Navigation guards in Nuxt 3 with defineNuxtRouteMiddleware

Navigation guards in Nuxt 3 are a critical feature for controlling access to application routes, enhancing both security and user experience by ensuring only authorized users can reach certain pages. These guards are implemented using middleware, which runs before a page is rendered, and can be categorized into three types: anonymous, named, and global. Middleware functions, which can be synchronous or asynchronous, take two route objects as arguments to determine navigation flow, using globally available functions like `navigateTo` and `abortNavigation` for redirection or halting navigation. Anonymous middleware is defined directly within a page, while named middleware is created in standalone files, and global middleware applies to all routes without explicit specification. It is crucial to write middleware functions that are lean and free of side effects to avoid performance issues, and care must be taken to prevent creating infinite redirect loops. By following best practices, developers can use navigation guards to effectively manage route access and ensure a smooth user journey across their applications.