Smarter BuddyPress sitewide notices widget that doesn't display the widget when there are no notices to show

Smart_Sitewide_Notices_Widget.class.php

<?php
/**
 * Smarter version of the buddypress sitewide notices widget
 *
 * Fetches the notices in an output buffer and does not display widget when
 * there is no content to display.
 * 
 * Sadly this widget is necessary because buddypress only finds out if there
 * are notices to be displayed while displaying them.
 *
 * This code would extend BP_Messages_Sitewide_Notices_Widget, but it's constructor
 * is hardwired to register itself so I had to copy all it's methods too :(
 *
 * I'm using the buddypress textdomain as that probably makes more sense than
 * registering my own.
 * 
 * @see BP_Messages_Sitewide_Notices_Widget
 * @see bp_message_get_notices()
 */
class Smart_Sitewide_Notices_Widget extends WP_Widget {
	/**
	 * Register widget
	 */
	function __construct() {
		parent::__construct(
			'smart_sitewide_notices_widget',
			__( 'Smart BuddyPress Sitewide Notices', 'buddypress' ),
			array(
				'classname'   => 'widget_smart_sitewide_notices_widget buddypress widget',
				'description' => __( 'Display Sitewide Notices posted by the site administrator', 'buddypress' ),
			)
		);
	}

	/**
	 * Render the widget.
	 *
	 * @see WP_Widget::widget() for a description of parameters.
	 *
	 * @param array $args See {@WP_Widget::widget()}.
	 * @param array $args See {@WP_Widget::widget()}.
	 */
	public function widget( $args, $instance ) {
		if ( ! is_user_logged_in() ) {
			return;
		}

		// Don't display the widget if there are no notices to show
		$notices = BP_Messages_Notice::get_active();
		if ( empty( $notices ) ) {
			return;
		}

		extract( $args );

		$title = ! empty( $instance['title'] ) ? $instance['title'] : '';
		$title = apply_filters( 'widget_title', $title, $instance );

		// fetch notices in an output buffer and don't display them if there's nothing there
		ob_start();
		bp_message_get_notices();
		$notices = ob_get_clean();
		if (!strlen($notices)) {
			return;
		}

		printf('%s%s%s%s<div class="bp-site-wide-message">%s</div>%s',
			$before_widget,
			$before_title,
			$title,
			$after_title,
			$notices,
			$after_widget
		);
	}

	/**
	 * Process the saved settings for the widget.
	 *
	 * @see WP_Widget::update() for a description of parameters and
	 *      return values.
	 *
	 * @param array $new_instance See {@WP_Widget::update()}.
	 * @param array $old_instance See {@WP_Widget::update()}.
	 * @return array $instance See {@WP_Widget::update()}.
	 */
	public function update( $new_instance, $old_instance ) {
		$instance = $old_instance;
		$instance['title'] = strip_tags( $new_instance['title'] );
		return $instance;
	}

	/**
	 * Render the settings form for Appearance > Widgets.
	 *
	 * @see WP_Widget::form() for a description of parameters.
	 *
	 * @param array $instance See {@WP_Widget::form()}.
	 */
	public function form( $instance ) {
		$instance = wp_parse_args( (array) $instance, array(
			'title' => '',
		) );

		$title = strip_tags( $instance['title'] );

		printf('<p>
			<label for="%s">%s</label>
			<input class="widefat" id="%s" name="%s" type="text" value="%s" />
		</p>
		',
		$this->get_field_id( 'title' ),
		__( 'Title:', 'buddypress' ),
		$this->get_field_id( 'title' ),
		$this->get_field_name( 'title' ),
		esc_attr( $title )
		);
	}
}