integrations

Integration Location

All integrations live in the integration/ directory.

File naming: class-{plugin-name}.php (following [PHP conventions](../code-style/SKILL.md))

Available Integrations

• BuddyPress
• bbPress
• WooCommerce
• Jetpack
• The Events Calendar
• WP User Avatars
• And 13+ more

For complete directory structure and naming conventions, see [PHP Class Structure](../../../docs/php-class-structure.md).

Basic Integration Class

```php

namespace Activitypub\Integration;

class Plugin_Name {

public static function init() {

\add_filter( 'activitypub_transformer', array( self::class, 'custom_transformer' ), 10, 2 );

\add_filter( 'activitypub_post_types', array( self::class, 'add_post_types' ) );

}

public static function custom_transformer( $transformer, $object ) {

// Return custom transformer if needed.

return $transformer;

}

public static function add_post_types( $post_types ) {

// Add plugin's post types.

$post_types[] = 'plugin_post_type';

return $post_types;

}

}

```

Adding Post Type Support

```php

public static function add_post_types( $post_types ) {

$post_types[] = 'event';

$post_types[] = 'product';

return $post_types;

}

```

Custom Transformers

```php

public static function transformer( $transformer, $object ) {

if ( 'custom_type' === get_post_type( $object ) ) {

require_once __DIR__ . '/transformer/class-custom.php';

return new Transformer\Custom( $object );

}

return $transformer;

}

```

Modifying Activities

```php

\add_filter( 'activitypub_activity_object', function( $object, $post ) {

if ( 'product' === get_post_type( $post ) ) {

$object['type'] = 'Product';

$object['price'] = get_post_meta( $post->ID, 'price', true );

}

return $object;

}, 10, 2 );

```

Verify Integration Loading

```php

// Check if integration is active.

if ( class_exists( '\Activitypub\Integration\Plugin_Name' ) ) {

// Integration loaded.

}

```

Test Compatibility

1. Install target plugin
2. Activate ActivityPub
3. Check for conflicts
4. Verify custom post types work
5. Test federation of plugin content

Plugin Detection

```php

// Multiple detection methods.

if ( defined( 'PLUGIN_VERSION' ) ) { }

if ( function_exists( 'plugin_function' ) ) { }

if ( class_exists( 'Plugin_Class' ) ) { }

```

Hook Priority

```php

// Use appropriate priority.

add_filter( 'hook', 'callback', 20 ); // After plugin's filter.

```

Namespace Conflicts

```php

// Use fully qualified names.

$object = new \Plugin\Namespace\Class();

```

BuddyPress

• Adds BuddyPress activity support
• Custom member transformers
• Group activity federation

WooCommerce

• Product post type support
• Order activity notifications
• Customer review federation

bbPress

• Forum topic federation
• Reply activities
• User forum profiles

1. Always check if plugin is active before adding hooks
2. Use late priority for filters to override plugin defaults
3. Test with multiple plugin versions
4. Document compatibility requirements
5. Handle plugin deactivation gracefully