Middleware in Nuxt.js allows you to define custom functions that can be run before rendering either a specific page or layout. These functions can be used to perform tasks such as authentication and redirecting unauthenticated users, or modifying the data that is used to render a page.
In Nuxt 3, middleware functions are defined in the middleware directory inside the root of your project. Each file in this directory represents a separate middleware function. The name of the file is used as the name of the middleware, and the function exported from the file is executed when the middleware is called.
To apply a middleware to a specific page or layout, you can define it in the middleware property of the page or layout. For example, if you want to apply a middleware called authenticate to a page called about, you would create a file called about.vue in the pages directory, and add the middleware property to the page.
In summary, middleware in Nuxt 3 allows you to define custom functions that can be run before rendering either a specific page or layout. These functions can be used to perform tasks such as authentication and redirecting unauthenticated users, or modifying the data that is used to render a page. You can define your middleware in the middleware directory and apply them to specific pages or layouts or globally.
Guillaume Duhan