Cart, Checkout, and Ownership

Goal

This snapshot advances Emberquay Market by teaching you to check out orders and protect seller product mutations.

Every numbered folder is a complete app. Run this stage independently, then compare it with the previous folder.

Prerequisites

Use Elixir 1.15+, Mix, Node.js 20+, and Docker for Postgres stages.

Port 4002 must be free. Copy .env.example before database stages.

• Elixir and Mix
• Node.js and npm
• Docker from part 4 onward

Concepts

Checkout creates an Order and OrderItems, clears the cart, and decrements stock. Product update/delete authorize against user ownership.

LiveView keeps interactive UI on the server; Tailwind styles the storefront; Ecto owns persistence and authorization checks.

Walkthrough

Implement checkout and seller product create/edit/delete returning 403 for non-owners.

Read the example, then open the matching snapshot. The repository includes validation, CSRF, and the surrounding structure.

Repo.transaction(fn ->
  # create order + items, decrement stock, clear cart
end)

Run and verify

Enter 09-Cart-Checkout-And-Ownership, mix deps.get, copy .env.example, migrate, seed, and start Phoenix on port 4002.

Open http://127.0.0.1:4002. From data lessons onward, Ada and Grace use password123.

docker compose up -d
git clone https://github.com/michaeldunga1/fcc-phoenix-ecommerce.git
cd fcc-phoenix-ecommerce/09-Cart-Checkout-And-Ownership
mix deps.get
npm --prefix assets install
cp .env.example .env
mix ecto.setup
mix phx.server

Troubleshooting

UI hiding is not authorization—POST as Grace against Ada's product must 403.

For database failures, confirm Docker and the ember_NN name. Never commit .env, _build, deps, or node_modules.

• Read the first exception first
• Rebuild assets after Tailwind class changes
• Never commit secrets

Try this

Complete a checkout as Ada, then attempt to delete Grace's product and confirm 403.

Test a happy path and one invalid or unauthorized request.

• Make one small change
• Test it in the browser
• Compare with the next snapshot only after it works