# 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.

<div class="mockup-code bg-base-300 text-base-content shadow-xl my-8">
  <pre><code>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</code></pre>
</div>

---

## 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.

<div class="tabs tabs-box w-full mt-8 mb-12 bg-base-200/50 p-2 border border-base-300">
  <input type="radio" name="route_impl" class="tab" aria-label="Option A: Direct in main.js" checked />
  <div class="tab-content bg-base-100 border-base-300 rounded-lg p-6 mt-2">

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

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

  </div>

  <input type="radio" name="route_impl" class="tab" aria-label="Option B: Inside App.js (Persistent Layout)" />
  <div class="tab-content bg-base-100 border-base-300 rounded-lg p-6 mt-2">

```javascript
// 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))
]);
```

  </div>
</div>

---

## 4. Route Mapping Reference

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

<div class="overflow-x-auto my-8">
  <table class="table table-zebra w-full">
    <thead class="bg-base-200">
      <tr>
        <th>File Path</th>
        <th>Generated Path</th>
        <th>Description</th>
      </tr>
    </thead>
    <tbody>
      <tr>
        <td><code>index.js</code></td>
        <td class="font-mono text-primary font-bold">/</td>
        <td>The application root.</td>
      </tr>
      <tr>
        <td><code>about.js</code></td>
        <td class="font-mono text-primary font-bold">/about</td>
        <td>A static page.</td>
      </tr>
      <tr>
        <td><code>[id].js</code></td>
        <td class="font-mono text-primary font-bold">/:id</td>
        <td>Dynamic parameter (passed to the component).</td>
      </tr>
      <tr>
        <td><code>blog/index.js</code></td>
        <td class="font-mono text-primary font-bold">/blog</td>
        <td>Folder index page.</td>
      </tr>
      <tr>
        <td><code>_utils.js</code></td>
        <td class="italic opacity-50 text-error">Ignored</td>
        <td>Files starting with <code>_</code> are excluded from routing.</td>
      </tr>
    </tbody>
  </table>
</div>

---

## 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.