Next.js 14 Tutorial - 9 - Catch all Segments

Summary

In this video, the concept of 'catch-all segments' in Next.js routing is explained. The instructor walks through building a documentation site, showcasing how to dynamically reduce the number of route files using catch-all segments. By creating a single file that handles multiple route segments, the video demonstrates a more efficient folder structure and improved URL handling. The video also covers how to access different URL segments through the `params` object and introduces optional catch-all routes to handle undefined paths. This approach is particularly useful for SEO and organization in large documentation projects.

Takeaways

• 😀 Catch-all segments allow handling multiple routes with a single file.
• 📁 Dynamic routing reduces the need for hundreds of individual route files by using feature and concept ID folders.
• 📚 A documentation site with many features and concepts can quickly grow into a complex folder structure, but dynamic routing simplifies it.
• 🔀 Using the `...slug` format in Next.js, you can match all routes that include specific path segments, like `docs`.
• 🌐 The `slug` array captures URL segments, allowing flexible handling of different routes.
• 📝 The catch-all page file in the `slug` folder returns an H1 tag and text based on the captured route segments.
• 🔍 Conditional logic can be used to check the length of the `slug` array and display different content depending on the route depth.
• ⚙️ Catch-all segments are especially useful for documentation websites where layout consistency is important across many routes.
• ❓ Next.js also supports optional catch-all segments to prevent 404 errors when fewer URL segments are provided.
• 📄 The catch-all segment can be used to fetch documentation dynamically for specific feature and concept IDs.

Q & A

What is the purpose of the 'catch all segments' feature in Next.js?

The 'catch all segments' feature in Next.js allows you to handle multiple route segments with a single file. It is particularly useful for scenarios where you need to manage many dynamic paths, such as a documentation site with various features and concepts, without creating a large number of files.

How does dynamic routing help reduce the number of files in a Next.js project?

Dynamic routing allows you to replace specific files with dynamic route folders using IDs, such as feature ID and concept ID. This approach reduces the number of files by consolidating them into fewer folders, making the folder structure more efficient and manageable.

What is the benefit of using a 'slug' for URL segments in a Next.js application?

Using a 'slug' for URL segments provides a flexible way to capture and manage multiple route parameters. It simplifies the routing system and allows the same layout to be applied across different URL variations, improving both organization and SEO.

How can you access the route parameters in the 'catch all segments' route?

You can access the route parameters using the 'params' object, which is provided by Next.js. The 'slug' will be an array of strings that you can use to determine the specific feature or concept being viewed based on the length and content of the URL segments.

What happens if there are no route parameters in the 'catch all segments' route?

If there are no route parameters, the default view for the 'docs' page will be displayed. This is handled by checking the length of the 'slug' array and returning the appropriate UI content, such as a generic 'Docs homepage' message.

What is the purpose of using optional chaining in the code example?

Optional chaining is used to prevent errors when accessing properties that may be undefined. In the example, it ensures that the code can safely handle cases where there are missing route parameters without crashing.

What happens when you navigate to a URL that only includes '/docs' without any additional segments?

By default, Next.js will display a 404 error page when navigating to '/docs' without additional segments. However, by using an optional catch all route (double square brackets around the 'slug'), you can render the same page for '/docs' without showing an error.

Why is a catch-all route useful for documentation websites?

A catch-all route is useful for documentation websites because it allows the layout and structure of the documentation to remain consistent across different features and concepts, while still providing unique content based on the URL segments. This reduces the complexity of the routing system and improves maintainability.

How does Next.js determine which part of the URL matches a catch-all segment?

Next.js uses the '...' notation in the file name to match all segments after a specified path. For example, a file named '[...slug].tsx' in the 'docs' folder will capture any path that includes '/docs' followed by additional segments and map it to the same file.

What would happen if you added another level of nesting to the route structure?

If you add another level of nesting, each additional path segment in the URL would require a corresponding level of folder nesting in the project. However, using the catch-all segments feature simplifies this by capturing all segments with a single file, preventing deep folder structures.

Outlines

00:00

📚 Introduction to Catch-All Segments in Routing

The video introduces the concept of 'catch-all segments' in routing using a documentation site example. The scenario involves building a documentation site for a project with multiple features and concepts, leading to hundreds of potential routes. The speaker explains that instead of creating 400 files for these routes, dynamic routing with Next.js allows reducing the number of files by using dynamic route folders, one for 'feature' and one for 'concept'. While this improves the folder structure, additional URL paths would require more folder nesting. The solution is to define one file to handle all route segments using Next.js's catch-all segments feature.

