Vue3 Middleware

vue3-middleware is a lightweight plugin for Vue 3 applications that provides middleware functionality. It allows you to add middleware functions that runs before each navigation, providing a powerful tool for handling authentication, authorization, logging, and other concerns. With just a few simple steps, you can add this plugin to your vue application.

Installation

You can install vue3-middleware using npm or yarn.

Please note that this plugin currently support only vue 3.x and vue-router 4.x

# install using npm
npm install vue3-middleware

# or with yarn
yarn add vue3-middleware

Usage

Setting Up Middleware

First, you need to set up the middleware in your Vue 3 application. Import createMiddleware from vue3-middleware and set it up in your main application file (typically main.js or main.ts).

Note: Registered global middlewares will run for every navigation.

import { createApp } from "vue";
import App from './App.vue';
import { createMiddleware } from "vue3-middleware";
import removeTrailingSlash from './middlewares/removeTrailingSlash';
import router from './router';

const app = createApp(App);
const middleware = createMiddleware();

// OR with options
// const middleware = createMiddleware({
//     globalMiddlewares: [
//         removeTrailingSlash
//     ],
//     // OR
//     // globalMiddlewares: removeTrailingSlash
// });

// Registration here
app.use(middleware);

// OR register with options
// app.use(middleware, {
//     globalMiddlewares: [
//         removeTrailingSlash
//     ],
//     // OR
//     // globalMiddlewares: removeTrailingSlash
// });

// Use middleware with the router
app.use(router);

app.mount('#app');

Defining Middleware

You can define middleware functions that will be executed before route changes. Middleware functions receive the to, from, next, cancel and redirect parameters, similar to Vue Router navigation guards.

// middleware/auth.ts
import { useUser } from '@/stores/user.ts';
import type { MiddlewareContext } from 'vue3-middleware';

export default function auth({ to, next, redirect }: MiddlewareContext) {
    const user = useUser();
    if (to.meta.requiresAuth && !user.isLoggedIn) {
        return redirect({ name: 'login' });
    } 
    return next();
}


// middleware/guest.ts
import { useUser } from '@/stores/user.ts';
import type { MiddlewareContext } from 'vue3-middleware';

export default function guest({ from, next, redirect }: MiddlewareContext) {
    const user = useUser();
    if (user.isLoggedIn) {
        return redirect(from);
    } 
    return next();
}


// middleware/removeTrailingSlash.ts
import { useUser } from '@/stores/user.ts';
import type { MiddlewareContext } from 'vue3-middleware';

export default function removeTrailingSlash({ to, next, redirect }: MiddlewareContext) {
    if (to.path.length > 1 && to.path.endsWith("/")) {
        return redirect(to.path.substring(0, to.path.length - 1));
    }
    return next();
}


// middleware/noLeaveNoTransfer.ts
import { useUser } from '@/stores/user.ts';
import type { MiddlewareContext } from 'vue3-middleware';

export default function noLeaveNoTransfer({ cancel }: MiddlewareContext) {
    // Explicitly cancel the navigation and terminate
    return cancel();
}

Applying Middleware to Routes

You can apply middleware to specific routes by using the meta property in your route definitions.

import { createRouter, createWebHistory } from 'vue-router';
import Home from './views/Home.vue';
import Login from './views/Login.vue';
import auth from './middleware/auth';
import guest from './middlewares/guest';
import admin from './middlewares/admin';

const routes = [
    {
        path: '/',
        name: 'home',
        component: Home
    },
    {
        path: '/login',
        name: 'login',
        component: Login,
        meta: {
            middlewares: [guest],
            // OR
            // middlewares: guest
        }
    },
    {
        path: '/dashboard',
        name: 'dashboard',
        component: () => import('./views/Dashboard.vue'),
        meta: {
            middlewares: [auth]
        }
    },
    {
        path: '/admin',
        name: 'admin',
        redirect: {name: 'admin.dashboard'},
        meta: {
            middlewares: [auth, admin]
        }, 
        children: [
            {
                path: 'dashboard',
                name: 'admin.dashboard',
                component: () => import('./views/admin/Dashboard.vue'),
            },
            {
                path: 'users',
                name: 'admin.users',
                component: () => import('./views/admin/Users.vue'),
            }
        ]
    }
];

const router = createRouter({
    history: createWebHistory(),
    routes
});

export default router;

Note: A middleware that's defined on parent route will also guard children routes, so no you don't have to define it again on the children routes.

