pre_get_posts and search query for admin

Question

I'm going round in circles with trying to include several custom fields in my search results. The custom fields are managed via ACF.

At first I want this for the admin. /wp-admin/edit.php?post_type=location.

I can't see why this wont work. I have tried variations of it and different orders. I've also gone through the posts_search filter route with arrays but just can't get this to work.

Any help appreciated.

add_filter('pre_get_posts', __NAMESPACE__ . '\\search_custom_fields');

function search_custom_fields($query)
{
if ($query->is_search && $query->is_main_query()) {
    // this works.
    echo "search_custom_fields:   " . $query->is_main_query() . " " . $query->is_search;
    echo "Setting meta_query in search_custom_fields. ";

    $search_word = get_query_var('s');

    $meta_query = array(
        'relation' => 'OR',
        array(
            'key'     => 'loc_refid',
            'value'   => get_search_query(),
            'compare' => 'LIKE',
        ), array(
            'key'     => 'location_postcode_preview',
            'value'   => get_search_query(),
            'compare' => 'LIKE',
        ),
    );

    // if i uncomment this no results appear?!
    // $query->set('meta_query', $meta_query);

    // these work have an affect on the results
    $query->set('orderby', 'date');  
    $query->set('order', 'ASC');

}

return $query;

}

print_r($query) gives me -

 [query_vars]=>
        [meta_query] => Array
                (
                    [key] => loc_refid
                    [value] => MN0068
                    [compare] => LIKE
                )

 [meta_query] =>  
 [date_query] => 
 [post_count] => 0
 ...

thanks in advance.

Answer 1

So turns out you can't actually add ACF / custom fields to the search query in this way. It seems to force and AND into the query.

I've used a mixture of sources to create the below which now works really well.

/* ADD META FIELD TO SEARCH QUERY */
// fields for Ajax search, admin and normal search
if (!isset($GLOBALS['current_screen']) && !is_customize_preview()):
    // DAMN AJAX! is_admin() is always true when using it ;-/
    add_meta_field_to_search_query('loc_refid');
        add_meta_field_to_search_query('location_postcode_preview');
    add_meta_field_to_search_query('location_region');
    add_meta_field_to_search_query('location_areas');

elseif (is_admin()):
    add_meta_field_to_search_query('loc_refid');
    add_meta_field_to_search_query('location_postcode');
    add_meta_field_to_search_query('location_postcode_preview');
    add_meta_field_to_search_query('location_region');
    add_meta_field_to_search_query('location_areas');
    add_meta_field_to_search_query('location_map_position' );
    add_meta_field_to_search_query('user_organisation');
    add_meta_field_to_search_query('user_position');
    add_meta_field_to_search_query('client_location');
    add_meta_field_to_search_query('user_email');
else:
    add_meta_field_to_search_query('loc_refid');           
    add_meta_field_to_search_query('location_postcode_preview');
    add_meta_field_to_search_query('location_region');
    add_meta_field_to_search_query('location_areas');

endif;

function add_meta_field_to_search_query($field, $condition = "LIKE")
{
    // echo "add_meta_field_to_search_query; field:$field";

    if (isset($GLOBALS['added_meta_field_to_search_query'])) {
        $GLOBALS['added_meta_field_to_search_query'][] = '\'' . $field . '\'';
        return;
    }

    $GLOBALS['added_meta_field_to_search_query']   = array();
    $GLOBALS['added_meta_field_to_search_query'][] = '\'' . $field . '\'';

    add_filter('posts_join', function ($join) {
        // echo "$s 'posts_join' <br />";
        global $wpdb;
        if (is_search()) {
            $join .= " LEFT JOIN $wpdb->postmeta ON $wpdb->posts.ID = $wpdb->postmeta.post_id ";
        }
        return $join;
    });

    add_filter('posts_groupby', function ($groupby) {
        // echo "$s 'posts_groupby' <br />";
        global $wpdb;
        if (is_search()) {
            $groupby = "$wpdb->posts.ID";
        }
        return $groupby;
    });

    add_filter('posts_search', function ($search_sql) {
        global $wpdb;

        $search_terms = get_query_var('search_terms');

        if (!empty($search_terms)) {
            // echo "posts_search<br />";
            // print_r($search_terms);
            foreach ($search_terms as $search_term) {
                // echo "search_term: $search_term<br />";
                $old_or     = "OR ({$wpdb->posts}.post_content LIKE '{$wpdb->placeholder_escape()}{$search_term}{$wpdb->placeholder_escape()}')";
                $new_or     = $old_or . " OR ({$wpdb->postmeta}.meta_value LIKE '{$wpdb->placeholder_escape()}{$search_term}{$wpdb->placeholder_escape()}' AND {$wpdb->postmeta}.meta_key IN (" . implode(', ', $GLOBALS['added_meta_field_to_search_query']) . "))";
                $search_sql = str_replace($old_or, $new_or, $search_sql);
            }
        }

        $search_sql = str_replace(" ORDER BY ", " GROUP BY $wpdb->posts.ID ORDER BY ", $search_sql);

        return $search_sql;
    });

    // ajax seach only, basically same as above but checking for $GLOBALS['fd_search_term'] which holds the search string
    add_filter('posts_where', function ($search_sql) {
        global $wpdb;

        // print_r($wpdb);
        $search_terms = explode(' ', $GLOBALS['fd_search_term']);

        // if (!empty($search_terms) && !isset($GLOBALS['current_screen']) && !is_customize_preview() && !is_search()) {

        if ($GLOBALS['fd_search_term']) {
            // echo "AJAX posts_search<br />";
            // print_r($search_terms);
            foreach ($search_terms as $search_term) {
                // echo "search_term: $search_term<br />";
                $old_or     = "OR ({$wpdb->posts}.post_content LIKE '{$wpdb->placeholder_escape()}{$search_term}{$wpdb->placeholder_escape()}')";
                $new_or     = $old_or . " OR ({$wpdb->postmeta}.meta_value LIKE '{$wpdb->placeholder_escape()}{$search_term}{$wpdb->placeholder_escape()}' AND {$wpdb->postmeta}.meta_key IN (" . implode(', ', $GLOBALS['added_meta_field_to_search_query']) . "))";
                $search_sql = str_replace($old_or, $new_or, $search_sql);
            }
        }

        $search_sql = str_replace(" ORDER BY ", " GROUP BY $wpdb->posts.ID ORDER BY ", $search_sql);

        return $search_sql;
    });

}

Answer 2

Have you tried it with add_action instead of add_filter ?

add_action('pre_get_posts', 'search_custom_fields');

Is public set to true for your post_type?

And for use on in admin, try:

if ( is_admin() && $query->is_main_query() ) {
    if ( $query->is_search ) {
       //etc.