Route parameters with useRoute in Vue - Mini Project: Build & Apply

Route parameters with useRoute

📖 Scenario: You are building a simple Vue 3 app that shows details for a product based on the product ID in the URL.

🎯 Goal: Create a Vue component that uses the useRoute function to read the id parameter from the URL and display it on the page.

📋 What You'll Learn

Create a Vue component using the <script setup> syntax

Import and use the useRoute function from vue-router

Access the id parameter from the route params

Display the id value inside the template

Use semantic HTML and ensure accessibility

💡 Why This Matters

🌍 Real World

Many web apps show details for items like products, users, or posts based on the URL. Using route parameters lets you build pages that change content dynamically without reloading.

💼 Career

Understanding how to use route parameters with <code>useRoute</code> is essential for frontend developers working with Vue Router to build dynamic, user-friendly single-page applications.

1

Set up the Vue component skeleton

Create a Vue component file with <template> and <script setup> tags. Inside the template, add a <section> with a heading <h1> that says "Product Details".

Vue

  
    Product Details
    
  



// Your code here

Hint

Start by creating the basic structure of a Vue component with template and script setup tags.

2

Import useRoute and get route params

Inside the <script setup> tag, import useRoute from vue-router. Then create a constant called route and assign it the result of calling useRoute().

Vue

  
    Product Details
  



// Import useRoute and create route constant
// Your code here

Hint

Use import { useRoute } from 'vue-router' and then call useRoute() to get the current route object.

3

Extract the id parameter from route params

Create a constant called productId and assign it the value of route.params.id.

Vue

  
    Product Details
  



import { useRoute } from 'vue-router'

const route = useRoute()

// Extract productId from route params
// Your code here

Hint

Access the id property inside route.params and assign it to productId.

4

Display the productId in the template

Inside the <section> tag, below the heading, add a paragraph <p> that shows the text "Product ID: " followed by the value of productId using Vue's mustache syntax.

Vue

  
    Product Details
    
  



import { useRoute } from 'vue-router'

const route = useRoute()
const productId = route.params.id

Hint

Use {{ productId }} inside a paragraph to show the product ID dynamically.

Practice

1. What does the useRoute function in Vue Router allow you to do inside a component?

easy

A. Access the current route's parameters and information

B. Change the URL path programmatically

C. Register a new route dynamically

D. Navigate to a different route without reloading

Solution

1. Step 1: Understand the purpose of useRoute

   useRoute is a Vue Router composable that provides access to the current route object inside a component.

2. Step 2: Identify what can be accessed with useRoute

   It allows reading route parameters, query, name, and path but does not change routes or register them.

3. Final Answer:

   Access the current route's parameters and information -> Option A

4. Quick Check:

   useRoute reads route info = B [OK]

Hint: useRoute reads route info, doesn't change or register routes [OK]

Common Mistakes:

• Thinking useRoute changes routes
• Confusing useRoute with useRouter
• Assuming useRoute registers routes

2. Which of the following is the correct way to import and use useRoute in a Vue 3 component's setup() function?

easy

A. import { useRoute } from 'vue-router'; const route = useRoute(route);

B. import useRoute from 'vue-router'; const route = useRoute();

C. import { useRoute } from 'vue-router'; const route = useRoute();

D. import { useRoute } from 'vue'; const route = useRoute();

Solution

1. Step 1: Check the import source

   useRoute is exported from 'vue-router', so import must be from 'vue-router'.

2. Step 2: Verify usage syntax

   The correct usage is calling useRoute() without arguments to get the current route object.

3. Final Answer:

   import { useRoute } from 'vue-router'; const route = useRoute(); -> Option C

4. Quick Check:

   Correct import and call = D [OK]

Hint: Import from 'vue-router' and call useRoute() with no arguments [OK]

Common Mistakes:

• Importing from 'vue' instead of 'vue-router'
• Calling useRoute with arguments
• Using default import instead of named import

3. Given this Vue 3 component code snippet, what will be logged when the URL is /user/42 and the route is defined as /user/:id?

import { useRoute } from 'vue-router';
import { onMounted } from 'vue';

export default {
  setup() {
    const route = useRoute();
    onMounted(() => {
      console.log(route.params.id);
    });
  }
}

medium

A. null

B. undefined

C. user

D. 42

Solution

1. Step 1: Identify the route parameter

   The route is defined as /user/:id, so id is a parameter expected in route.params.

2. Step 2: Check the URL and logged value

   The URL is /user/42, so route.params.id will be "42". The console logs this value on mount.

3. Final Answer:

   42 -> Option D

4. Quick Check:

   route.params.id = "42" [OK]

Hint: Route param matches URL segment after colon :id [OK]

Common Mistakes:

• Expecting param name instead of value
• Confusing params with query
• Logging before route is ready

4. What is the main issue with this Vue 3 component code that tries to react to route parameter changes?

import { useRoute } from 'vue-router';
import { computed } from 'vue';

export default {
  setup() {
    const route = useRoute();
    const userId = computed(() => route.params.id);
    return { userId };
  }
}

The component does not update userId when the route changes.

medium

A. The route object is not reactive, so computed won't update

B. The computed function is missing a dependency array

C. The useRoute hook must be called inside onMounted

D. The userId should be a ref, not computed

Solution

1. Step 1: Understand reactivity of route

   The route object returned by useRoute() is reactive, but its params property is not deeply reactive by default.

2. Step 2: Why computed does not update

   Because route.params is not reactive, the computed property does not track changes, so userId stays the same.

3. Final Answer:

   The route object is not reactive, so computed won't update -> Option A

4. Quick Check:

   Route params not reactive = A [OK]

Hint: Route params are not deeply reactive; watch route.fullPath instead [OK]

Common Mistakes:

• Assuming route.params is reactive
• Calling useRoute inside lifecycle hooks
• Using ref instead of computed incorrectly

5. You want to create a Vue 3 component that displays the user ID from the route parameter and updates automatically when the route changes. Which approach correctly achieves this?

import { useRoute } from 'vue-router';
import { computed, watch, ref } from 'vue';

export default {
  setup() {
    const route = useRoute();
    // What should userId be?
    const userId = ???
    return { userId };
  }
}

hard

A. computed(() => route.params.id)

B. computed(() => route.params.id) with a watch on route.fullPath to trigger updates

C. computed(() => route.fullPath.split('/')[2])

D. ref(route.params.id) without any watcher

Solution

1. Step 1: Understand reactivity limitations

   Route params are not deeply reactive, so computed(() => route.params.id) alone won't update when params change.

2. Step 2: Use a watch on route.fullPath to trigger updates

   Watching route.fullPath (which is reactive) and recomputing userId ensures updates when the route changes.

3. Final Answer:

   computed(() => route.params.id) with a watch on route.fullPath to trigger updates -> Option B

4. Quick Check:

   Watch route.fullPath for param changes = C [OK]

Hint: Watch route.fullPath to react to param changes in computed [OK]

Common Mistakes:

• Using computed alone without watch
• Parsing fullPath manually without reactivity
• Using ref without updating on route change