CNApi.php

<?php

class CNApi {
	public static function getServer() {
		// Returns the CNRestServer that will handle our API
		$server = new CNRestServer();
		
		// Bind all our API methods to it..
		$server->addMethod('misc.echo', array('CNApi', 'misc_echo'));
		
// Snipped
		
		return $server;
	}
	
	public static function misc_echo( $oauth_request ) {
		// A debug API method, returns whatever your call it with
		
		$params = $oauth_request->get_parameters();
		$rtn = array();
		foreach( $params AS $n => $p ) {
			if( substr($n, 0, 6) != 'oauth_' ) {
				$rtn[$n] = $p;
			}
		}
		return $rtn;
	}
}

CNRestServer.php

<?php

class CNRestServer {
	private $oauth_request = null;
	private $oauth_server = null;
	private $methods = array();
	
	public function __construct() {
		// Setup the OAuth library
		$hmac_method = new OAuthSignatureMethod_HMAC_SHA1();
		$plaintext_method = new OAuthSignatureMethod_PLAINTEXT();
	
		$this->oauth_server = new OAuthServer(new CNDataStorage());
		$this->oauth_server->add_signature_method($hmac_method);
		$this->oauth_server->add_signature_method($plaintext_method);
		
		$this->oauth_request = OAuthRequest::from_request();
	}
	
	public function addMethod( $name, $callback ) {
		// Add a new method to the server
		$this->methods[ $name ] = $callback;
	}
	
	public function handleCall() {
		// Handle a call
		
		list($consumer, $token) = $this->oauth_server->verify_request($this->oauth_request);
		// Verify OAuth call, and find the consumer and token in the call
		
		$method = $this->oauth_request->get_parameter('method');
		// Do we have a method to call
		if( !$method || !isset($this->methods[$method]) ) {
			// No or invalid method
			throw new Exception('Unknown method: ' . preg_replace('/[^-_.0-9a-zA-Z]/','',$method), 201);
		}
		$callback = $this->methods[ $method ];
		
		$user_table = new User_table();
		$user = $user_table->get( $token->userid, AF::DELAY_SAFE );
		// Finds the user tied to the token
		
		if( ! $user ) {
			// The user was somehow not found - this shouldn't be possible
			throw new Exception('Error trying to load user', 203);
		}
		
		if( $user->expired() ) {
			// The user has expired
			throw new Exception('This user account has expired', 301);
		}
		
		$params = $this->oauth_request->get_parameters();
		$params['oauth_request'] = $this->oauth_request;
		$params['consumer'] = $consumer;
		$params['token'] = $token;
		$params['user'] = $user;
		// Builds a list of parameters the requested method can use
		
		$args = $this->_sortArgs( $callback, $params );
		// Filter and sort the list by the parameters the method actually needs
		return call_user_func_array( $callback, $args );
	}
	
	protected function _sortArgs($callback, $params) {
		// Takes a callback and a list or params and filter and
		// sort the list by the parameters the method actually needs
		
        if( is_array($callback) ) {
            $ref_func = new ReflectionMethod($callback[0], $callback[1]);
        } else {
            $ref_func = new ReflectionFunction($callback);
        }
		// Create a reflection on the method
		
        $ref_parameters = $ref_func->getParameters();
		// finds the parameters needed for the function via Reflections
		
        $ordered_parameters = array();
        foreach($ref_parameters AS $ref_parameter) {
			// Run through all the parameters we need
			
            if( isset($params[$ref_parameter->getName()]) ) {
				// We have this parameters in the list to choose from
                $ordered_parameters[] = $params[$ref_parameter->getName()];
            } elseif( $ref_parameter->isDefaultValueAvailable() ) {
				// We don't have this parameter, but it's optional
                $ordered_parameters[] = $ref_parameter->getDefaultValue();
            } else {
				// We dont' have this parameter and it wasn't optional, abort!
            	throw new Exception('Missing parameter ' . $ref_parameter->getName() . '', 202);
                $ordered_parameters[] = null;
            }
        }
        return $ordered_parameters;
    }
}

example.php

<?php

    header("Content-Type: text/plain; charset=UTF-8");
    try {
      // Fetch the server
      $server = CNApi::getServer();

      // Ask the server to handle the call
      $output = $server->handleCall();
      
      // Return the output as JSON
      echo json_encode($output);
    } catch( Exception $e ) {
      // Something terrible happened
      header("HTTP/500 Internal Server Error"); // Check if this is how you do it!
      echo json_encode( array('error'=>1, 'msg'=>$e->getMessage(), 'code'=>$e->getCode()));
    }