Integrating Atmosphere with Grails

AtmosphereAndGrails

// Long-Polling is used in this example b/c of IE7

// Add atmosphere to ApplicationResources.groovy
modules = {
...
	atmosphere {
		dependsOn 'jquery'
		resource url:'js/atmosphere.js' // used jQuery atmosphere minified
	}
}

// ... in order to pull into GSP using
<g:javascript library="atmosphere" />

// BuildConfig.groovy
grails.tomcat.nio = true

dependencies {
		...
		compile 'org.atmosphere:atmosphere-runtime-native:2.1.0'
	}

// Config.groovy
Make sure atmosphere URL path is accessible via security settings

// web.xml
  <!-- Atmosphere servlet -->
	<servlet>
		<description>AtmosphereServlet</description>
		<servlet-name>AtmosphereServlet</servlet-name>
		<servlet-class>org.atmosphere.cpr.AtmosphereServlet</servlet-class>
		<init-param>
			<!-- A list, separated by comma, of package names to scan when looking for Atmosphere's annotations. -->
			<param-name>org.atmosphere.cpr.packages</param-name>
			<param-value>com.path.to.find.any.annotated.classes</param-value>
		</init-param>
		<load-on-startup>0</load-on-startup>
		<async-supported>true</async-supported>
	</servlet>

	<servlet-mapping>
		<servlet-name>AtmosphereServlet</servlet-name>
		<url-pattern>/atmourl/*</url-pattern>
	</servlet-mapping>

// All init-params available
http://atmosphere.github.io/atmosphere/apidocs/org/atmosphere/cpr/ApplicationConfig.html

// Added as a service, but also worked when added as a controller	
// @ManagedService - path should match URL pattern for defined atmosphere servlet in web.xml
// https://github.com/Atmosphere/atmosphere/wiki/Getting-Started-with-the-ManagedService-Annotation
  import org.atmosphere.config.service.Disconnect
  import org.atmosphere.config.service.ManagedService
  import org.atmosphere.config.service.Message
  import org.atmosphere.config.service.Ready
  import org.atmosphere.cpr.AtmosphereResource
  import org.atmosphere.cpr.AtmosphereResourceEvent
  
  @ManagedService(path = "/atmourl")
  class UiCommService {
  	
  	@Ready
  	public void onReady(final AtmosphereResource r) {
  		log.info("Browser {} connected.", r.uuid());
  	}
  
  	@Disconnect
  	public void onDisconnect(AtmosphereResourceEvent event) {
  		if (event.isCancelled()) {
  			log.info("Browser {} unexpectedly disconnected", event.getResource().uuid());
  		} else if (event.isClosedByClient()) {
  			log.info("Browser {} closed the connection", event.getResource().uuid());
  		}
  	}
  
  	//@org.atmosphere.config.service.Message(encoders = {JacksonEncoder.class}, decoders = {JacksonDecoder.class})
  	@org.atmosphere.config.service.Message
  	public Message onMessage(Message message) throws IOException {
  		log.info("{} just sent {}", message.getAuthor(), message.getMessage());
  		return message;
  	}

  }
	
// Broadcast from anywhere in code
	  // broadcast message to UI
		Broadcaster b = BroadcasterFactory.getDefault().lookup("/atmourl")
		log.debug("Broadcaster: " + b)
		log.debug("Atmo Resources: " + b.getAtmosphereResources())
		b.broadcast(msg)

// Embedded JS in GSP, or can be in separate JS file
// https://github.com/Atmosphere/atmosphere/wiki/jQuery.atmosphere.js-atmosphere.js-API
<g:javascript>
	var socket = $.atmosphere;
	var subSocket;
	var uicommUrl = document.location.protocol + '//' + document.location.hostname + ':' + document.location.port + '/context/atmourl';
	var request = {
	     url: uicommUrl,
	     contentType : "application/json",
	     //reconnectInterval: 1000,
	     timeout : 15000,
	     logLevel: 'error',
	     transport : "long-polling" ,
	     fallbackTransport: 'long-polling'};
	
	request.onOpen = function(response) {
		console.log("atmosphere onOpen " + response.transport)
		// Carry the UUID. This is required if you want to call subscribe(request) again.
		request.uuid = response.request.uuid;
	};
		 
	request.onClientTimeout = function(response) {
		console.log("atmosphere onClientTimeout")
	};
    
	request.onClose = function(response) {
	    console.log("atmosphere onClose")
	};
	
	request.onError = function(response) {
	    console.log("atmosphere onError")
	};
	
	request.onReconnect = function(request, response) {
	    console.log("atmosphere onReconnect")
	};

	request.onMessage = function (response) {
		console.log("atmosphere onMessage " + response.responseBody)
		$('div#divToAlterWithResponse').text(response.responseBody)
	};
	 
	subSocket = socket.subscribe(request);
</g:javascript>