> For the complete documentation index, see [llms.txt](https://docs.chamilo.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.chamilo.org/3.x/developer-guide/developer-guide/plugins/plugin-architecture.md).

# Plugin Architecture

## Plugin Location

Plugins are stored in `public/plugin/`. Each plugin has its own directory:

```
public/plugin/
├── Bbb/                    # BigBlueButton integration
├── Zoom/                   # Zoom integration
├── Onlyoffice/             # OnlyOffice document editing
├── XApi/                   # xAPI/Tin Can
├── ...                     # bundled plugins ship under public/plugin/
```

## Plugin Structure

A typical plugin directory contains:

```
public/plugin/MyPlugin/
├── plugin.php              # REQUIRED — assigns $plugin_info
├── install.php             # Installation script
├── uninstall.php           # Uninstallation script
├── index.php               # Region rendering entry point (if applicable)
├── admin.php               # Admin interface (optional)
├── lang/                   # Translation files (locale codes: en_US.php, fr_FR.php, …)
├── src/
│   ├── MyPluginPlugin.php        # Main plugin class (extends Plugin)
│   ├── Entity/                   # Doctrine entities (auto-discovered)
│   ├── Repository/               # Doctrine repositories
│   └── EventSubscriber/          # Symfony event subscribers (auto-registered)
├── templates/              # Twig templates
└── resources/              # CSS/JS assets
```

## Plugin Class

Each plugin extends the `Plugin` base class (`public/main/inc/lib/plugin.class.php`) and follows the singleton pattern:

```php
class MyPluginPlugin extends Plugin
{
    protected function __construct()
    {
        $settings = ['api_key' => 'text', 'enabled' => 'boolean'];
        parent::__construct('1.0', 'Author Name', $settings);
    }

    public static function create(): static
    {
        static $instance = null;
        return $instance ??= new static();
    }
}
```

### Key Class Properties

| Property           | Type  | Effect                                  |
| ------------------ | ----- | --------------------------------------- |
| `$isCoursePlugin`  | bool  | Registers the plugin as a course tool   |
| `$isAdminPlugin`   | bool  | Adds an admin interface page            |
| `$isMailPlugin`    | bool  | Integrates with the mail system         |
| `$addCourseTool`   | bool  | Adds an icon to the course homepage     |
| `$course_settings` | array | Defines per-course configuration fields |

## Plugin Lifecycle

1. **Installation** — The admin activates the plugin, which runs `install.php`
2. **Configuration** — Settings are defined and managed through the admin panel; stored in `access_url_rel_plugin` (supports multi-tenant)
3. **Execution** — The plugin injects content into display regions or reacts to platform events
4. **Deactivation** — The plugin is disabled but its data is preserved
5. **Uninstallation** — Runs `uninstall.php` to clean up data and tables

## Display Regions

Plugins inject HTML into 18 predefined regions of the Vue frontend by overriding `renderRegion()`:

```php
public function renderRegion(string $region): string
{
    if ('footer_left' !== $region) {
        return '';
    }
    return '<p>My Plugin footer content</p>';
}
```

Available regions: `content_bottom`, `content_top`, `course_tool_plugin`, `footer_center`, `footer_left`, `footer_right`, `header_center`, `header_left`, `header_main`, `header_right`, `login_bottom`, `login_top`, `main_bottom`, `main_top`, `menu_administrator`, `menu_bottom`, `menu_top`, `pre_footer`.

## Symfony Integration

### Event Subscribers

Files ending in `EventSubscriber.php` placed inside `src/EventSubscriber/` are auto-registered via `PluginEventSubscriberPass`. They implement `EventSubscriberInterface` and react to events defined in `src/CoreBundle/Event/Events.php`.

Because the plugin class (`MyPluginPlugin`) is not a Symfony service, it cannot be autowired into the subscriber constructor. Use the `create()` singleton instead:

```php
class MyPluginEventSubscriber implements EventSubscriberInterface
{
    private MyPluginPlugin $plugin;

    public function __construct()
    {
        $this->plugin = MyPluginPlugin::create();
    }
}
```

### Doctrine Entities

Doctrine entities placed in `src/Entity/` are auto-discovered by `PluginEntityPass`. Use PHP 8 attributes for mapping. The namespace must follow `Chamilo\PluginBundle\{PluginName}`. Use unique table name prefixes (e.g., `my_plugin_*`) to avoid collisions.

### PluginHelper Service

For accessing plugin state from core Symfony services, inject `PluginHelper` rather than instantiating the plugin class directly:

```php
use Chamilo\CoreBundle\Helpers\PluginHelper;

class SomeService
{
    public function __construct(private readonly PluginHelper $pluginHelper) {}

    public function doSomething(): void
    {
        if ($this->pluginHelper->isPluginEnabled('MyPlugin')) {
            $value = $this->pluginHelper->getPluginSetting('MyPlugin', 'api_key');
        }
    }
}
```

Available methods:

| Method                                               | Purpose                                                                   |
| ---------------------------------------------------- | ------------------------------------------------------------------------- |
| `isPluginEnabled(string $name): bool`                | Check if a plugin is installed and active for the current access URL      |
| `loadLegacyPlugin(string $name): ?object`            | Instantiate and return the plugin singleton                               |
| `getPluginSetting(string $name, string $key): mixed` | Read a single plugin setting value                                        |
| `getPluginOverrides(string $name): array`            | Get `plugin.yaml` overrides (defaults + access-URL-specific) for a plugin |

## Core File References

| File                                      | Purpose                |
| ----------------------------------------- | ---------------------- |
| `public/main/inc/lib/plugin.class.php`    | Plugin base class      |
| `public/main/inc/lib/plugin.lib.php`      | Plugin manager         |
| `src/CoreBundle/Entity/Plugin.php`        | Plugin Doctrine entity |
| `src/CoreBundle/Helpers/PluginHelper.php` | PluginHelper service   |
| `src/CoreBundle/Event/Events.php`         | Event constants        |
| `public/plugin/HelloWorld/`               | Minimal example plugin |
| `public/plugin/TopLinks/`                 | Simple example plugin  |