05:01

🚀 Setting Up the Catch-All Segments

The speaker explains how to implement catch-all segments using Next.js. In the app folder, a folder named 'docs' is created, and within it, a special folder with square brackets and three dots (similar to JavaScript's spread operator) is named 'slug'. This dynamic folder will handle all URLs with the 'docs' segment. A basic React component is added to the file inside this folder. When navigating to various URLs like 'docs/feature1/concept1', the same page is displayed, demonstrating that the catch-all route captures all URL segments and maps them to this single file, improving the organization and SEO of the documentation site.

Keywords

💡Catch-all segments

Catch-all segments refer to a routing mechanism in Next.js that allows developers to match any URL that includes a specific segment in the path. In the video, this concept is central, as it explains how catch-all segments can simplify routing by capturing all possible URL variations and mapping them to a single file. This is particularly useful when dealing with many routes, as it reduces the number of necessary files and folders.

💡Dynamic routing

Dynamic routing is the process of using parameters in URLs to dynamically load different content or components. In the video, dynamic routing is suggested as a solution to avoid creating hundreds of files for different routes by using dynamic segments like 'concept ID' and 'feature ID'. This simplifies the folder structure and enables more efficient routing.

💡Slug

A 'slug' in web development refers to the part of a URL that identifies a particular page. In the context of Next.js, the video uses the term 'slug' to describe a dynamic folder name that captures URL segments. By naming the folder '[...slug]', it allows the app to catch all segments of the URL and map them to a single route.

💡File system-based routing

Next.js uses a file system-based routing system where the folder and file structure in the project directory mirrors the URL structure of the site. The video highlights this concept by explaining how creating separate files for each route would result in 400 files, but by leveraging dynamic routes, this can be reduced significantly.

💡Routing

Routing refers to the process of determining which content to display based on the URL structure. In the video, routing is the main theme, and the speaker explains various methods to handle complex URL structures, particularly in documentation sites where there are multiple features and concepts that need to be organized.

💡Docs folder

The 'docs' folder is a directory used in this example to handle documentation-related routes. The video explains how a folder named 'docs' is created in the app directory, and within it, a special catch-all folder is added to handle all routes containing 'docs' in the URL. This setup allows for flexible documentation routing.

💡Feature ID

Feature ID is a dynamic parameter used in the URL to represent a specific feature in the documentation. The video explains how replacing static feature folders with dynamic 'feature ID' folders reduces the number of files, as each feature can be represented by an ID instead of having a separate folder for every individual feature.

💡Concept ID

Concept ID is another dynamic parameter representing a specific concept within a feature. The video describes how organizing routes based on 'concept ID' allows for the reduction of folders, while still enabling the app to handle multiple concepts within a feature without creating additional files for each concept.

💡Optional catch-all route

An optional catch-all route in Next.js is a feature that handles paths where segments may or may not be present. The video demonstrates how wrapping the square brackets with an additional set of brackets makes the catch-all route optional, ensuring that the app does not throw a 404 error if a path like '/docs' is visited without further segments.

💡Params object

The params object refers to an object that contains the URL parameters. In the video, the speaker explains how Next.js provides this object to access the dynamic parameters captured by the catch-all segment. By using this object, developers can extract values like 'feature ID' and 'concept ID' from the URL to display the corresponding content.

Highlights

Introduction of catch-all segments in Next.js routing.

Scenario: Building a documentation site with multiple features and concepts.

Dynamic routing reduces 400 routes to just 2 folders by using feature ID and concept ID.

Catch-all segments allow for a single file to handle multiple routes with the same layout.

Folder structure optimization: using `[...]slug` to capture all segments under 'docs' folder.

React component example: Creating a page in `docs` folder that handles multiple URL segments.

Any URL containing 'docs' will map to a single `page.tsx` file, demonstrating routing efficiency.

The advantage of catch-all segments for documentation websites is better organization and SEO.

Slug array allows access to different route segments dynamically using the `params` object.

Conditional rendering in JSX: Differentiating between feature-only routes and feature-concept routes.

Navigation examples: `/docs/feature1/concept1` dynamically renders corresponding page content.

The optional catch-all route feature in Next.js prevents 404 errors for incomplete routes.

