View difference between Paste ID: a2vPrSk2 and

 <?php
 /*
 Plugin Name: Search Post Type
 Plugin URI: http://www.duncanmorley.co.uk
 Description: A search widget that will only search a selected post type
 Author: Duncan Morley
 Version: 1.0
 Author URI: http://www.duncanmorley.co.uk
 */
 
 class SearchPostType extends WP_Widget {
 
     /** constructor */
     function SearchPostType() {
         /* Widget settings. */
 		$widget_ops = array(
 			'classname' => 'search-post-type',
 			'description' => 'A search widget that will only search a selected post type'
 		);
 
 		/* Widget control settings. */
 		$control_ops = array(
 			'width' => 350,
 			'height' => 350,
 			'id_base' => 'search-post-type'
 		);
 
 		/* Create the widget. */
 		$this->WP_Widget( 'search-post-type', 'Search Post Type', $widget_ops, $control_ops );
 
 		// my code 1
 		add_filter('pre_get_posts', array($this,'mySearchFilter'));
 
     }
 
     // begin my code 2
     function mySearchFilter($query) {
 
 	$post_type = $_GET['post_type'];
 	if (!$post_type) {
 		$post_type = 'any';
 	}
     if ($query->is_search) {
         $query->set('post_type', $post_type);
     };
     return $query;
 }
 // end mycode 2
 
 
     /** @see WP_Widget::widget */
     function widget($args, $instance) {
         extract( $args );
 
 		/* Our variables from the widget settings */
 		$title = apply_filters('widget_title', $instance['title'] );
 		$text = $instance['text'];
 		$button = $instance['button'];
 		$type = $instance['type'];
 
 		echo $before_widget;
 
 		if ( $title )
 			echo $before_title . $title . $after_title; ?>
 
 		<form method="get" id="searchform" class="clearfix" action="<?php echo esc_url( home_url( '/' ) ); ?>">
 			<input type="text" class="field" name="s" id="s" value="<?php if ( $text ) echo $text; ?>" onblur="if (this.value == ''){this.value = '<?php if ( $text ) echo $text; ?>'; }" onfocus="if (this.value == '<?php if ( $text ) echo $text; ?>') {this.value = ''; }" />
 			<input type="submit" class="submit" value="<?php if ( $button ) echo $button; ?>" />
 			<input type="hidden" name="post_type" value="<?php if ( $type ) echo $type; ?>" />
 		</form>
 
     <?php echo $after_widget;
 
 	}
 
     /** @see WP_Widget::update */
 	function update( $new_instance, $old_instance ) {
 		$instance = $old_instance;
 
 		/* Strip tags (if needed) and update the widget settings. */
 		$instance['title'] = strip_tags($new_instance['title']);
 		$instance['text'] = strip_tags($new_instance['text']);
 		$instance['button'] = strip_tags($new_instance['button']);
 		$instance['type'] = strip_tags($new_instance['type']);
 
 		return $instance;
 	}
 
     /** @see WP_Widget::form */
     function form($instance) {
         /* Set up some default widget settings. */
 		$defaults = array(
 			'title'=> __('', 'search-post-type'),
 			'text' => __('Search', 'search-post-type'),
 			'button' => __('Submit', 'search-post-type'),
 			'type' => __('', 'search-post-type')
 		);
 		$instance = wp_parse_args( (array) $instance, $defaults ); ?>
 
 		<p>
 		<label for="<?php echo $this->get_field_id('title'); ?>"><?php _e('Title:'); ?></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 $instance['title']; ?>" />
 		</p>
 		<p>
 		<label for="<?php echo $this->get_field_id('link'); ?>"><?php _e('Search Text:'); ?></label>
 		<input class="widefat" id="<?php echo $this->get_field_id('text'); ?>" name="<?php echo $this->get_field_name('text'); ?>" type="text" value="<?php echo $instance['text']; ?>" />
 		</p>
 		<p>
 		<label for="<?php echo $this->get_field_id('button'); ?>"><?php _e('Submit Text:'); ?></label>
 		<input class="widefat" id="<?php echo $this->get_field_id('button'); ?>" name="<?php echo $this->get_field_name('button'); ?>" type="text" value="<?php echo $instance['button']; ?>" />
 		</p>
 		<p>
 		<label for="<?php echo $this->get_field_id('type'); ?>"><?php _e('Post Type:'); ?></label>
 		<select id="<?php echo $this->get_field_id('type'); ?>" name="<?php echo $this->get_field_name('type'); ?>" class="widefat" style="width:100%;">
 			<option <?php if ( 'any' == $instance['type'] ) echo 'selected="selected"'; ?> value="any">any</option>
 			<?php
 			$args=array(
 				'public' => true
 			);
 			$post_types=get_post_types($args,'names');
 			foreach ($post_types as $post_type ) {
 				$selected = $post_type == $instance['type'] ? 'selected="selected"' : "";
 			  echo '<option '.$selected.' value='.$post_type.'>'.$post_type.'</option>';
 			} ?>
 		</select>
 		</p>
 
         <?php
 
     }
 
 } // class SearchPostType
 
 // mycode 3
 add_action( 'widgets_init', create_function( '', 'register_widget("SearchPostType");' ) );
 
 
 ?>