How to interfere to default search to make it search in custom fields?

Question

I'm trying to interfere default WP search (?s=) to make it search through posts custom fields.

Firstly I'm trying to debug my search with this piece of code in functions.php:

function add_search_in_custom_fields( $query ) {
    $query->set(
        'post_type', 'my_post_type',
        'meta_query', array(
            array(
                'key'     => 'my_key_title',
                'value'   => 'my_value_title',
                'compare' => 'LIKE'
            )
        )
    );
    return $query;
}
add_action( 'pre_get_posts', 'add_search_in_custom_fields' );

What's strange - that I'm getting all posts (with my_post_type) - doesn't matter if there is value or not in posts custom field.

Seems like $query doesn't look at meta_query parameters at all.

Any ideas?

Answer 1

You are getting all post because you didn't pass meta query correctly. Try this below code

function add_search_in_custom_fields( $query ) {

  // check the query type.
  if ( $query->is_search ) {

    $meta_array = array(
      array(
        'key' => 'my_key_title',
        'value' => $query->query_vars['s'] ,
        'compare' => 'LIKE',
      ),
    );

    // set meta query.
    $query->set('meta_query', $meta_array);
  };
}
add_filter( 'pre_get_posts', 'add_search_in_custom_fields');

Hope this help !