Custom Post Widget

<?php
/**
 * Makes a custom Widget for displaying information posts
 *
 * Learn more: http://codex.wordpress.org/Widgets_API#Developing_Widgets
 *
 * @package WordPress
 * @subpackage Twenty_Eleven
 * @since Twenty Eleven 1.0
 */
class Information_Widget extends WP_Widget {

    function Information_Widget() {
        $widget_ops = array( 'classname' => 'information_widget', 'description' => __( 'Use this widget to display Information Posts', 'twentyeleven' ) );
        $this->WP_Widget( 'information_widget', __( 'Information Posts', 'twentyeleven' ), $widget_ops );
        $this->alt_option_name = 'information_widget';

        add_action( 'save_post', array(&$this, 'flush_widget_cache' ) );
        add_action( 'deleted_post', array(&$this, 'flush_widget_cache' ) );
        add_action( 'switch_theme', array(&$this, 'flush_widget_cache' ) );
    }

    function widget( $args, $instance ) {
        $cache = wp_cache_get( 'information_widget', 'widget' );

        if ( !is_array( $cache ) )
            $cache = array();

        if ( ! isset( $args['widget_id'] ) )
            $args['widget_id'] = null;

        if ( isset( $cache[$args['widget_id']] ) ) {
            echo $cache[$args['widget_id']];
            return;
        }

        ob_start();
        extract( $args, EXTR_SKIP );

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

        if ( ! isset( $instance['postid'] ) )
            $postid = 0;

        if ( ! $postid = absint( $instance['postid'] ) )
            $postid = 0;

        $thumbnail = ( isset( $instance['thumbnail'] ) ) ? $instance['thumbnail'] : false;
        $excerpt = ( isset( $instance['excerpt'] ) ) ? $instance['excerpt'] : false;
        // Set the global arguments
        global $widget_args;
        $widget_args=array();
        $widget_args['postid'] = $postid;
        $widget_args['thumbnail'] = $thumbnail;
        $widget_args['excerpt'] = $excerpt;
        $widget_args['uid'] = '-' .$args['widget_id'];

        // Display the infomation post
        echo $before_widget;
        echo $before_title;
        echo $title; // Can set this with a widget option, or omit altogether
        echo $after_title;
        get_template_part('information','html');
        echo $after_widget;

        // Reset the post globals as this query will have stomped on it
        wp_reset_postdata();

        $cache[$args['widget_id']] = ob_get_flush();

        wp_cache_set( 'information_widget', $cache, 'widget' );
    }

    /**
     * Deals with the settings when they are saved by the admin. Here is
     * where any validation should be dealt with.
     **/
    function update( $new_instance, $old_instance ) {
        $instance = $old_instance;
        $instance['title'] = strip_tags( $new_instance['title'] );
        $instance['postid'] = (int) $new_instance['postid'];
        $instance['thumbnail'] = $new_instance['thumbnail'];
        $instance['excerpt'] = $new_instance['excerpt'];
        $this->flush_widget_cache();
        $alloptions = wp_cache_get( 'alloptions', 'options' );
        if ( isset( $alloptions['information_widget'] ) )
            delete_option( 'information_widget' );
        return $instance;
    }

    function flush_widget_cache() {
        wp_cache_delete( 'information_widget', 'widget' );
    }

    /**
     * Displays the form for this widget on the Widgets page of the WP Admin area.
     **/
    function form( $instance ) {
        $title = isset( $instance['title']) ? esc_attr( $instance['title'] ) : '';
        $postid = isset( $instance['postid'] ) ? absint( $instance['postid'] ) : 0;
        $thumbnail = ( isset( $instance['thumbnail'] ) ) ? $instance['thumbnail'] : false;
        $excerpt = isset( $instance['excerpt'] ) ? strip_tags( $instance['excerpt'] )  : false;
        $postlist = dr_info_get_posts();
    ?>
        <p><label for="<?php echo esc_attr( $this->get_field_id( 'title' ) ); ?>"><?php _e( 'Information Title', 'twentyeleven' ); ?></label>
        <br/>
        <input class="widefat" id="<?php echo esc_attr( $this->get_field_id( 'title' ) ); ?>" name="<?php echo esc_attr( $this->get_field_name( 'title' ) ); ?>" type="text" value="<?php echo esc_attr( $title ); ?>" /></p>

        <p><label for="<?php echo $this->get_field_id('postid'); ?>"><?php _e("Information Post Title"); ?></label>
        <br/>
        <select id="<?php echo $this->get_field_id('postid'); ?>" name="<?php echo $this->get_field_name('postid'); ?>">
    <?php
        foreach ($postlist as $output) :
            $selected = ( $output['value'] == esc_attr($postid) ) ? ' selected = "selected" ' : '';
            $option = '<option '.$selected .'value="' . $output['value'];
            $option = $option .'">';
            $option = $option .$output['label'];
            $option = $option .'</option>';
            echo $option;
        endforeach;
    ?>
        </select></p>

        <p><label for="<?php echo $this->get_field_id('thumbnail'); ?>"><?php _e("Hide Post Featured Image"); ?></label>
        <br/>
        <?php $checked = ( $thumbnail ) ? ' checked=\"checked\" ' : ''; ?>
        <input type="checkbox" id="<?php echo $this->get_field_id('thumbnail'); ?>" name="<?php echo $this->get_field_name('thumbnail'); ?>" value="true" <?php echo $checked; ?> />
        </p>

        <p><label for="<?php echo $this->get_field_id('excerpt'); ?>"><?php _e("Display Post Excerpt Only"); ?></label>
        <br/>
        <?php $checked = ( $excerpt ) ? ' checked=\"checked\" ' : ''; ?>
        <input type="checkbox" id="<?php echo $this->get_field_id('excerpt'); ?>" name="<?php echo $this->get_field_name('excerpt'); ?>" value="true" <?php echo $checked; ?> />
        </p>

        <?php
    }
}
?>