Search results to be only posts & children of page ID

Question

I'm trying to have my search results show only results that are a child of the 'news' category or a child of the 'work' page (ID = 16).

This is what I have so far:

    function SearchFilter($query) {
        if ($query->is_search) {
            $query->set('category_name', 'news');
            $query->set('post_parent', '16');            

        }
        return $query;
    }

    add_filter('pre_get_posts','SearchFilter'); 

The problem is it only searches for posts that belong to 'news' AND have a parent page ID of '16', which is obviously no posts.

So how do better refine search? I'd prefer not to use a plugin, that's why i am here.

Thanks, Drew

Answer 1

The only way I could figure it out was to build a list of ID's to exclude like this:

/*
* Hide some pages from search results
*/
function SearchFilter($query) {
    if ($query->is_search) {

        $exclude = '18,20,12,22,132,76,81,78,84,91';
        // Get all children of #18
        $pages = get_pages('post_parent=18');
            foreach($pages as $child) {            
            $exclude .=  "," . $child->ID;
        }

        $query->set('post__not_in', explode(",", $exclude));                        
    }
    return $query;
}

add_filter('pre_get_posts','SearchFilter'); 

You could use any of the WP_Query parameters to do similar things (like a build a list of ID's to include).