To be accurate, that is not "synchronous" behavior, which is about impossible in Flex.
But it is a fine way to handle onData events, since sockets do not give you the AsyncToken to use for this, as do the RPC objects. Tracy ________________________________ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of e_baggg Sent: Thursday, December 07, 2006 8:03 AM To: [email protected] Subject: [flexcoders] Re: socket question David, We are able to have some synchronous behavior to sockets. What we do is assign a unique ID with each request the client sends, and when the server is done, it passes that id back. So to further illustrate your example: Client sends this: <getServerData id="1" data="yourData"/> The server would then send back: <yourData id="1">blahblahblah</yourData> <done id="1"> Then, on your onData() method, you can check all <done/> XML, get the ID, and then use that ID to look up a callback function that you registered with that ID. Basically, all of our requests go through a Command which implements the IResponder class, we register that class to a Singleton which holds all the callback with the "id"...and when we see "<done/>", we check to see if a callback is there and if so it calls it's method. This ensures that all the data is back we want. Even if your getServerData request returns multiple socket messages: <getServerData id="1" data="yourData"/> <yourData id="1">blahblahblah</yourData> <yourData id="1">blahblahblah22222</yourData> <yourData id="1">blahblahblah333333</yourData> <done id="1"> Hope this helps. -Kevin --- In [email protected] <mailto:flexcoders%40yahoogroups.com> , "David Buitenveld" <[EMAIL PROTECTED]> wrote: > > Hi all - > > I am creating a server interface, one of whose implementations > involves talking over a socket connection. I have a need for > synchronous behavior - I call an API method, say > getServerData(aParam), and I get back the result that I want. Not sure > what a good way to do this with sockets would be since the receive > data event makes them asynchronous in nature - can anyone point me > to a good tutorial, or provide a hint? > > Consider a made up example : > > class SocketServer implements Server > private var _lastResult:String; > > // client calls this method and expects a result passed back > public function getServerData(aParam:String): String { > _socket.addEventListener(ProgressEvent.SOCKET_DATA, onData); > connectToSocket(someHost, somePort); > > _lastResult null; > issueCommandViaSocket(aParam); > > // sit around until we get data > while (_lastResult == null) ; > return _lastResult; > } > > private function onData(e:ProgressEvent):void { > _lastResult= socket.readUTFBytes(socket.bytesAvailable); > } > > this works conceptually, except that the wait around part hangs the > app.. if I remove that, then I can get the return value and log it in > the onData method.. so, am I even on the right track here? Is there > some way to have actionscript pause or wait until the desired event > gets fired? > > thanks for any thoughts - > > david >
