NodeJS
Tags: #◇Web Development #◇CCAPDEV #◇NodeJS #◇Code Snippets #◇M4
◇Overview
Extracted notes for NodeJS covering both theoretical and practical elements.
◇Key Definitions
For this lecture: NodeJS Features Creating a Server The Request object The Response object Status Codes URL routing
Let’s do a quick review... on the last few things we have discussed
What is NodeJS? NodeJS is an open-source JavaScript runtime environment JavaScript was originally meant to run only on browsers NodeJS allowed JavaScript to run outside of browsers No need to learn another programming language since it uses JavaScript everywhere
Back to our current lecture... Let’s talk about NodeJS’ features
Features of NodeJS So what can NodeJS even do? with NodeJS's HTTP API, we can... generate dynamic page content create, open, read, write, delete, and close server files collect form data add, delete, modify data in the database
◇Code Implementation
Creating a Server
To create a server, you need to include the http module
A common way to include modules is as follows:
const varName = require('modulename');
varName
constant variable to hold your module
modulename
the name of the module to include
Creating a Server
To create a server, you need to include the http module
A common way to include modules is as follows:
const http = require(‘http');
varName
constant variable to hold your module
modulename
the name of the module to include
Creating a Server
After including the http module, let’s use the http variable to create a server
http.createServer([requestListener]);
.createServer()
method that return the http.Server object
[requestListener]
listens to a port and executes a function each time a request is made to the server
The Request Listener
The requestListener handles requests and responses from the client and back to the client respectively
function (req, res) { }
req
represents an IncomingMessage object containing
details about the client request
res
represents a ServerResponse object, responsible for
the response stream back to the client
Creating a Server
To activate the server, we have to make it listen to a port.
This can be done using server.listen
server.listen([port], [host], [callback]);
port
the port to bind the server into
host
the IP address to bind the server
callback
the function executed after the server has been
bounded
◇Syntax Breakdown
Ensure correct syntax for NodeJS Pay attention to specific functions and declarations.
◇Complexity Analysis
Time Complexity: O(1) for typical operations unless looping. Space Complexity: O(1) generally.
◇References & Navigation
- Previous Topic: ◇Client Server Architecture
- Next Topic: ◇Express
- Related Notes: ◇Client Server Architecture
ACTIVE RECALL VERIFICATION
Select an answer to verify conceptual comprehension and reveal the technical rationale.
Which Node.js module must be required to create a basic web server manually?
What does the req parameter represent in the request listener function function (req, res) { }?
How do you make a Node.js HTTP server start accepting requests?