#11 What is Routing | Fundamentals of NODE JS | A Complete NODE JS Course

Summary

In this lecture, we explored the basics of implementing routing in a Node.js application. We discussed how to handle different URLs using route handlers, allowing the server to respond with specific content such as home, about, or contact pages. The concepts of file-based URLs and resource-based URLs were introduced, highlighting how the latter enables dynamic content generation. We also covered route parameters and query strings for more granular control over requests. In the next lecture, we will implement routing to handle different URLs and provide tailored responses based on user input.

Takeaways

• 😀 In the last lecture, a basic server was set up in a Node.js application using the 'createServer' method to handle incoming requests.
• 😀 The server returns an HTML response for any request, and the URL for the root server is typically 'localhost:8000' or '127.0.0.1:8000'.
• 😀 The root URL is the entry point for a web application, which in real applications would be mapped to a domain like 'www.google.com'.
• 😀 The server currently responds with the same content regardless of what URL path follows the root, such as '/home' or '/about'.
• 😀 Routing is introduced as a technique to provide different responses based on specific URL paths, such as showing the home, about, or contact page.
• 😀 A **file-based URL** directly maps to a specific file on the server, like 'index.html' or 'about.html', which the server returns.
• 😀 A **resource-based URL** uses a URL pattern that is not tied to a specific file but is handled by a request handler function in the backend.
• 😀 Routing helps create dynamic responses for different URL paths, allowing a single server to handle multiple routes and pages.
• 😀 **Route parameters** are dynamic elements in a URL, such as '/product/101', where '101' represents a product ID that can be used to fetch specific data.
• 😀 **Query strings** are additional parameters in a URL, added after a '?' symbol, such as '/books?author=John&ID=101', which provide extra information for processing the request.
• 😀 The server can extract route parameters and query strings to tailor the response based on the specific values passed in the URL.

Q & A

What is the purpose of the server implemented in the lecture?

The server is implemented to return a simple HTML response whenever a new request hits the server. This is done using the `createServer` method in Node.js.

What does the server return when a request is made?

The server returns an HTML response that is stored in a variable called `HTML` within the callback function.

What is the root URL in this application, and how can it be accessed?

The root URL in this application is `localhost:8000` or `127.0.0.1:8000`. It can be accessed by typing this URL in the browser's address bar.

Why does the same HTML response appear regardless of the URL entered after the root?

This happens because the server is not yet implemented with routing, meaning it returns the same response for any URL that follows the root URL.

What is the goal for modifying the current server behavior?

The goal is to implement routing so that different responses (such as Home, About, or Contact pages) are shown based on the URL typed after the root URL.

What does 'routing' mean in the context of web applications?

Routing in web applications refers to the process of handling client requests and returning different responses based on the URL or the parameters specified in the URL.

What are file-based URLs, and how do they differ from resource-based URLs?

File-based URLs map directly to physical files (e.g., `index.html`, `about.html`), while resource-based URLs map to request handlers in the backend, allowing for dynamic responses without directly referencing physical files.

What role do request handlers play in resource-based URLs?

Request handlers are responsible for processing requests made to resource-based URLs and returning the appropriate response, such as dynamic HTML content, rather than static files.

What are route parameters, and how are they used in URLs?

Route parameters are values passed in the URL, such as an ID (e.g., `/product/101`), that allow the server to respond with dynamic content based on those parameters.

How do query strings work in URLs, and how are they useful?

Query strings are key-value pairs added after a `?` in the URL, which can be used to pass additional information to the server, like filtering results or specifying values (e.g., `/books?author=John&ID=101`).

What will the next lecture focus on regarding routing in Node.js?

The next lecture will focus on implementing routing in the Node.js application, allowing it to respond to different URLs with different responses, based on parameters and query strings.