Modify post type when using XML-RPC

gistfile1.php

function redirect_xmlrpc_to_custom_post_type ($data, $postarr) {
    // This function detects a XML-RPC request and modifies it before posting

    $p2_custom_post_type = 'FanPost'; // Define your Custom post type

    if (defined('XMLRPC_REQUEST') || defined('APP_REQUEST')) {
        $data['post_type'] = $p2_custom_post_type; // sets the request post type to custom post type instead of the default 'Post'.
        return $data;
    }
    return $data;

}
// Add the filter
add_filter('wp_insert_post_data', 'redirect_xmlrpc_to_custom_post_type', 99, 2);