Use of optional chaining to handle undefined values in the route segments.

The catch-all segments approach simplifies routing and reduces nesting complexity in the folder structure.

Visualization of catch-all segments: root routes and how `docs/[...slug]` matches any path with 'docs'.

Transcripts

welcome back everyone in this video we

will learn yet another routing concept

called catch all segments to understand

this concept let's consider scenario

number six let's assume we are building

a documentation site for a project that

we have created the site contains

several features and each feature

consists of multiple Concepts that need

to be explained so let's assume our snav

looks like this we have five features

and the first feature is expanded to

display five

Concepts our goal is to have a unique

route for each concept under a given

feature for

example Local Host 3000 do/ feature 1/

concept 1 docs feature 1 concept 2 docs

feature 2 concept one docs feature 2

concept 2 and so

on considering we may have 20 features

and each feature may have 20 Concepts we

end up with a massive 400 routes for our

application and now that you know nexs

has a file system based routing

mechanism 400 routes correspond to 400

files in our

project but of course we can make use of

dynamic routing by replacing the concept

files with Dynamic route folders using a

concept ID we can reduce the number of

files to 20 similarly if we replace the

feature folder with a dynamic feature ID

folder name we left with only two

folders the concept ID folder nested

inside the feature ID

folder this approach significantly

improves the folder

structure however we need to keep in

mind that for each additional path in

the URL we will require another level of

nesting in our app folder for example

docs SL feature 1/ concept cep one/

example one would lead to another level

of

nesting considering that every page in

our documentation website shares the

same layout wouldn't it be great if we

could Define one file that could handle

all the route segments in the

URL well with next sh we can achieve

that using the catch all segments

feature let's dive into vs code and

understand how it

works in the app folder

create a new folder called

docs within this folder create another

folder the folder name is special to

next shares inside square brackets use

three dots similar to the spread

operator in JavaScript and provide a

name of your choice in this case let's

call it slug which is a common

convention when referring to

URLs inside this folder create create a

page. TSX

file and add a basic react

component the component name is

docs and we return an H1 tag docs home

page what makes this file special is

that it will match any URL that contains

the docs segment in the path let me Demo

this in the

browser if I type localhost 3000 SL docs

SL feature

1 we see the docs page navigating to

docs SL feature

oneconcept

one or slash example

one also displays the same page as the

name suggests the catchall segments

route captures all URL segments and Maps

them to this single file in our

project this is particularly useful for

documentation where we want different

segments for better organization and SEO

but the layout of the document Remains

the Same we Define it once but render it

for multiple variations of the

URL of course this feature is only

useful if we can access the different

segments in the URL let me show you how

to achieve that once again we rely on

the params object provided by ni

shares D structure it from

props and specify the

type this time slug is an array of

string we can have multiple route

parameters for the jsx we will use an if

else block to handle the different

possibilities if params do slug do lens

is equal to two we return an H1 tag that

says viewing docs for feature harams do

slug of zero since feature ID is the

first route

parameter and concept params do slug of

one else if params do slug do length is

equal to

1 we return an H1

tag viewing docs for

feature parms do slug of

zero if there are no route parameters

and slug length is zero we return talks

homepage as the text in the

browser navigate to/ dos SL

routing and we see the text viewing Docs

for feature routing navigate to SL doogs

SL routing SL catchall

segments and we see the text viewing

docs for feature routing and concept

catch all segments the UI logic can be

customized according to your needs

depending on how you want to handle the

different route segments ideally you

would use the slug array to fetch the

corresponding documentation for the

feature ID and concept ID scenario 6 has

been successfully

implemented lastly I want to mention

that nexs provides an optional catch all

route as well currently if I navigate to

just SL

docs we see a 404 error page this is

taken care of by NYX Shar however if you

want to display the same Doc Page next

just provides optional catchall segments

all you have to do is wrap the square

brackets with another pair of square

brackets now we do have an error cannot

read properties of

undefined so let's add optional

chaining if we head back to the browser

you would see that the same catch all

segments page is rendered for just SL

docs as

well the last return statement is

executed in this

case here is a visualization of catchall

segments we have the root route and any

path that contains the docs segment will

be matched by the page. TSX file within

the slug catchall

segment all right we have covered quite

a bit about next year's routing but we

still have a long way to go we will

explore the remaining features in the

upcoming videos thank you for watching

and I'll see you in the next one