Defining routes in Vue

Introduction

Routes help your app show different pages when users click links or enter URLs. They make your app feel like a website with many pages.

You want to show a homepage and an about page in your app.

You need to let users visit different sections like profile, settings, or dashboard.

You want to change the displayed content without reloading the whole page.

You want to handle URLs so users can bookmark or share specific pages.

You want to show a 'not found' page when users enter a wrong URL.

Syntax

Vue

import { createRouter, createWebHistory } from 'vue-router'

const routes = [
  { path: '/', component: Home },
  { path: '/about', component: About }
]

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

export default router

The routes array lists all pages with their URL paths and components.

createRouter sets up the router with history mode and routes.

Examples

Defines two routes: homepage and contact page.

Vue

const routes = [
  { path: '/', component: Home },
  { path: '/contact', component: Contact }
]

Route with a dynamic segment :id to show different user profiles.

Vue

const routes = [
  { path: '/user/:id', component: UserProfile }
]

Catch-all route to show a 'not found' page for unknown URLs.

Vue

const routes = [
  { path: '/:pathMatch(.*)*', component: NotFound }
]

Sample Program

This Vue app shows a home page at '/' and an about page at '/about'. The router changes the displayed page without reloading.

Vue

import { createApp } from 'vue'
import { createRouter, createWebHistory } from 'vue-router'

const Home = { template: '<h1>Home Page</h1>' }
const About = { template: '<h1>About Page</h1>' }

const routes = [
  { path: '/', component: Home },
  { path: '/about', component: About }
]

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

const app = createApp({})
app.use(router)
app.mount('#app')

Important Notes

Always import and use the router in your main Vue app to enable routing.

Use router-link components to create accessible links between routes.

Test routes in the browser by typing URLs or clicking links to see pages change.

Summary

Routes connect URLs to components to show different pages.

Define routes in an array with path and component.

Use createRouter and createWebHistory to set up routing.

Practice

1. What is the main purpose of defining routes in a Vue application?

easy

A. To style components with CSS

B. To connect URLs to components so different pages can be shown

C. To manage state between components

D. To handle user input events

Solution

1. Step 1: Understand the role of routes

   Routes link specific URLs to Vue components, allowing navigation between pages.

2. Step 2: Identify the correct purpose

   Connecting URLs to components matches the description of routing.

3. Final Answer:

   To connect URLs to components so different pages can be shown -> Option B

4. Quick Check:

   Routes = URL to component mapping [OK]

Hint: Routes map URLs to components for page navigation [OK]

Common Mistakes:

• Confusing routes with styling or CSS
• Thinking routes manage state or events
• Mixing routes with user input handling

2. Which of the following is the correct way to define a route for path '/home' using a component named HomeView?

easy

A. { path: '/home', component: HomeView }

B. { route: '/home', view: HomeView }

C. { url: '/home', component: HomeView }

D. { path: '/home', view: HomeView }

Solution

1. Step 1: Recall route object keys

   Routes use keys 'path' for URL and 'component' for the Vue component.

2. Step 2: Match correct syntax

   { path: '/home', component: HomeView } uses correct keys: path and component with proper values.

3. Final Answer:

   { path: '/home', component: HomeView } -> Option A

4. Quick Check:

   Route keys = path + component [OK]

Hint: Use 'path' and 'component' keys to define routes [OK]

Common Mistakes:

• Using 'route' or 'url' instead of 'path'
• Using 'view' instead of 'component'
• Mixing keys or misspelling them

3. Given this route setup:

const routes = [
  { path: '/', component: HomeView },
  { path: '/about', component: AboutView }
];
const router = createRouter({
  history: createWebHistory(),
  routes
});

What component will show when the URL is '/about'?

medium

A. AboutView

B. HomeView

C. createRouter

D. createWebHistory

Solution

1. Step 1: Check the route matching '/about'

   The route with path '/about' uses component AboutView.

2. Step 2: Understand router behavior

   When URL is '/about', Vue Router renders AboutView component.

3. Final Answer:

   AboutView -> Option A

4. Quick Check:

   URL '/about' shows AboutView [OK]

Hint: URL matches route path to show its component [OK]

Common Mistakes:

• Confusing router functions with components
• Choosing HomeView for '/about' URL
• Not linking URL to correct route

4. Identify the error in this route definition:

const routes = [
  { path: '/contact', component ContactView }
];

medium

A. Component name should be a string

B. Path should start with '#' instead of '/'

C. Missing colon ':' after 'component'

D. Routes array should be inside createRouter

Solution

1. Step 1: Check object syntax in route

   Each key-value pair must have a colon ':' separating them.

2. Step 2: Spot missing colon after 'component'

   In the route, 'component ContactView' misses ':'; it should be 'component: ContactView'.

3. Final Answer:

   Missing colon ':' after 'component' -> Option C

4. Quick Check:

   Object syntax needs ':' [OK]

Hint: Check colons between keys and values in objects [OK]

Common Mistakes:

• Forgetting colon ':' in object properties
• Using '#' instead of '/' in paths
• Putting component names as strings incorrectly

5. You want to create a Vue router with two routes: '/' showing HomeView and '/profile/:id' showing ProfileView. Which code correctly defines these routes and sets up the router?

hard

A. const routes = [
{ path: '/', component: HomeView },
{ path: '/profile/:id', component: ProfileView }
];
const router = createRouter({
history: createMemoryHistory(),
routes
});

B. const routes = [
{ path: '/', component: HomeView },
{ path: '/profile/id', component: ProfileView }
];
const router = createRouter({
history: createWebHistory(),
routes
});

C. const routes = [
{ path: '/', component: HomeView },
{ path: '/profile/:id', component: 'ProfileView' }
];
const router = createRouter({
history: createWebHistory(),
routes
});

D. const routes = [
{ path: '/', component: HomeView },
{ path: '/profile/:id', component: ProfileView }
];
const router = createRouter({
history: createWebHistory(),
routes
});

Solution

1. Step 1: Define routes with dynamic segment

   Use '/profile/:id' to capture dynamic id parameter correctly.

2. Step 2: Use correct component references and history mode

   Components must be variables (not strings). Use createWebHistory() for normal web routing.

3. Step 3: Check each option

   const routes = [ { path: '/', component: HomeView }, { path: '/profile/:id', component: ProfileView } ]; const router = createRouter({ history: createWebHistory(), routes }); matches all requirements: dynamic path, component variables, and web history.

4. Final Answer:

   Correct route array with dynamic segment and createWebHistory() -> Option D

5. Quick Check:

   Dynamic routes use ':param' and createWebHistory() [OK]

Hint: Use ':param' for dynamic routes and createWebHistory() for browser routing [OK]

Common Mistakes:

• Using literal 'id' instead of ':id' for dynamic segments
• Passing component names as strings instead of variables
• Using createMemoryHistory() instead of createWebHistory() for web apps