/*
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright 2007-2008 Sun Microsystems, Inc. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can obtain
* a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
* or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
* Sun designates this particular file as subject to the "Classpath" exception
* as provided by Sun in the GPL Version 2 section of the License file that
* accompanied this code. If applicable, add the following below the License
* Header, with the fields enclosed by brackets [] replaced by your own
* identifying information: "Portions Copyrighted [year]
* [name of copyright owner]"
*
* Contributor(s):
*
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*
*/
/*
* Copyright 2009 Richard Zschech.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package org.atmosphere.gwt.client.impl;
import java.util.Collections;
import org.atmosphere.gwt.client.AtmosphereClient;
import org.atmosphere.gwt.client.AtmosphereClientException;
import org.atmosphere.gwt.client.AtmosphereListener;
import com.google.gwt.user.client.DOM;
import com.google.gwt.user.client.Element;
import com.google.gwt.user.client.rpc.SerializationException;
import com.google.gwt.user.client.rpc.StatusCodeException;
/**
* This class uses Opera's event-source element to stream events.<br/>
* http://my.opera.com/WebApplications/blog/show.dml/438711
*
* The main issue with Opera's implementation is that we can't detect connection events. To support this three event
* listeners are setup: one "s" for string messages, one "o" for the GWT serialized object messages, and the other "c"
* for connection events. The server sends the event "c" as soon as the connection is established and "d"
* when the connection is terminated. A connection timer is setup to detect initial connection errors. To detect
* subsequent connection failure it also sends a heart beat events "h" when no messages have been sent for a specified
* heart beat interval.
*
* @author Richard Zschech
*/
public class OperaEventSourceCometTransport extends BaseCometTransport {
private Element eventSource;
private boolean connected;
@Override
public void initiate(AtmosphereClient client, AtmosphereListener listener) {
super.initiate(client, listener);
eventSource = createEventSource(this);
}
@Override
public void connect(int connectionCount) {
DOM.setElementAttribute(eventSource, "src", getUrl(connectionCount));
}
@Override
public void disconnect() {
DOM.setElementAttribute(eventSource, "src", "");
super.disconnect();
if (connected) {
connected = false;
listener.onDisconnected();
}
}
private static native Element createEventSource(OperaEventSourceCometTransport client) /*-{
var eventSource = document.createElement("event-source");
var stringMessageHandler = $entry(function(event) {
client.@org.atmosphere.gwt.client.impl.OperaEventSourceCometTransport::onString(Ljava/lang/String;)(event.data);
});
eventSource.addEventListener("s", stringMessageHandler, false);
var objectMessageHandler = $entry(function(event) {
client.@org.atmosphere.gwt.client.impl.OperaEventSourceCometTransport::onObject(Ljava/lang/String;)(event.data);
});
eventSource.addEventListener("o", objectMessageHandler, false);
var connectionHandler = $entry(function(event) {
client.@org.atmosphere.gwt.client.impl.OperaEventSourceCometTransport::onConnection(Ljava/lang/String;)(event.data);
});
eventSource.addEventListener("c", connectionHandler, false);
return eventSource;
}-*/;
@SuppressWarnings("unused")
private void onString(String message) {
listener.onMessage(Collections.singletonList(HTTPRequestCometTransport.unescape(message)));
}
@SuppressWarnings("unused")
private void onObject(String message) {
try {
listener.onMessage(Collections.singletonList(parse(message)));
}
catch (SerializationException e) {
listener.onError(e, true);
}
}
@SuppressWarnings("unused")
private void onConnection(String message) {
if (message.startsWith("c")) {
connected = true;
String initParameters = message.substring(1);
try {
String[] params = initParameters.split(":");
connectionId = Integer.parseInt(params[1]);
listener.onConnected(Integer.parseInt(params[0]), connectionId);
}
catch (NumberFormatException e) {
listener.onError(new AtmosphereClientException("Unexpected init parameters: " + initParameters), true);
}
}
else if (message.startsWith("e")) {
disconnect();
String status = message.substring(1);
try {
int statusCode;
String statusMessage;
int index = status.indexOf(' ');
if (index == -1) {
statusCode = Integer.parseInt(status);
statusMessage = null;
}
else {
statusCode = Integer.parseInt(status.substring(0, index));
statusMessage = HTTPRequestCometTransport.unescape(status.substring(index + 1));
}
listener.onError(new StatusCodeException(statusCode, statusMessage), false);
}
catch (NumberFormatException e) {
listener.onError(new AtmosphereClientException("Unexpected status code: " + status), false);
}
}
else if (message.equals("d")) {
connected = false;
disconnect();
listener.onDisconnected();
}
else if (message.equals("h")) {
listener.onHeartbeat();
}
else {
listener.onError(new AtmosphereClientException("Unexpected connection status: " + message), true);
}
}
}