/*

 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * 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 com.sun.org.apache.xalan.internal.xsltc.compiler;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;

import com.sun.org.apache.bcel.internal.generic.INVOKEINTERFACE;

import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;

import com.sun.org.apache.bcel.internal.generic.InstructionList;

import com.sun.org.apache.bcel.internal.generic.PUSH;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ErrorMsg;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;

import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;

/**

 * @author Jacek Ambroziak

 * @author Santiago Pericas-Geertsen

 * @author Morten Jorgensen

 */

final class ValueOf extends Instruction {

    private Expression _select;

    private boolean _escaping = true;

    private boolean _isString = false;

    public void display(int indent) {

        indent(indent);

        Util.println("ValueOf");

        indent(indent + IndentIncrement);

        Util.println("select " + _select.toString());

    }

    public void parseContents(Parser parser) {

        _select = parser.parseExpression(this, "select", null);

        // make sure required attribute(s) have been set

        if (_select.isDummy()) {

            reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "select");

            return;

        }

        final String str = getAttribute("disable-output-escaping");

        if ((str != null) && (str.equals("yes"))) _escaping = false;

    }

    public Type typeCheck(SymbolTable stable) throws TypeCheckError {

        Type type = _select.typeCheck(stable);

        // Prefer to handle the value as a node; fall back to String, otherwise

        if (type != null && !type.identicalTo(Type.Node)) {

            /***

             *** %HZ% Would like to treat result-tree fragments in the same

             *** %HZ% way as node sets for value-of, but that's running into

             *** %HZ% some snags.  Instead, they'll be converted to String

            if (type.identicalTo(Type.ResultTree)) {

                _select = new CastExpr(new CastExpr(_select, Type.NodeSet),

                                       Type.Node);

            } else

            ***/

            if (type.identicalTo(Type.NodeSet)) {

                _select = new CastExpr(_select, Type.Node);

            } else {

                _isString = true;

                if (!type.identicalTo(Type.String)) {

                    _select = new CastExpr(_select, Type.String);

                }

                _isString = true;

            }

        }

        return Type.Void;

    }

    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {

        final ConstantPoolGen cpg = classGen.getConstantPool();

        final InstructionList il = methodGen.getInstructionList();

        final int setEscaping = cpg.addInterfaceMethodref(OUTPUT_HANDLER,

                                                          "setEscaping","(Z)Z");

        // Turn off character escaping if so is wanted.

        if (!_escaping) {

            il.append(methodGen.loadHandler());

            il.append(new PUSH(cpg,false));

            il.append(new INVOKEINTERFACE(setEscaping,2));

        }

        // Translate the contents.  If the value is a string, use the

        // translet.characters(String, TranslatOutputHandler) method.

        // Otherwise, the value is a node, and the

        // dom.characters(int node, TransletOutputHandler) method can dispatch

        // the string value of the node to the output handler more efficiently.

        if (_isString) {

            final int characters = cpg.addMethodref(TRANSLET_CLASS,

                                                    CHARACTERSW,

                                                    CHARACTERSW_SIG);

            il.append(classGen.loadTranslet());

            _select.translate(classGen, methodGen);

            il.append(methodGen.loadHandler());

            il.append(new INVOKEVIRTUAL(characters));

        } else {

            final int characters = cpg.addInterfaceMethodref(DOM_INTF,

                                                             CHARACTERS,

                                                             CHARACTERS_SIG);

            il.append(methodGen.loadDOM());

            _select.translate(classGen, methodGen);

            il.append(methodGen.loadHandler());

            il.append(new INVOKEINTERFACE(characters, 3));

        }

        // Restore character escaping setting to whatever it was.

        if (!_escaping) {

            il.append(methodGen.loadHandler());

            il.append(SWAP);

            il.append(new INVOKEINTERFACE(setEscaping,2));

            il.append(POP);

        }

    }

}