p4d-siblings.php

<?php
class P4D_Siblings extends WP_Widget
{
	/**
	 * Sets up the widgets name etc
	 */
	public function __construct()
	{
		$widget_ops = array('classname' => 'p4d_siblings', 'description' => __('Use this widget to display a list of page siblings.'));

		parent::__construct('p4d_siblings', __('P4D: Siblings', 'p4d'), $widget_ops);
	}

	/**
	 * Outputs the content of the widget
	 *
	 * @param array $args
	 * @param array $instance
	 */
	public function widget($args, $instance)
	{
		$options = wp_parse_args($instance, array(
			'title' => ''
		));

		$title = apply_filters('widget_title', $options['title'], $instance, $this->id_base);



		echo $args['before_widget'];
		?>

		<?php if(!empty($title)) : ?>
			<?php echo $args['before_title'] . $title . $args['after_title'];?>
		<?php endif; ?>
		<ul class="p4d-sibling-list">
			<?php
			global $post;
			wp_list_pages('child_of=' . $post->post_parent);
			?>
		</ul>
		<?php
		echo $args['after_widget'];
	}

	/**
	 * Outputs the options form on admin
	 *
	 * @param array $instance The widget options
	 */
	public function form($instance)
	{
		$instance = wp_parse_args($instance, array(
			'title' => ''
		));

		$title = $instance['title'];

		?>
		<p>
			<label for="<?php echo $this->get_field_id( 'title' ); ?>"><?php _e( 'Title:', 'p4d' ); ?></label>
			<input class="widefat" id="<?php echo $this->get_field_id( 'title' ); ?>" name="<?php echo $this->get_field_name( 'title' ); ?>" type="text" value="<?php echo esc_attr( $title ); ?>">
		</p>
	<?php

	}

	/**
	 * Processing widget options on save
	 *
	 * @param array $new_instance The new options
	 * @param array $old_instance The previous options
	 */
	public function update($new_instance, $old_instance)
	{
		$instance = array();

		$instance['title'] = ( ! empty( $new_instance['title'] ) ) ? strip_tags( $new_instance['title'] ) : '';

		$instance['amount'] = (int) $new_instance['amount'];

		return $instance;
	}
}