A widget to display a Featured Custom Post Type in WordPress

featured_custom_post_type_widget.php

<?php
/*
Plugin Name: Featured Custom Post Type Widget
Plugin URI: http://www.sennza.com.au
Description: Lists out all the custom post type posts in a dropdown so the user can selected a CPT to feature.
Version: 1.0
Author: Bronson Quick
Author URI: http://www.sennza.com.au
License: GPL2

Use this with your custom post type and alter the 2 references to: 'post_type' => 'case_study' to your own CPT
The other 'gotcha' for this widget is that your Custom Post Type needs to have 'hierarchical' => 'true' in your
register_post_type function

*/
class Sennza_Featured_Case_Study extends WP_Widget {

	/**
	 * Register widget with WordPress.
	 */
	public function __construct() {
		parent::__construct(
	 		'featured_case_study', // Base ID
			'Featured Case Study', // Name

			array( 'description' => __( 'A widget to display a featured case study', 'text_domain' ), ) // Args
		);
	}

	/**
	 * Front-end display of widget.
	 *
	 * @see WP_Widget::widget()
	 *
	 * @param array $args     Widget arguments.
	 * @param array $instance Saved values from database.
	 */
	public function widget( $args, $instance ) {
		extract( $args );
		$featured_post = apply_filters( 'featured_post', $instance['featured_post'] );
        $args = array(
            'p' => $featured_post,
            'post_type' => 'case_study');
        $featured_case_study = new WP_Query( $args);
		echo $before_widget;
        if ($featured_case_study->have_posts()) : while ($featured_case_study->have_posts()) : $featured_case_study->the_post();?>
        <h3><?php the_title();?></h3>
        <?php the_excerpt(); ?>
        <?php endwhile; endif; ?>
    <?php
		echo $after_widget;
	}

	/**
	 * Sanitize widget form values as they are saved.
	 *
	 * @see WP_Widget::update()
	 *
	 * @param array $new_instance Values just sent to be saved.
	 * @param array $old_instance Previously saved values from database.
	 *
	 * @return array Updated safe values to be saved.
	 */
	public function update( $new_instance, $old_instance ) {
		$instance = $old_instance;
		$instance['featured_post'] = strip_tags( $new_instance['featured_post'] );

		return $instance;
	}

	/**
	 * Back-end widget form.
	 *
	 * @see WP_Widget::form()
	 *
	 * @param array $instance Previously saved values from database.
	 */
	public function form( $instance ) {
        $featured_post = $instance['featured_post'];
        $case_study_args = array(
          'post_type' => 'case_study',
          'posts_per_page' => '-1'
        );
        $case_studies = new WP_Query( $case_study_args );
		?>
		<p>
        <fieldset>
        <label for="<?php echo $this->get_field_id( 'featured_post' ); ?>">Select a  case study:</label>
        <select id="<?php echo $this->get_field_id( 'featured_post' ); ?>" name="<?php echo $this->get_field_name('featured_post');?> ">
            <?php if ($case_studies->have_posts()) : while ($case_studies->have_posts()) : $case_studies->the_post();?>
            <option value="<?php the_ID(); ?>" <?php selected( $featured_post, get_the_ID()); ?>><?php the_title();?></option>
            <?php endwhile; endif; ?>
        </select>
        </fieldset>
		</p>
		<?php
	}
}
add_action( 'widgets_init', create_function( '', 'register_widget( "Sennza_Featured_Case_Study" );' ) );
?>