example:

const router = createRouter({
  history: createWebHistory(),
  routes: [
    {
      path: '/protected',
      component: ProtectedComponent,
      beforeEnter: async (to, from, next) => {
        const isAuthenticated = await checkAuthentication();
        if (isAuthenticated) {
          next(); // Allow navigation
        } else {
          next('/login'); // Redirect to login
        }
      }
    }
  ]
});

In this example, checkAuthentication is an async function that checks if the user is authenticated.

What should I do if a guard fails?

If a guard fails, you should handle the failure gracefully. You can redirect the user to a different route, show an error message, or log the error for debugging. For example, in your guard, you can use the next function to redirect:

beforeEnter: async (to, from, next) => {
  try {
    const isAuthenticated = await checkAuthentication();
    if (isAuthenticated) {
      next();
    } else {
      next('/login');
    }
  } catch (error) {
    console.error('Guard failed:', error);
    next('/error'); // Redirect to an error page
  }
}

Are there any performance considerations I should be aware of?

Yes, performance is crucial when using router guards. Here are a few considerations:

1. Minimize Logic: Keep the logic in your guards minimal to avoid slowing down navigation.
2. Avoid Heavy Computations: Don't perform heavy computations or synchronous operations in guards.
3. Batch API Calls: If you need to make multiple API calls, try to batch them to reduce the number of requests.
4. Use Caching: Cache results of authentication checks or other data to avoid repeated calls.