001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the "License");
007 * you may not use this file except in compliance with the License.
008 * You may obtain a copy of the License at
009 *
010 * http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018 /*
019 * $Id: When.java 468650 2006-10-28 07:03:30Z minchau $
020 */
021
022 package org.apache.xalan.xsltc.compiler;
023
024 import org.apache.xalan.xsltc.compiler.util.BooleanType;
025 import org.apache.xalan.xsltc.compiler.util.ClassGenerator;
026 import org.apache.xalan.xsltc.compiler.util.ErrorMsg;
027 import org.apache.xalan.xsltc.compiler.util.MethodGenerator;
028 import org.apache.xalan.xsltc.compiler.util.Type;
029 import org.apache.xalan.xsltc.compiler.util.TypeCheckError;
030 import org.apache.xalan.xsltc.compiler.util.Util;
031
032 /**
033 * @author Jacek Ambroziak
034 * @author Santiago Pericas-Geertsen
035 * @author Morten Jorgensen
036 */
037 final class When extends Instruction {
038
039 private Expression _test;
040 private boolean _ignore = false;
041
042 public void display(int indent) {
043 indent(indent);
044 Util.println("When");
045 indent(indent + IndentIncrement);
046 System.out.print("test ");
047 Util.println(_test.toString());
048 displayContents(indent + IndentIncrement);
049 }
050
051 public Expression getTest() {
052 return _test;
053 }
054
055 public boolean ignore() {
056 return(_ignore);
057 }
058
059 public void parseContents(Parser parser) {
060 _test = parser.parseExpression(this, "test", null);
061
062 // Ignore xsl:if when test is false (function-available() and
063 // element-available())
064 Object result = _test.evaluateAtCompileTime();
065 if (result != null && result instanceof Boolean) {
066 _ignore = !((Boolean) result).booleanValue();
067 }
068
069 parseChildren(parser);
070
071 // Make sure required attribute(s) have been set
072 if (_test.isDummy()) {
073 reportError(this, parser, ErrorMsg.REQUIRED_ATTR_ERR, "test");
074 }
075 }
076
077 /**
078 * Type-check this when element. The test should always be type checked,
079 * while we do not bother with the contents if we know the test fails.
080 * This is important in cases where the "test" expression tests for
081 * the support of a non-available element, and the <xsl:when> body contains
082 * this non-available element.
083 */
084 public Type typeCheck(SymbolTable stable) throws TypeCheckError {
085 // Type-check the test expression
086 if (_test.typeCheck(stable) instanceof BooleanType == false) {
087 _test = new CastExpr(_test, Type.Boolean);
088 }
089 // Type-check the contents (if necessary)
090 if (!_ignore) {
091 typeCheckContents(stable);
092 }
093
094 return Type.Void;
095 }
096
097 /**
098 * This method should never be called. An Otherwise object will explicitly
099 * translate the "test" expression and and contents of this element.
100 */
101 public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
102 final ErrorMsg msg = new ErrorMsg(ErrorMsg.STRAY_WHEN_ERR, this);
103 getParser().reportError(Constants.ERROR, msg);
104 }
105 }