# My Application

A Spring Boot + Vaadin project. Build your UI in pure Java — no HTML, no JavaScript.

> **New to Vaadin?** The 5-minute [Quickstart](https://vaadin.com/quickstart) walks you from here to your first running app, a live code change, and an AI-assisted edit with Copilot.

---

## Fastest start — no plugin needed

From the project folder:

```bash
./mvnw spring-boot:run        # Windows: mvnw.cmd spring-boot:run
```

No system Maven required — the wrapper is included. Then open **http://localhost:8080**.

The first start takes ~30 seconds while Maven downloads dependencies. You'll get a runnable **Task List** app: a data grid (Description / Due Date / Creation Date), a Create button, and an empty-state message. When you see that, you're running.

> **Port 8080 already in use?** Stop the other process, or set `server.port=8081` in `src/main/resources/application.properties` and open that port instead.
>
> **To stop the app:** press `Ctrl+C` in the terminal (or the red Stop button if you launched from your IDE).

## Optional upgrade — instant hotswap

Running with `spring-boot:run` works, but Java code changes need a restart. For **live reload** — edit Java, see it in the browser without restarting — install the **Vaadin plugin** and start the app through it:

- **IntelliJ IDEA:** install *Vaadin* from the JetBrains Marketplace → **Debug using Hotswap Agent** (dropdown next to Run). *Just installed it? Let IntelliJ finish indexing, or restart it, if the menu item isn't there yet.*
- **VS Code:** install the *Vaadin* extension → **Vaadin: Debug using Hotswap Agent** from the command palette.
- **Eclipse:** install the *Vaadin* plugin → right-click the project → **Run As → Vaadin Application**.

This is what makes the edit-and-see-it loop feel instant — and it's required for the AI edits in [Vaadin Copilot](https://vaadin.com/docs/latest/tools/copilot).

---

## Day 2: make your task list interactive (~10 min)

Your app lists tasks. Let's make a row do something when you click it.

**1. Add a click listener (by hand).** In `src/main/java/com/example/examplefeature/ui/TaskListView.java`, add this after the `taskGrid.addColumn(...)` block:

```java
taskGrid.addItemClickListener(event ->
    Notification.show("Due: " + Optional.ofNullable(event.getItem().getDueDate())
        .map(LocalDate::toString)
        .orElse("no due date")));
```

Add the import: `import com.vaadin.flow.component.notification.Notification;`

Save and click a task — a notification shows its due date. That's a server-side event handler, in pure Java.

**2. Let Copilot finish it.** Open Copilot (bottom-right toolbar → **Edit mode**), click the AI assistant, and try:

> When a task row is clicked, open a dialog showing its description, due date, and creation date, with a Close button.

Copilot writes the dialog into `TaskListView.java` for you. Open the file — your new code is right there.

---

## Ask your AI assistant about Vaadin (optional)

If you use Claude Code, Cursor, or another AI coding assistant, connect it to the **Vaadin MCP server** so it answers against real Vaadin docs and the exact API of your installed version — instead of guessing from outdated training data.

```bash
# One-time setup — see https://vaadin.com/docs/latest/building-apps/mcp
```

A `.mcp.json` is included (commented out by default). Uncomment it, or run the setup command above, to activate.

---

## Build for production

```bash
./mvnw package
java -jar target/*.jar
```

## Learn more

- [Vaadin Quickstart](https://vaadin.com/quickstart) — the 5-minute getting-started path
- [Components](https://vaadin.com/docs/latest/components) — 50+ UI components, all callable from Java
- [Vaadin Copilot](https://vaadin.com/docs/latest/tools/copilot) — visual + AI editing in the browser
- [Full documentation](https://vaadin.com/docs)