RPC Service

RPC Service stands for "Remote Procedure Call" Service and is a common name used to identify a service that exposes an interface that can be called by remote programs in order to execute a procedure. An RPC Service tipically exposes one or more APIs (Application programming interface), permitting remote clients to make requests to the available methods and receive a proper response. The interface itself is not bound to a specific programming language, but uses a standard data exchange protocol (tipically xml or json). PRADO provides TRpcService that makes developing a RPC server application an extremely easy task.

To use TRpcService, configure it in the application specification like following:

The example specifies a RPC service provider named stockquote which implements the getPrice RPC method in the provider class StockQuote,

class StockQuote { /** * @param string $symbol the symbol of the stock * @return float the stock price * @soapmethod */ public function getPrice($symbol) { ....return stock price for $symbol } /** * Register the available methods * @return the list of implemented methods */ public function registerMethods() { return array( 'getPrice' => array('method' => array($this, 'getPrice')), ); } }

PRADO already bundles two common protocols: TXmlRpcService and TJsonRpcService: requests made by clients using one of these protocol will be automatically resolved and will call the user-specified APIs.

Note: TXmlRpcService is based on PHP XML-RPC extension and thus requires the extension to be installed.

With the above simple code, we already finish a simple RPC service that allows other applications to query the price of a specific stock. A client needs to know the exact url of the service, the name of the method and the list of parameters needed by the method.

// Assuming we're using the json-rpc php library from http://jsonrpcphp.org/ require_once 'jsonRPCClient.php'; $client=new jsonRPCClient('http://path/to/index.php?rpc=stockquote'); echo $client->getPrice('IBM');