skill-004

ActivityPub Integrations

This skill provides guidance on integrating the ActivityPub plugin with other WordPress plugins.

Quick Reference

Integration Location

All integrations live in the integration/ directory.

File naming: class-{plugin-name}.php (following PHP conventions)

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.

Creating New Integration

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;
    }
}

Integration Patterns

Adding Post Type Support

public static function add_post_types( $post_types ) {
    $post_types[] = 'event';
    $post_types[] = 'product';
    return $post_types;
}

Custom Transformers

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

\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 );