node.js

Prerequisite Python What Is Flask ? Flask is a lightweight Web framework written in Python. It is developed by  Armin Ronacher. Flask is based on the Werkzeug WSGI toolkit and Jinja2 template engine Setup Development Environment First Install Virtualenv In Python virtualenv  is a virtual python environment builder.virtualenv    is used to manage python packages for different projects. Using virtualenv allows you to avoid installing python packages globally which could break system tools or other projects. Install the virtualenv using the following command.This command needs administrator privileges # pip install virtualenv After installing the virtualenv . Make Folder create new folder using the following command  # mkdir flaskdemo change to the current created directory/folder # cd flaskdemo Create a Virtual Environment for Flask In Folder Now we will create a virtualenv .  The commands below will c...

How to Upload Images in Node.js and Express Using AJAX and jQuery Handling asynchronous file uploads without refreshing the page provides a seamless user experience. In this tutorial, we will explore how to upload an image file using AJAX and jQuery in a Node.js and Express application. We will use the browser's FileReader API to read the selected file as a Data URL, send the Base64-encoded payload to the server via AJAX, and save it directly to the server using Node's fs (File System) module. Project Structure Your project directory should be structured as follows: upload/ ├── views/ │ └── demo.ejs ├── app.js └── package.json Step 1: Set Up Your Project Folder Open your command prompt or terminal and initialize a new directory for your project: mkdir upload cd upload Step 2: Initialize Node.js and Install Dependencies Initialize your Node.js environment by creating a package.json f...

Modern web users expect applications to respond instantly—without jarring page reloads or delays. If you want to build fast, reactive web applications, mastering asynchronous data communication is a must. In this comprehensive, step-by-step tutorial, you will learn how to build a dynamic web app using AJAX, Node.js, Express, and MongoDB . We will guide you through creating a full-stack application from scratch using a clean, modular project architecture. You will discover how to connect your Node.js backend to MongoDB via Mongoose models, configure Express routers for asynchronous GET , POST , and DELETE operations, and manipulate the DOM dynamically on the frontend using jQuery AJAX—all without a single page refresh. Project Directory Structure Organize your project files cleanly using the following modular structure: ajax/ ├── models/ │ └── task.js ├── public/ │ └── data.js ├── routes/ │ └── taskroute.js ├── views/ │ └── demo.ejs ├── app.js └── package.json Step 1: ...

Handling bulk data uploads is a frequent requirement in enterprise applications and student record management systems. If you need a reliable way to upload spreadsheet data, parse rows, and store records directly in a database, learning how to process CSV files is essential. In this comprehensive, step-by-step tutorial, you will learn how to import and parse CSV files into MongoDB using Node.js, Express, Multer, and the csvtojson package . We will walk through setting up your project folders, configuring Multer disk storage, converting CSV rows into structured JSON arrays, and rendering records dynamically on an EJS frontend table. Project Structure Organize your project files cleanly with the following architecture: csv/ ├── models/ │ └── csv.js ├── public/ │ └── uploads/ ├── views/ │ └── demo.ejs ├── app.js └── package.json Step 1: Set Up Your Project Folder Open your command prompt or terminal and create your working directory: # Create a new directory and move in...

When building scalable web applications, querying and filtering large datasets directly from the database is essential. Client-side filtering only works for small lists, but as your database grows, you need server-side search . In this tutorial, we will walk through how to build a dynamic search feature in a Node.js application using Express, EJS, Mongoose, and MongoDB's $regex operator . Prerequisites & Tech Stack Make sure you have Node.js and MongoDB installed on your system. We will use the following packages: Express : Fast web framework for handling HTTP requests. Mongoose : Elegant ODM library for MongoDB and Node.js. EJS : Embedded JavaScript templating engine for rendering dynamic views. Body-Parser / Express Urlencoded : For parsing incoming form and query data. Step 1: Set Up the Project Folder Open your terminal or command prompt and run the following commands to create and enter your project directory: mkdir searching cd searching Next, initialize a new No...

Introduction Storing plaintext passwords in a database is one of the most critical security vulnerabilities a web application can have. If a database is compromised, every user account is instantly exposed. To protect user credentials, modern backend applications rely on secure cryptographic hashing functions like bcrypt . In this tutorial, we will walk through how to build a secure user registration and login API in Node.js using Express, Mongoose, and bcryptjs . What is Bcrypt? Bcrypt is a password-hashing function designed by Niels Provos and David Mazières, based on the Blowfish cipher, and introduced at USENIX in 1999. Built-in Salt Protection: Bcrypt automatically incorporates a salt (random data) into the hashing process to protect against rainbow table attacks. Adaptive Work Factor: It is an adaptive function, meaning the iteration count (cost factor) can be increased over time to keep pace with growing computer processing power, making it highly resistant to ...