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

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 = filter_var( trim( $_GET['term'] ), FILTER_SANITIZE_STRING, FILTER_NULL_ON_FAILURE );
    if ( is_null( $term ) )
        return $where;

    $term = $wpdb->esc_like( $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' );