Notes App - Server-Side Documentation

This document provides an overview of the backend implementation for the Notes App. The backend uses Node.js, Express, Sequelize, and MySQL as the database. It also integrates several features such as file uploads, user authentication, and CRUD operations for notes.

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Table of Contents

1. Technologies Used
2. Environment Setup
3. Folder Structure
4. Environment Variables
5. Database Models
6. API Routes
7. Middleware
8. Running the Server
9. Error Handling

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Technologies Used

• Node.js: Runtime environment for executing JavaScript on the server.
• Express: Web framework for building REST APIs.
• Sequelize: ORM for interacting with the MySQL database.
• MySQL: Database for storing user and note data.
• UUID: For generating unique IDs.
• dotenv: For managing environment variables.
• cors: To allow cross-origin requests.

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Environment Setup

1. Install required dependencies:

   npm install express sequelize mysql2 dotenv cors uuid

2. Install Sequelize CLI globally:

   npm install -g sequelize-cli

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Folder Structure

notapp_server/
├── config/
│   └── config.json
├── middlewares/
│   ├── AuthMiddleware.js
│   └── upload.js
├── models/
│   ├── index.js
│   ├── Notes.js
│   └── Users.js
├── routes/
│   ├── Notes.js
│   └── Users.js
├── uploads/
│   └── profileImage-[filename]
├── .gitignore
├── package-lock.json
├── package.json
├── server.js
└── .env

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Environment Variables

Ensure you have a .env file with the following variables:

PORT=3001
DB_HOST=localhost
DB_USER=root
DB_PASSWORD=password
DB_NAME=notesdb
JWT_SECRET=your_jwt_secret

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Database Models

Users Model

File: models/Users.js

module.exports = (sequelize, DataTypes) => {
  const Users = sequelize.define("Users", {
    username: { type: DataTypes.STRING, allowNull: false },
    password: { type: DataTypes.STRING, allowNull: false },
    email: { type: DataTypes.STRING, allowNull: false },
    profileImage: { type: DataTypes.STRING, allowNull: true },
  });

  Users.associate = (models) => {
    Users.hasMany(models.Notes, {
      foreignKey: "userId",
      onDelete: "CASCADE",
    });
  };

  return Users;
};

Notes Model

File: models/Notes.js

const { v4: uuidv4 } = require("uuid");
const getRandomColor = () => {
  const colors = ["#1E90FF", "#FF4500", "#32CD32", "#FFD700"];
  return colors[Math.floor(Math.random() * colors.length)];
};

module.exports = (sequelize, DataTypes) => {
  const Notes = sequelize.define("Notes", {
    id: { type: DataTypes.UUID, defaultValue: uuidv4, primaryKey: true },
    title: { type: DataTypes.STRING, allowNull: false },
    content: { type: DataTypes.STRING, allowNull: false },
    date: { type: DataTypes.DATE, defaultValue: DataTypes.NOW },
    notecolor: { type: DataTypes.STRING, defaultValue: getRandomColor },
    userId: { type: DataTypes.INTEGER, allowNull: false },
  });

  Notes.associate = (models) => {
    Notes.belongsTo(models.Users, {
      foreignKey: "userId",
      onDelete: "CASCADE",
    });
  };

  return Notes;
};

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API Routes

Users Routes

File: routes/Users.js Handles user authentication and profile management.

• POST /auth/register: Register a new user.
• POST /auth/login: Authenticate and log in a user.
• GET /auth/profile: Get the profile of the logged-in user.

Notes Routes

File: routes/Notes.js Handles CRUD operations for notes.

• POST /notes: Create a new note.
• GET /notes: Fetch all notes for a user.
• GET /notes/:id: Fetch a single note by ID.
• PUT /notes/:id: Update a note by ID.
• DELETE /notes/:id: Delete a note by ID.

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Middleware

File Uploads

• Directory: uploads/
• Files are served statically via:

  const path = require("path");
  app.use("/uploads", express.static(path.join(__dirname, "uploads")));

CORS

• Allows requests from the frontend:

  const cors = require("cors");
  app.use(cors());

JSON Parsing

• Parses incoming JSON payloads:

  app.use(express.json());

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Running the Server

1. Sync the database:

   db.sequelize.sync();

2. Start the server:

   node server.js

3. Server will be running at:

   http://localhost:3001
   

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Error Handling

Ensure proper error handling is implemented in routes and middleware. For example:

app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).json({ error: "Internal Server Error" });
});

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Future Improvements

• Implement pagination for fetching notes.
• Introduce validation for user inputs.
• Add logging for better debugging.

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code with love by

RabbitDaCoder