Social Media Post Management

A small recommendation demo that uses a Node/Express backend with MongoDB and a React frontend. The backend serves simple user and post endpoints and implements a lightweight recommendation endpoint that prioritizes posts matching user interests and then popular posts.

Repo layout

• backend/ - Express server connecting to MongoDB. Key files:

  • server.js - main server and API routes
  • package.json - backend dependencies

• frontend/ - Create React App frontend. Key files:

  • package.json - frontend scripts and deps
  • build/ - production build output (already present)
  • src/ - React source (pages: home.js, feed.js, login.js)

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Requirements

• Node.js (16+ recommended)
• npm or yarn
• MongoDB running locally (default URI used: mongodb://localhost:27017)

Backend

The backend is a minimal Express app. It expects a running MongoDB instance on mongodb://localhost:27017 and uses a database named recommend with two collections: users and posts.

Main endpoints (defined in backend/server.js):

• POST /login

  • Body: { username, password }
  • Response: { status: "success", userId } or { status: "failed" }

• POST /addPost

  • Body: { userId, content, tags }
  • Adds a post for the user. Returns { status: "success", postId }

• POST /deletePost

  • Body: { userId, postId }
  • Deletes a post if it belongs to the user.

• GET /feed

  • Returns all posts

• POST /like

  • Body: { userId, postId }
  • Toggles like/unlike. If liked, post.tags (if any) are added to the user's interests array.

• POST /recommend

  • Body: { userId }
  • Returns posts prioritized by user's interests (matching tags) sorted by like count, followed by other popular posts.

The server listens on port 5000 by default.

Start the backend:

cd backend
npm install
node server.js

(You can also use a process manager like nodemon during development.)

Frontend

The frontend is a Create React App project. Scripts are standard:

• npm start - start dev server
• npm run build - produce production build into frontend/build

Start the frontend (development):

cd frontend
npm install
npm start

Data notes

• The backend uses a users collection. Users should have _id, username, password, and optionally interests (array of tags).
• The posts collection stores posts with fields: userId, user (username), content, tags (array), likes (array of userIds).

Known limitations

• No authentication/session management — the demo uses plain username/password checks and returns the user _id to represent an authenticated user.
• Passwords are stored in plaintext in this example (unsafe for production). Use hashing, HTTPS, and proper auth for real apps.
• No rate limiting, input validation, or robust error handling — suitable for demo and learning only.

Next steps / improvements

• Add proper auth (JWT or sessions), password hashing
• Add input validation and error handling
• Add unit/integration tests
• Add environment-based configuration (use .env for MongoDB URI, ports)
• Add CORS restrictions and production-ready security hardening

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