/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.tuscany.sca.binding.dwr;
import java.util.Collection;
import org.apache.tuscany.sca.core.invocation.MessageImpl;
import org.apache.tuscany.sca.interfacedef.Operation;
import org.apache.tuscany.sca.invocation.Invoker;
import org.apache.tuscany.sca.invocation.Message;
import org.directwebremoting.ScriptBuffer;
import org.directwebremoting.WebContext;
import org.directwebremoting.WebContextFactory;
import org.directwebremoting.proxy.dwr.Util;
public class DWRInvoker implements Invoker {
protected String referenceFunction;
public DWRInvoker(String referenceName, Operation operation) {
this.referenceFunction = referenceName + "." + operation.getName();
}
public Message invoke(Message requestMsg) {
invoke((Object[])requestMsg.getBody());
// DWR references can not return anything
return new MessageImpl();
}
public void invoke(Object[] args) {
// TODO: this only works if its the same thread as request
WebContext wctx = WebContextFactory.get();
String currentPage = wctx.getCurrentPage();
// Get a DWR Util proxy for all the browsers on the current page:
Collection sessions = wctx.getScriptSessionsByPage(currentPage);
Util utilAll = new Util(sessions);
ScriptBuffer referenceInvoke = getInvokeFragment(args, wctx);
// add the reference call to the Util proxy which will cause DWR to
// asynchronously send it to be run on each active browser client
utilAll.addScript(referenceInvoke);
}
/**
* Creates a fragment of JavaScript code to invoke the reference function
* Eg: "<referenceName>.<operationName>(arg1, arg2,...);"
*/
protected ScriptBuffer getInvokeFragment(Object[] args, WebContext wctx) {
ScriptBuffer sb = new ScriptBuffer();
sb.appendScript(referenceFunction);
sb.appendScript("(");
if (args != null) {
for (int i = 0; i < args.length; i++) {
sb.appendData(args[i]);
if (i < (args.length - 1)) {
sb.appendScript(", ");
}
}
}
sb.appendScript(");");
return sb;
}
}