code: /*
   * 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.
   */
  /*
   * $Id$
   */
  
  package org.apache.xalan.xsltc.compiler;
  
  import org.apache.bcel.generic.ConstantPoolGen;
  import org.apache.bcel.generic.INVOKEINTERFACE;
  import org.apache.bcel.generic.INVOKESPECIAL;
  import org.apache.bcel.generic.INVOKEVIRTUAL;
  import org.apache.bcel.generic.InstructionList;
  import org.apache.bcel.generic.NEW;
  import org.apache.bcel.generic.PUSH;
  import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
  import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
  import org.apache.xalan.xsltc.compiler.util.Type;
  import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
  
  /**
   * @author Jacek Ambroziak
   * @author Santiago Pericas-Geertsen
   * @author Morten Jorgensen
   */
  final class Message extends Instruction {
      private boolean _terminate = false;
  
      public void parseContents(Parser parser) {
  	String termstr = getAttribute("terminate");
  	if (termstr != null) {
              _terminate = termstr.equals("yes");
  	}
  	parseChildren(parser);
      }
  
      public Type typeCheck(SymbolTable stable) throws TypeCheckError {
  	typeCheckContents(stable);
  	return Type.Void;
      }
  
      public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
  	final ConstantPoolGen cpg = classGen.getConstantPool();
  	final InstructionList il = methodGen.getInstructionList();
  
  	// Load the translet (for call to displayMessage() function)
  	il.append(classGen.loadTranslet());
  
          switch (elementCount()) {
              case 0:
                  il.append(new PUSH(cpg, ""));
              break;
              case 1:
                  SyntaxTreeNode child = (SyntaxTreeNode) elementAt(0);
                  if (child instanceof Text) {
                      il.append(new PUSH(cpg, ((Text) child).getText()));
                      break;
                  }
                  // falls through
              default:
                  // Push current output handler onto the stack
                  il.append(methodGen.loadHandler());
  
                  // Replace the current output handler by a ToXMLStream
                  il.append(new NEW(cpg.addClass(STREAM_XML_OUTPUT)));
                  il.append(methodGen.storeHandler());
  
                  // Push a reference to a StringWriter
                  il.append(new NEW(cpg.addClass(STRING_WRITER)));
                  il.append(DUP);
                  il.append(DUP);
                  il.append(new INVOKESPECIAL(
                      cpg.addMethodref(STRING_WRITER, "<init>", "()V")));
  
                  // Load ToXMLStream
                  il.append(methodGen.loadHandler());
                  il.append(new INVOKESPECIAL(
                      cpg.addMethodref(STREAM_XML_OUTPUT, "<init>",
                                       "()V")));
  
                  // Invoke output.setWriter(STRING_WRITER)
                  il.append(methodGen.loadHandler());
                  il.append(SWAP);
                  il.append(new INVOKEINTERFACE(
                      cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                                                "setWriter",
                                                "("+WRITER_SIG+")V"), 2));
  
                  // Invoke output.setEncoding("UTF-8")
                  il.append(methodGen.loadHandler());
                  il.append(new PUSH(cpg, "UTF-8"));   // other encodings?
                  il.append(new INVOKEINTERFACE(
                      cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                                                "setEncoding",
                                                "("+STRING_SIG+")V"), 2));
  
                  // Invoke output.setOmitXMLDeclaration(true)
                  il.append(methodGen.loadHandler());
                  il.append(ICONST_1);
                  il.append(new INVOKEINTERFACE(
                      cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                                                "setOmitXMLDeclaration",
                                                "(Z)V"), 2));
  
                  il.append(methodGen.loadHandler());
                  il.append(new INVOKEINTERFACE(
                      cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                                                "startDocument",
                                                "()V"), 1));
  
                  // Inline translation of contents
                  translateContents(classGen, methodGen);
  
                  il.append(methodGen.loadHandler());
                  il.append(new INVOKEINTERFACE(
                      cpg.addInterfaceMethodref(TRANSLET_OUTPUT_INTERFACE,
                                                "endDocument",
                                                "()V"), 1));
  
                  // Call toString() on StringWriter
                  il.append(new INVOKEVIRTUAL(
                      cpg.addMethodref(STRING_WRITER, "toString",
                                       "()" + STRING_SIG)));
  
                  // Restore old output handler
                  il.append(SWAP);
                  il.append(methodGen.storeHandler());
              break;
          }
  
  	// Send the resulting string to the message handling method
  	il.append(new INVOKEVIRTUAL(cpg.addMethodref(TRANSLET_CLASS,
  						     "displayMessage",
  						     "("+STRING_SIG+")V")));
  
  	// If 'terminate' attribute is set to 'yes': Instanciate a
  	// RunTimeException, but it on the stack and throw an exception
  	if (_terminate == true) {
  	    // Create a new instance of RunTimeException
  	    final int einit = cpg.addMethodref("java.lang.RuntimeException",
  					       "<init>",
  					       "(Ljava/lang/String;)V");
  	    il.append(new NEW(cpg.addClass("java.lang.RuntimeException")));
  	    il.append(DUP);
  	    il.append(new PUSH(cpg,"Termination forced by an " +
  			           "xsl:message instruction"));
  	    il.append(new INVOKESPECIAL(einit));
  	    il.append(ATHROW);
  	}
      }
  
  }
  