Why is minimum_args protected?

Question

Why is $wp_xmlrpc_server->minimum_args protected? It seems like as much of a utility method as $wp_xmlrpc_server->login. Is there some other way to sanitize the inputs for length or do I have to write my own method?

Answer 1

You can totally swap out the class that runs the xmlrpc server. So create a subclass of wp_xmlrpc_server, use it for the xmlrpc server class, and use all the protected methods you like.

Example (not tested, use with caution):

<?php
class WPSE69959_XMLRPC_Sever extends wp_xmlrpc_server
{
    // override the constructor to add your own methods.
    public function __construct()
    {
        add_filter('xmlrpc_methods', array(__CLASS__, '_add_methods'));
        // call the parent constructor to set up the other methods
        parent::__construct();
    }

    public static function _add_methods($methods)
    {
        $methods['say_hello_two'] = 'this:say_hello_two';
        return $methods;
    }

    public function say_hello_two($args)
    {
        // do stuff with protected methods here!
    }
}

// swap out the classes
add_filter('wp_xmlrpc_server_class', 'wpse69959_swap_class');
function wpse69959_swap_class($cls)
{
    return 'WPSE69959_XMLRPC_Sever';
}

To answer your question, it's protected because it's meant to be an internal method. There would be no reason for someone outside the wp_xmlrpc_server class to use that method, so there's no reason for it to be public. Furthermore, the way it's implemented may cause unintentional side effects (like an error being set/sent) if it was used by an untrusted source -- eg. someone outside the wp_xmlrpc_server class.