Wordpress - Display only pages with specific template in search results - php

Question

I want to display in my WP search results ONLY pages with specific template beceuse I trying to build product catalog without any plugins. Pure WP code. Some pages are my products, and they have product.php template file. This is my search.php:
<?php
if ( have_posts() ) :
while ( have_posts() ) :
the_post();
get_template_part( 'template-parts/post/content', 'excerpt' );
endwhile;
the_posts_pagination();
else :
?>
<p><?php _e( 'No results.' ); ?></p>
<?php
get_search_form();
endif;
?>
And the question is, how to display only my product pages without any other pages?

Answer 1

Try this out!
This function will interrupt the search query and add some condition fo the query to returns specific pages.
//Filter the search for only posts and parts
function SearchFilter($query)
{
// Now filter the posts
if ($query->is_main_query() & $query->is_search && $search_template) {
$query->set('post_type', 'page');
$query->set('meta_key' => '_wp_page_template',);
$query->set('meta_value' => 'product.php');
}
// Returning the query after it has been modified
return $query;
}
add_action('pre_get_posts', 'SearchFilter');
Explaining the code:
The "post_type" will limit this filter for page post type only.
The condition Will limit this filter to only work on the search queries and not every time the posts query is called.
$query->is_search && $search_template
These parameters will filter the returned posts by the meta_key "_wp_page_template" which contains the page template, so we only return the pages with the page template "product.php".
$query->set('meta_key' => '_wp_page_template',);
$query->set('meta_value' => 'product.php');