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diff --git a/sca-java-2.x/contrib/samples/learning-more/binding-comet/multiple-response-webapp/README b/sca-java-2.x/contrib/samples/learning-more/binding-comet/multiple-response-webapp/README deleted file mode 100644 index dc69bcf6fc..0000000000 --- a/sca-java-2.x/contrib/samples/learning-more/binding-comet/multiple-response-webapp/README +++ /dev/null @@ -1,100 +0,0 @@ -Tuscany - Learning More - Binding Comet - Weather Monitor Webapp ------------------------------------------------------------------ - -This sample demonstrates how Tuscany can expose services via Comet techniques -as well as how to interact with them using Tuscany's javascript toolkit. It -also demonstrates how to push multiple responses for a single request using -SCA callbacks via comet techniques. - -This project contains multiple services that once called will push notifications -to the client regarding certain weather parameters according to the location of -the user. Of course, the service implementation is a mock that generates random -numbers at a fixed interval of time as weather parameters. - -By adding <tuscany:binding.comet/> to a service definition, the Tuscany runtime -will handle the communication between the browser client and the service -implementation using Comet techniques. This enables bidirectional communication -over HTTP, therefore enabling server push. For more information, check -http://en.wikipedia.org/wiki/Comet_(programming). - -The comet binding is using the Atmosphere Framework under the hood to acomodate -as many deployment envorinments as possible. Basically, it checks if the -application server supports Servlet 3.0 falling back to a number of native -comet solutions provided by vendors (Jetty, Tomcat, WebLogic, GlassFish and -others). If none is available, Atmosphere will fallback to blocking IO. - -In order to enable callbacks to push multiple responses, you need to declare the -CometCallback in the service definition as follows: - <interface.java interface="org.apache.tuscany.sca.sample.comet.ChatService" - callbackInterface="org.apache.tuscany.sca.binding.comet.runtime.callback.CometCallback" /> - <tuscany:binding.comet /> - <callback> - <tuscany:binding.comet /> - </callback> - -The callback object has methods that facilitate sending messages back to the -calling client. It can be injected in the service implementation using the @Callback -annotation. - -One requirement that service methods have to meet to enable multiple response -support is that they have to be annotated with @OneWay to enable non-blocking -support. Without it, methods are treated synchronously sending a single response -which is the object returned by the method call. - -Invoking comet services can be done using Tuscany's javascript API which simulates -SCA in the browser. It uses the Atmosphere jQuery plugin under the hood. In order -to use it, the following script has to be included in the client page: - <script type="text/javascript" - src="tuscany-comet-js/org.apache.tuscany.sca.CometComponentContext.js"> - </script> - -The javascript toolkit permits choosing between two comet techniques: HTTP streaming -and long polling. More detailed information about them can be found on the previously -mentioned wikipedia page. - -First, a connect operation has to be issued in order to initiate communication -with the server side using the technique of your choice. This is done using the -connection method as follows: - SCA.TuscanyComet.connect('streaming'); // for HTTP streaming - SCA.TuscanyComet.connect('long-polling'); // for long polling - SCA.TuscanyComet.connect(); // starts with HTTP streaming and falls back to long polling if necessary - -The Tuscany Comet toolkit will inject proxies for all services defined in the composite -that are using binding.comet. All invocation and connection management is handled -under the hood so in order to invoke a comet service, the following should be called: - SCA.CometComponentContext.<service name>.<operation name>(<parameters>, callback); - -The callback parameter is the function that will handle responses received for a -certain service operation. It has a single argument which is the response: - function callback(response) { - // handle response - }; - -Note that the data exchange is automatically handled by the binding, so parameters -will be mapped to the data types defined in the method definition. Also, the response -will have the same data type as the server side object used to wrap the response. -Objects are passed over the wire in JSON format. - -Another detail worth mentioning is that the binding will use a single HTTP -connection to handle communication between a browser client and all services -defined using binding.comet in the same composite. Requests and responses will get -multiplexed via the same channel and get routed to the appropriate service -implementation, respectively javascript function. This is done in order to avoid -the 2 HTTP connection limit imposed by browsers. For more info, check -http://www.openajax.org/runtime/wiki/The_Two_HTTP_Connection_Limit_Issue. - -In order to run the sample, you can execute "mvn clean install t7:run" which will -start a Tomcat 7 instance automatically or use "mvn package" and deploy the resulting -war to the application server of your choice. - -Next, point your browser at - http://localhost:8080/sample-binding-comet-weather-webapp/ - -You can now set a location and register for various weather parameters. Notifications -will be pushed to the browser when weather parameters change. You can see the persistent -HTTP streaming connection or long polling subsequent connections using the developer -tools provided by your browser. - -The comet binding is an experimental binding so community feedback is much -appreciated. Feel free to send comments or suggestions on the Apache Tuscany -dev mailing list (dev@tuscany.apache.org).
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