Posts CRUD and Ownership

Goal

This snapshot advances Baltic Post by teaching you to create, edit, and delete posts with owner authorization.

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

Prerequisites

Use JDK 17+, Gradle, and Docker for Postgres stages.

Port 8090 must be free. Copy .env.example before starting database stages.

• JDK 17+ and Gradle
• A code editor and terminal
• Docker from part 4 onward

Concepts

Authorization compares session user with post.authorId.

Keep handlers thin: routes accept input, Exposed tables enforce rules, and FreeMarker escapes output by default.

Walkthrough

Return 403 when another account mutates.

Read the example, then open the matching snapshot. The repository includes the surrounding setup and error handling.

if (session?.userId != post.authorId) call.respond(HttpStatusCode.Forbidden)

Run and verify

Enter 09-Posts-CRUD-And-Ownership, run Gradle, copy .env.example, and start Ktor on port 8090.

Open http://127.0.0.1:8090. Watch the terminal for validation and database errors.

docker compose up -d
git clone https://github.com/michaeldunga1/fcc-ktor-blog.git
cd fcc-ktor-blog/09-Posts-CRUD-And-Ownership
cp .env.example .env
./gradlew run

Troubleshooting

UI hiding is not authorization.

For database failures, confirm Docker and the baltic_NN name when applicable. Never commit .env or local.properties secrets.

• Read the first error first
• Restart after environment changes
• Never commit secrets

Try this

Log in as Ada and confirm Grace's post returns 403 on delete.

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