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Build a Basic Shopping Cart UI
Create a static shopping cart that calculates totals using React state.
Persist Cart to LocalStorage
Ensure users do not lose their cart when they refresh the page.
Backend Sync & Stock Validation
Build a production-grade cart that handles server validation and race conditions.
E-Commerce Shopping Cart State & Payment Integration
Shopping carts require reliable client-side state management, persistence across page refreshes, real-time total calculations, stock checks, and secure payment checkout flows. Demonstrating a clean cart architecture proves readiness for high-volume commercial web applications.
1. Cart State & Data Flow Specification
Data flow model defining item additions, quantity modifications, promo code application, and tax calculations.
2. Shopping Cart & Drawer Components
Interactive cart drawer with item quantity controls, price subtotal updates, persistent local storage, and slide-over UI.
3. Stripe Payment Gateway Checkout Handler
Stripe Checkout API integration or server-side PaymentIntent handler for processing secure transactions.
Frequently Asked Questions (E-commerce Shopping Cart)
How do you prevent client-side price manipulation in e-commerce carts?
Prices rendered in the browser UI should never be trusted during checkout. Client carts submit item IDs and quantities to the server; the backend recalculates official prices from the database before generating Stripe payment sessions.
How do you synchronize cart state across multiple open browser tabs?
Listening to window.addEventListener("storage", callback) allows tab cart states to update instantly whenever a user modifies cart items in another open tab.
Should guest carts be merged when a user logs in?
Yes, best practice is to read local guest cart items upon authentication and trigger a server mutation merging anonymous guest items into the user’s account cart.
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