How to exclude wordpress page template(custom template) from search results?

Question

I created custom page template.

<?php
/*
 * Template Name: foo
 */
?>

This file name is "foo.php".

I tried

global $query_string;
query_posts($query_string . "&post_type=post");

But all pages will be excepted....

How to exclude only this page template from wordpress search results?

Answer 1

For anyone whom stumbles on this thread and doesn't succeed on WP newer versions: the $query args must be set instead redoing query_posts... as the follows:

// exclude any content from search results that use specific page templates
function exclude_page_templates_from_search($query) {

    global $wp_the_query;
    if ( ($wp_the_query === $query) && (is_search()) && ( ! is_admin()) ) {

            $query->set(
                'meta_query',
                array(
          array(
              'key' => '_wp_page_template',
              'value' => 'page-template-1.php',
              'compare' => '!='
              )
          )
      );
    }

}
add_filter('pre_get_posts','exclude_page_templates_from_search');

Answer 2

The query mentioned by Nicolay is very handy, but it also removes all posts from the search results, because posts do not contain the '_wp_page_template' key. To have all pages (sans the filtered template) as well as all posts you need to do the following:

// exclude any content from search results that use specific page templates
function exclude_page_templates_from_search($query) {
    global $wp_the_query;
    if ( ($wp_the_query === $query) && (is_search()) && ( ! is_admin()) ) {
        $meta_query = 
            array(
// set OR, default is AND
                'relation' => 'OR',
// remove pages with foo.php template from results
                array(
                    'key' => '_wp_page_template',
                    'value' => 'foo.php',
                    'compare' => '!='
                ),
// show all entries that do not have a key '_wp_page_template'
                array(
                    'key' => '_wp_page_template',
                    'value' => 'page-thanks.php',
                    'compare' => 'NOT EXISTS'
                )
            );
        $query->set('meta_query', $meta_query);
    }
}
add_filter('pre_get_posts','exclude_page_templates_from_search');

Extensive info on this can be found in the WordPress Codex.