<?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");' ) );


?>