Stop your plugin from being used on websites hosted at wordpress.com

restrict-your-plugin-usage-on-wordpress-com.php

<?php

/**
 * Helper function to handle WordPress.com environment checks.
 *
 * @param string $plugin_slug  The plugin slug.
 * @param string $learn_more_link The link to more information.
 * @return void
 */
function wp_com_plugin_check( $plugin_slug, $learn_more_link ) {
    // Check if the site is hosted on WordPress.com.
    if ( defined( 'IS_WPCOM' ) && IS_WPCOM ) {
        // Ensure the deactivate_plugins function is available.
        if ( ! function_exists( 'deactivate_plugins' ) ) {
            require_once ABSPATH . 'wp-admin/includes/plugin.php';
        }

        // Deactivate the plugin if in the admin area.
        if ( is_admin() ) {
            deactivate_plugins( $plugin_slug );

            // Add a deactivation notice for later display.
            add_option( 'my_plugin_deactivation_notice', $learn_more_link );

            // Prevent further execution.
            return true;
        }
    }

    return false;
}

/**
 * Auto-deactivate the plugin if running in an unsupported environment.
 *
 * @return void
 */
function my_plugin_auto_deactivation() {
    if ( wp_com_plugin_check( plugin_basename( __FILE__ ), 'https://example.com/community-statement' ) ) {
        return; // Stop execution if deactivated.
    }
}
add_action( 'plugins_loaded', 'my_plugin_auto_deactivation' );

/**
 * Display an admin notice if the plugin was deactivated due to hosting restrictions.
 *
 * @return void
 */
function my_plugin_admin_notice() {
    $notice_link = get_option( 'my_plugin_deactivation_notice' );
    if ( $notice_link ) {
        ?>
        <div class="notice notice-error">
            <p>
                <?php
                echo wp_kses_post(
                    sprintf(
                        __( 'My Plugin has been deactivated because it cannot be used on WordPress.com-hosted websites. %s', 'my-plugin' ),
                        '<a href="' . esc_url( $notice_link ) . '" target="_blank" rel="noopener">' . __( 'Learn more', 'my-plugin' ) . '</a>'
                    )
                );
                ?>
            </p>
        </div>
        <?php
        delete_option( 'my_plugin_deactivation_notice' );
    }
}
add_action( 'admin_notices', 'my_plugin_admin_notice' );

/**
 * Prevent plugin activation on WordPress.com-hosted sites.
 *
 * @return void
 */
function my_plugin_activation_check() {
    if ( wp_com_plugin_check( plugin_basename( __FILE__ ), 'https://example.com/community-statement' ) ) {
        // Display an error message and stop activation.
        wp_die(
            wp_kses_post(
                sprintf(
                    '<h1>%s</h1><p>%s</p><p><a href="%s" target="_blank" rel="noopener">%s</a></p>',
                    __( 'Plugin Activation Blocked', 'my-plugin' ),
                    __( 'This plugin cannot be activated on WordPress.com-hosted websites. It is restricted due to concerns about WordPress.com policies impacting the community.', 'my-plugin' ),
                    esc_url( 'https://example.com/community-statement' ),
                    __( 'Learn more', 'my-plugin' )
                )
            ),
            esc_html__( 'Plugin Activation Blocked', 'my-plugin' ),
            array( 'back_link' => true )
        );
    }
}
register_activation_hook( __FILE__, 'my_plugin_activation_check' );

/**
 * Add a deactivation flag when the plugin is deactivated.
 *
 * @return void
 */
function my_plugin_deactivation_flag() {
    add_option( 'my_plugin_deactivation_notice', 'https://example.com/community-statement' );
}
register_deactivation_hook( __FILE__, 'my_plugin_deactivation_flag' );