Code snippet for sending local notification

post-published-notification.php

<?php
/**
* @copyright https://gist.github.com/modemlooper/9693b591d8c36288496d
*/

/**
 * Component
 *
 * @param array $component_names Component names.
 *
 * @return array
 */
function buddydev_notification_register_component( $component_names = array() ) {

	if ( ! is_array( $component_names ) ) {
		$component_names = array();
	}

	array_push( $component_names, 'wp_post' );

	return $component_names;
}
add_filter( 'bp_notifications_get_registered_components', 'buddydev_notification_register_component' );


// this gets the saved item id, compiles some data and then displays the notification
function buddydev_format_post_published_notification( $action, $item_id, $secondary_item_id, $total_items, $format, $component_action, $component_name ) {

	if ( 'wp_post_published' != $component_action || 'wp_post' != $component_name ) {
		return $action;
	}

	$post = get_post( $item_id );

	$post_link = get_permalink( $post );
	$text      = bp_core_get_user_displayname( $post->post_author ) . __( ' has published a new post.' );

	if ( 'string' === $format ) {
		$return = sprintf( '<a href="' . esc_url( $post_link ) . '">' . esc_html( $text ) . '</a>', $text, $post_link );
	} else {
		$return = array(
			'text' => $text,
			'link' => $post_link,
		);
	}

	return $return;
}
add_filter( 'bp_notifications_get_notifications_for_user', 'buddydev_format_post_published_notification', 10, 7 );

/**
 * Add custom notifiction on post publish
 *
 * @param string  $new_status New post status.
 * @param string  $old_status Old post status.
 * @param WP_Post $post       Post object.
 */
function buddydev_notify_friends_on_post_published( $new_status, $old_status, $post ) {
  
  if ( ! function_exists( 'bp_is_active' ) || ! bp_is_active( 'notifications' ) ) {
		return;
	}

	if ( 'publish' !== $new_status || 'publish' === $old_status ) {
		return;
	}

	$friend_ids = friends_get_friend_user_ids( $post->post_author );

	if ( ! $friend_ids ) {
		return;
	}

	foreach ( $friend_ids as $friend_id ) {
		bp_notifications_add_notification(
			array(
				'user_id'           => $friend_id,
				'item_id'           => $post->ID,
				'secondary_item_id' => $post->post_author,
				'component_name'    => 'wp_post',
				'component_action'  => 'wp_post_published',
				'date_notified'     => bp_core_current_time(),
				'is_new'            => 1,
			)
		);
	}
}
add_action( 'transition_post_status', 'buddydev_notify_friends_on_post_published', 99, 3 );