Example

Here's a full example that combines the setup, middleware definition, and route application.

// main.ts
import { createApp } from "vue";
import App from './App.vue';
import { createMiddleware } from "vue3-middleware";
import removeTrailingSlash from './middlewares/removeTrailingSlash';
import router from './router';

const app = createApp(App);
const middleware = createMiddleware();

app.use(middleware, {
    globalMiddlewares: [
        removeTrailingSlash
    ],
});

app.use(router);
app.mount('#app')


// middleware/auth.ts
import { useUser } from '@/stores/user.ts';
import type { MiddlewareContext } from 'vue3-middleware';

export default function auth({ to, next, redirect }: MiddlewareContext) {
    const user = useUser();
    if (to.meta.requiresAuth && !user.isLoggedIn) {
        return redirect({ name: 'login' });
    } 
    return next();
}


// middleware/guest.ts
import { useUser } from '@/stores/user.ts';
import type { MiddlewareContext } from 'vue3-middleware';

export default function guest({ from, next, redirect }: MiddlewareContext) {
    const user = useUser();
    if (user.isLoggedIn) {
        return redirect(from);
    } 
    return next();
}


// middleware/removeTrailingSlash.ts
import { useUser } from '@/stores/user.ts';
import type { MiddlewareContext } from 'vue3-middleware';

export default function removeTrailingSlash({ to, next, redirect }: MiddlewareContext) {
    if (to.path.length > 1 && to.path.endsWith("/")) {
        return redirect(to.path.substring(0, to.path.length - 1));
    }
    return next();
}


// middleware/noLeaveNoTransfer.ts
import { useUser } from '@/stores/user.ts';
import type { MiddlewareContext } from 'vue3-middleware';

export default function noLeaveNoTransfer({ cancel }: MiddlewareContext) {
    return cancel();
}


// router/index.ts
import { createRouter, createWebHistory } from 'vue-router';
import Home from './views/Home.vue';
import Login from './views/Login.vue';
import auth from './middleware/auth';
import guest from './middlewares/guest';
import admin from './middlewares/admin';

const routes = [
    {
        path: '/',
        name: 'home',
        component: Home
    },
    {
        path: '/login',
        name: 'login',
        component: Login,
        meta: {
            middlewares: [guest],
        }
    },
    {
        path: '/dashboard',
        name: 'dashboard',
        component: () => import('./views/Dashboard.vue'),
        meta: {
            middlewares: [auth]
        }
    },
    {
        path: '/admin',
        name: 'admin',
        redirect: {name: 'admin.dashboard'},
        meta: {
            middlewares: [auth, admin]
        }, 
        children: [
            {
                path: 'dashboard',
                name: 'admin.dashboard',
                component: () => import('./views/admin/Dashboard.vue'),
            },
            {
                path: 'users',
                name: 'admin.users',
                component: () => import('./views/admin/Users.vue'),
            }
        ]
    }
];

const router = createRouter({
    history: createWebHistory(),
    routes
});

export default router;

Contributing

Contributions are welcome! Please feel free to fork this package and contribute by submitting a pull request to enhance the functionalities.

How can I thank you?

Why not star the github repo? I'd love the attention! Why not share the link for this repository on X (formerly Twitter) or HackerNews? Spread the word!

Don't forget to follow me on X (formerly Twitter)! and also follow me on LinkedIn!

Thanks! Jacob Eke.

License

The MIT License (MIT). Please see License File for more information.