The goal of this tutorial is to help you understand the 'context' object in Nuxt.js middleware. Middleware in Nuxt.js allows you to define custom functions that can run before rendering either a page or a group of pages. The 'context' object is a powerful feature that provides access to key aspects of your application.
By the end of this tutorial, you will:
Prerequisites:
In Nuxt.js, middleware receives the context as the first argument. The context is a special object that contains a lot of useful properties and methods, such as params
, query
, req
, res
, store
, redirect
, etc.
export default function (context) {
// Use context
}
Context is available in several places:
* In data
and fetch
method
* On the server-side in asyncData
and nuxtServerInit
* In middleware
Here are some practical examples to help you understand the context object:
Example 1: Accessing route params in middleware
// middleware/checkParams.js
export default function (context) {
// access route params
const { params } = context
console.log(params) // { id: '1' }
}
In this example, we create a middleware function checkParams
that logs the route parameters. If we navigate to a route like /post/1
, the console will output { id: '1' }
.
Example 2: Using redirect method
// middleware/redirect.js
export default function (context) {
// use redirect method
if (!context.store.state.authenticated) {
context.redirect('/login')
}
}
In this example, we check if the user is authenticated. If not, we use the redirect
method from the context object to navigate the user to the login page.
In this tutorial, we've covered:
Next steps:
asyncData
and nuxtServerInit
Additional resources:
Exercise 1: Create a middleware function that logs the query parameters of the current route.
Solution:
// middleware/logQuery.js
export default function (context) {
// log query parameters
console.log(context.query)
}
Exercise 2: Create a middleware function that checks if a user is an admin. If not, redirect them to a '/no-access' page.
Solution:
// middleware/checkAdmin.js
export default function (context) {
// check if user is an admin
if (context.store.state.user.role !== 'admin') {
context.redirect('/no-access')
}
}
These exercises should give you some practical experience with using the context object in Nuxt.js middleware. Keep practicing to improve your understanding.