Get posts by meta data OR title

Question

I have a working query that calls all my posts that have a certain meta value for one of two meta keys:

$term = $_GET['term'];
$args = array(
     'post_type' => 'some_cpt_name'
    ,'meta_query' => array(
         'relation'     => 'OR'
        ,array(
             'key'     => 'foo'
            ,'value'   => $term
            ,'compare' => 'LIKE'
         )
        ,array(
             'key'     => 'bar'
            ,'value'   => $term
            ,'compare' => 'LIKE'
         )
    ) 
);
$query = query_posts( $args );

I need to query all posts that have the $term as meta key "foo" or "bar" or as post title. Problem is how to add the post title as additional possible key?

Q: How can I also check if the $term maybe is in the post_title?

Answer 1

As with most questions involving OR clauses, the answer is the same: use a custom query or alter WP_Query using the 'posts_clauses' filter.

Answer 2

Ok, here's the final addition using the posts_clauses filter (and edit) as suggested from @scribu:

function alter_posts_where_clause( $where )
{
    global $wpdb;

    $term = trim( $_GET['term'] );
    $term = like_escape( $term );

    // Append to the WHERE clause:
    $where .= $wpdb->prepare( " OR {$wpdb->posts}.post_title LIKE '%s'", "%{$term}%" );

    return $where;
}
add_filter( 'posts_where', 'alter_posts_where_clause' );