Real Time Data

[jmbnyc74]

I would like to get access to data from a messaging system
that is not JMS. I thought that it was possible to create your own
Data Service or Data Provider (I saw this in some Adobe Flex 2
manual, but it claimed that the info was in another forthcoming
manual). If this is possible where is the info on how to build a
non JMS provider.

[aglosband]

I think this section of the livedocs has what you are looking
for:




http://livedocs.macromedia.com/flex/2/docs/wwhelp/wwhimpl/common/html/wwhelp.htm?context=LiveDocs_Pa...



Hope that helps.

[jmbnyc74]

Thanks. That is close, but not exactly. What I want to do is
establish communication (from a flex 2 app) with a backend
messaging service (the API is SOAP, so no problem sending to it).
However, I want to get async callbacks when events arrive from the
messaging service. It is not clear from the doc (perhaps I need to
read the java docs more thoroughly) how the invoke method is called
(from where and when).

[aglosband]

Hi. The invoke method is called by the flex messaging system
(I believe by the message broker) when a message is received from a
flex client. This is where I think you would call into your backend
messaging service. You would then need to have a method setup to
receive the async callbacks from your messaging service and it is
here that you would push the messages back out to your flex clients
using what's shown in the invoke method in the doc.



MessageService msgService = (MessageService)service;

msgService.pushMessageToClients(message, true);

msgService.sendPushMessageFromPeer(message, true);



Does that make sense? Also, in the example from doc, the
service object that is used is defined in the ServiceAdapter class
which your custom adapter class will inherit from. I'm not sure if
that was clear.

[jvroom]

The code that Alex shows is what you would use if you write a
custom MessageAdapter. That allows you to process messages sent
from the client and alter the way in which those messages are
handled. In your case though, it sounds like you simply need to
push messages to clients by routing them from some other message
source. In this case, you can have your clients subscribe to
particular destinations with/without subtopics or selectors as
needed to control the routing. Then use the MessageBroker api on
the server to send these messages to the proper clients. See the
Feed.java file which is in the samples WAR file
WEB-INF/src/samples/dashboard/Feed.java.