Interceptors

Interceptors

With Interceptors, you can perform custom operations around the execution of remote communication, in both clients and services.

An interceptor is an object that implements the IHessianInterceptor interface and it has 2 main methods: beforeRequest and afterRequest . These methods accept a single HessianCallingContext as a parameter. This object contains different information pertaining the current action such as the method being called, url, original configuration options and the writer and parser objects that handle the protocol at a low level.

Check the source code for a complete description of the properties and methods in these two classes.

Configuration

Using interceptors is fairly simple.

1. Create a class that derives from IHessianInterceptor
2. Create an instance of the class
3. Add it to the interceptors array in the configuration options passed to HessianPHP clients or servers.

Example

This is a simple but useful interceptor that saves the binary streams involved in the communication and also the internal log of the parser activity.

class Interceptor implements IHessianInterceptor{
	
	function beforeRequest(HessianCallingContext $ctx){
		// the call property in the context is a HessianCall object
		// representing the RPC operation. We will log only if we are a client
		if($ctx->isClient)
			echo "Calling method: ".$ctx->call->method;
		else {
			$ipclient = $_SERVER['REMOTE_ADDR'];
		}
		// this tells the transport layer to save the original bytes
		$ctx->options->saveRaw = true; 
	}
	
	function afterRequest(HessianCallingContext $ctx){
		file_put_contents('outgoing.bin', $ctx->payload);
		file_put_contents('parserLog.txt', implode("\r\n", $ctx->parser->log));
		file_put_contents('writerLog.txt', implode("\r\n", $ctx->writer->log));
		file_put_contents('incoming.bin', $ctx->transport->rawData);
	}
}

// configuration
$interceptor = new Interceptor();

$options = new HessianOptions();
$options->interceptors = array($interceptor); // add interceptor 

$proxy = new HessianClient($url, $options);

// or

$server = new HessianService($testService, $options);

If you have diferent interceptors, they will execute in the order they were added to the array.