bp_activity_heartbeat_last_recorded( array $response = array(), array $data = array() )

function bp_activity_heartbeat_last_recorded( $response = array(), $data = array() ) {
	if ( empty( $data['bp_activity_last_recorded'] ) ) {
		return $response;
	}

	// Use the querystring argument stored in the cookie (to preserve
	// filters), but force the offset to get only new items.
	$activity_latest_args = bp_parse_args(
		bp_ajax_querystring( 'activity' ),
		array( 'since' => date( 'Y-m-d H:i:s', $data['bp_activity_last_recorded'] ) ),
		'activity_latest_args'
	);

	if ( ! empty( $data['bp_activity_last_recorded_search_terms'] ) && empty( $activity_latest_args['search_terms'] ) ) {
		$activity_latest_args['search_terms'] = addslashes( $data['bp_activity_last_recorded_search_terms'] );
	}

	$newest_activities = array();
	$last_activity_recorded = 0;

	// Temporarily add a just-posted class for new activity items.
	add_filter( 'bp_get_activity_css_class', 'bp_activity_newest_class', 10, 1 );

	ob_start();
	if ( bp_has_activities( $activity_latest_args ) ) {
		while ( bp_activities() ) {
			bp_the_activity();

			$atime = strtotime( bp_get_activity_date_recorded() );
			if ( $last_activity_recorded < $atime ) {
				$last_activity_recorded = $atime;
			}

			bp_get_template_part( 'activity/entry' );
		}
	}

	$newest_activities['activities']    = ob_get_contents();
	$newest_activities['last_recorded'] = $last_activity_recorded;
	ob_end_clean();

	// Remove the temporary filter.
	remove_filter( 'bp_get_activity_css_class', 'bp_activity_newest_class', 10 );

	if ( ! empty( $newest_activities['last_recorded'] ) ) {
		$response['bp_activity_newest_activities'] = $newest_activities;
	}

	return $response;
}