Shallow routing concept in NextJS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to enable shallow routing when changing the URL without a full page reload.

NextJS

router.push('/about', undefined, { [1]: true })

Drag options to blanks, or click blank then click option'

Areload

Bshallow

Creplace

Dscroll

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'reload' instead of 'shallow' causes a full page reload.

Forgetting to set the third argument as an object.

Setting shallow: true tells Next.js to change the URL without running data fetching methods again, enabling shallow routing.

2fill in blank

medium

Complete the code to listen for route changes and detect if shallow routing was used.

NextJS

router.events.on('routeChangeComplete', (url, [1]) => { if (shallow) { console.log('Shallow routing!'); } })

Drag options to blanks, or click blank then click option'

Ashallow

Bevent

Croute

Dpath

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong parameter name causes the shallow check to fail.

Ignoring the second argument and missing shallow routing detection.

The second argument to the event callback is a boolean named shallow indicating if shallow routing was used.

3fill in blank

hard

Fix the error in the code to correctly use shallow routing with router.replace.

NextJS

router.replace('/profile', undefined, [1])

Drag options to blanks, or click blank then click option'

A{ shallow: false }

Btrue

C{ shallow: true }

Dfalse

Attempts:

3 left

💡 Hint

Common Mistakes

Passing a boolean directly instead of an object.

Setting shallow to false disables shallow routing.

The third argument must be an object with shallow: true to enable shallow routing with replace.

4fill in blank

hard

Fill both blanks to update the URL with shallow routing and prevent scrolling to top.

NextJS

router.push('/dashboard', undefined, { [1]: true, [2]: false })

Drag options to blanks, or click blank then click option'

Ashallow

Bscroll

Creplace

Dreload

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing 'replace' with 'shallow'.

Forgetting to set scroll to false to keep scroll position.

Use shallow: true to enable shallow routing and scroll: false to prevent scrolling to the top after navigation.

5fill in blank

hard

Fill all three blanks to create a shallow route change with replace, no scroll, and log when shallow routing occurs.

NextJS

router.replace('/settings', undefined, { [1]: true, [2]: false });
router.events.on('routeChangeComplete', (url, [3]) => { if (shallow) console.log('Shallow route changed to', url); });

Drag options to blanks, or click blank then click option'

Ashallow

Bscroll

Dreload

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'reload' instead of 'shallow' disables shallow routing.

Not handling the shallow parameter in the event listener.

Set shallow: true and scroll: false in the replace options, and use shallow as the event callback parameter to detect shallow routing.

Practice

1. What does shallow routing in Next.js primarily do?

easy

A. Reloads the entire page to fetch new data

B. Prevents URL changes when navigating

C. Changes the URL without reloading the page or losing component state

D. Forces a full server-side render on every navigation

Solution

1. Step 1: Understand shallow routing purpose

   Shallow routing updates the URL but keeps the current page component and state intact without a full reload.

2. Step 2: Compare options with shallow routing behavior

   Only Changes the URL without reloading the page or losing component state describes changing the URL without reloading or losing state, matching shallow routing.

3. Final Answer:

   Changes the URL without reloading the page or losing component state -> Option C

4. Quick Check:

   Shallow routing = URL change without reload [OK]

Hint: Shallow routing changes URL but keeps page state [OK]

Common Mistakes:

• Thinking shallow routing reloads the page
• Assuming shallow routing blocks URL changes
• Confusing shallow routing with full page reload

2. Which is the correct way to enable shallow routing using Next.js router's push method?

easy

A. router.push('/page?tab=1', undefined, { shallow: true })

B. router.push('/page?tab=1', { shallow: true })

C. router.push('/page?tab=1', true)

D. router.push('/page?tab=1', { reload: false })

Solution

1. Step 1: Recall router.push syntax for shallow routing

   The third argument to router.push is an options object where shallow: true enables shallow routing.

2. Step 2: Match options with correct syntax

   router.push('/page?tab=1', undefined, { shallow: true }) correctly passes { shallow: true } as the third argument; others are incorrect or incomplete.

3. Final Answer:

   router.push('/page?tab=1', undefined, { shallow: true }) -> Option A

4. Quick Check:

   Shallow routing option is third argument object [OK]

Hint: Use third argument { shallow: true } in router.push [OK]

Common Mistakes:

• Passing shallow option as second argument
• Using boolean instead of options object
• Confusing reload option with shallow

3. Given this code snippet in a Next.js page component:

const router = useRouter();

useEffect(() => {
  console.log('Query changed:', router.query.tab);
}, [router.query.tab]);

const changeTab = () => {
  router.push('/dashboard?tab=2', undefined, { shallow: true });
};

changeTab();

What will be logged to the console after changeTab() is called?

medium

A. Query changed: 2

B. Query changed: undefined

C. Nothing is logged because shallow routing blocks query updates

D. An error occurs because shallow routing cannot update query

Solution

1. Step 1: Understand effect dependency on router.query.tab

   The effect runs when router.query.tab changes, logging its value.

2. Step 2: Analyze shallow routing effect on query

   Shallow routing updates the URL and query parameters without full reload, so router.query.tab updates to '2'.

3. Final Answer:

   Query changed: 2 -> Option A

4. Quick Check:

   Shallow routing updates query and triggers effects [OK]

Hint: Shallow routing updates query, triggers effects [OK]

Common Mistakes:

• Assuming shallow routing blocks query updates
• Expecting no console output
• Thinking shallow routing causes errors

4. Consider this Next.js code snippet:

const router = useRouter();

const handleClick = () => {
  router.push('/profile?section=info', undefined, { shallow: true });
  router.push('/profile?section=details');
};

handleClick();

What is the problem with this code regarding shallow routing?

medium

A. No problem; shallow routing applies to both pushes automatically

B. Shallow routing is ignored because it must be the first push

C. Both pushes cause full reloads because shallow routing is not supported

D. The second push overrides shallow routing, causing a full reload

Solution

1. Step 1: Examine the two router.push calls

   The first call uses shallow routing, the second does not and triggers a full reload.

2. Step 2: Understand effect of second push on routing

   The second push overrides the first and causes a full page reload, negating shallow routing.

3. Final Answer:

   The second push overrides shallow routing, causing a full reload -> Option D

4. Quick Check:

   Non-shallow push cancels shallow routing [OK]

Hint: Later push without shallow cancels shallow routing [OK]

Common Mistakes:

• Assuming shallow routing applies to all pushes automatically
• Thinking shallow routing must be first push only
• Ignoring that non-shallow push triggers reload

5. You want to implement tab navigation in a Next.js page using shallow routing to update the URL query without losing component state. Which approach correctly achieves this?

hard

A. Use router.replace without shallow option to update URL and reset state

B. Use router.push with { shallow: true } when changing tabs and listen to router.query to update UI

C. Reload the page on every tab click to fetch fresh data

D. Manually manipulate window.location to change URL without Next.js router

Solution

1. Step 1: Identify shallow routing usage for tab navigation

   Using router.push with { shallow: true } updates URL query without full reload, preserving component state.

2. Step 2: Confirm UI updates from router.query changes

   Listening to router.query allows UI to react to tab changes smoothly without losing state.

3. Final Answer:

   Use router.push with { shallow: true } and listen to router.query -> Option B

4. Quick Check:

   Shallow routing + query listening = smooth tab navigation [OK]

Hint: Use router.push with shallow and watch router.query [OK]

Common Mistakes:

• Reloading page loses component state
• Using router.replace without shallow resets state
• Manipulating window.location breaks SPA behavior