# Vite Plugin: File-based Routing

The `sigproRouter` plugin for Vite automates route generation by scanning your `pages` directory. It creates a **virtual module** that you can import directly into your code, eliminating the need to maintain a manual routes array.

## 1. Project Structure

To use the plugin, organize your files within the `src/pages` directory. The folder hierarchy directly determines your application's URL structure. SigPro uses brackets `[param]` for dynamic segments.

```text
my-sigpro-app/
├── src/
│   ├── pages/
│   │   ├── index.js          →  #/
│   │   ├── about.js          →  #/about
│   │   ├── users/
│   │   │   └── [id].js       →  #/users/:id
│   │   └── blog/
│   │       ├── index.js      →  #/blog
│   │       └── [slug].js     →  #/blog/:slug
│   ├── App.js                (Main Layout)
│   └── main.js               (Entry Point)
├── vite.config.js
└── package.json
```

---

## 2. Setup & Configuration

Add the plugin to your `vite.config.js`. It works out of the box with zero configuration.

```javascript
// vite.config.js
import { defineConfig } from 'vite';
import { sigproRouter } from 'sigpro/vite';

export default defineConfig({
  plugins: [sigproRouter()]
});
```

---

## 3. Implementation

Thanks to **SigPro's synchronous initialization**, you no longer need to wrap your mounting logic in `.then()` blocks.

### Option A: Direct in `main.js`
Ideal for single-page applications where the router controls the entire viewport.

```javascript
// src/main.js
import { $ } from 'sigpro';
import { routes } from 'virtual:sigpro-routes';

// The Core already has $.router ready
$.mount($.router(routes), '#app');
```

### Option B: Inside `App.js` (Persistent Layout)
Recommended for professional apps with a fixed Sidebar or Navbar that should not re-render when changing pages.

```javascript
// src/main.js
import { $ } from 'sigpro';
import App from './App.js';

$.mount(App, '#app');

// src/App.js
import { routes } from 'virtual:sigpro-routes';

export default () => div({ class: 'layout' }, [
  header([
    h1("SigPro App"),
    nav([
      button({ onclick: () => $.router.go('/') }, "Home"),
      button({ onclick: () => $.router.go('/blog') }, "Blog")
    ])
  ]),
  // Only the content inside <main> will be swapped reactively
  main($.router(routes))
]);
```

---

## 4. Route Mapping Reference

The plugin follows a simple convention to transform your file system into a routing map.

| File Path | Generated Path | Description |
| :--- | :--- | :--- |
| `index.js` | `/` | The application root. |
| `about.js` | `/about` | A static page. |
| `[id].js` | `/:id` | Dynamic parameter (passed to the component). |
| `blog/index.js` | `/blog` | Folder index page. |
| `_utils.js` | *Ignored* | Files starting with `_` are excluded from routing. |

---

## 5. How it Works (Vite Virtual Module)

The plugin generates a virtual module named `virtual:sigpro-routes`. This module exports an array of objects compatible with `$.router()`:

```javascript
// Internal representation generated by the plugin
export const routes = [
  { path: '/', component: () => import('/src/pages/index.js') },
  { path: '/users/:id', component: () => import('/src/pages/users/[id].js') },
  // ...
];
```

Because it uses dynamic `import()`, Vite automatically performs **Code Splitting**, meaning each page is its own small JS file that only loads when the user navigates to it.

