Custom search: Search posts but display parent page in results

Question

I'm using Wordpress 3.5.1 with a modified twentytwelve theme. My main site structure is based on the Smooth Slider plugin (jQuery Cycle).

I have Pages that contain only a shortcode (for example, [smoothslider id='4']) to display Posts assigned to a slider. When I do a search on the site it returns result for individual posts only (and not for pages, of course). This is not what I want as there is no slider anymore. Those posts are not supposed to be displayed individually.

What I wish to do is instead of having the results with links to the single posts, have result links to the parent page. But posts have no parents so it would need to be taken from the menu_order (?) and set the results to those URLs.

---

Example

MENU:

• CAR [Page - Redirect to first child: car-1]
  • car-1 [Page - Content: shortcode with "sliderid=1"]
    
    • car-1a [Post - attached to sliderid=1 - Content: text+img]
    • car-1b [Post - attached to sliderid=1 - Content: text+img]
    • car-1c [Post - attached to sliderid=1 - Content: text+img]
  • car 2 [Page - Content: shortcode with "sliderid=2"]
    
    • car-2a [Post - attached to sliderid=2 - Content: text+img]
    • car-2b [Post - attached to sliderid=2 - Content: text+img]

---

Search results for "car":

• Results I get:
  • example.com/car-1a,
  • example.com/car-1b,
  • example.com/car-2a
  • etc.
• Results I want:
  • example.com/CAR/car-1,
  • example.com/CAR/car-2,
  • etc.

Answer 1

Ok I have figured it out; added the following to functions.php:

add_filter( 'posts_request', 'my_request_filter', 10, 2 );

function my_request_filter($sql, $query) {
    if($query->is_main_query() && is_search()) {
        $sql = "SELECT * FROM wp_posts WHERE post_content LIKE '[smoothslider%' AND post_parent !='0'";
    }
    return $sql;
}

I understand that with no access to the database or being able to run test my slider it was only guessing so I'll check your answer as accepted answer anyway. Thank you for your help.

Answer 2

I don't have your slider installed so I can't test this but something like the following is what you need:

function get_parent_page() {
  if (is_singular()) {
    global $wpdb,$post;
    if (isset($post->ID)) {
      $slide = $wpdb->get_var("SELECT DISTINCT slide_id FROM {$wpdb->prefix}smooth_slider WHERE post_id = {$post->ID} LIMIT 1");
      if (!empty($parent)) {
        $parent = $wpdb->get_var("SELECT ID FROM {$wpdb->posts} WHERE post_status = 'publish' AND post_type = 'post' AND post_content LIKE \"%[smoothslider id='".$slide."']%\"");
        if (!empty($parent)) {
           wp_safe_redirect(get_permalink($parent));
        }
      }
    }
  }
}
add_action('template_redirect','get_parent_page');

That is very query intensive, and a LIKE query is not especially efficient, but since you don't have any other way to connect the posts that is the best idea I have.

That should, if it works (again, I can't test it), redirect requests for single page results back to the parent. I recommend this approach because altering the main search query to do this will be (wildly, I think) difficult and almost certainly extremely slow. You would have to write a couple of JOINs and alter the post FIELDs and the WHERE clause. There is no way I could get that to work in any reasonable amount of time.

The other option is to alter your search.php file (or create one) so that the permalinks used point to the parent post. You could use almost the same function just pass in the post ID.

function get_parent_page_permalink($postid) {
  global $wpdb;
  if (isset($postid)) {
    $slide = $wpdb->get_var("SELECT DISTINCT slide_id FROM {$wpdb->prefix}smooth_slider WHERE post_id = {$postid} LIMIT 1");
    if (!empty($parent)) {
      $parent = $wpdb->get_var("SELECT ID FROM {$wpdb->posts} WHERE post_status = 'publish' AND post_type = 'post' AND post_content LIKE \"%[smoothslider id='".$slide."']%\"");
      if (!empty($parent)) {
         return get_permalink($parent);
      }
    }
  }
}

That is an even heavier load on the server. You will have two additional queries for each result in the search and, I believe, another query for each get_permalink.