/*

 * 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.xalan.internal.xsltc.compiler.util.BooleanType;

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 When extends Instruction {

    private Expression _test;

    private boolean _ignore = false;

    public void display(int indent) {

        indent(indent);

        Util.println("When");

        indent(indent + IndentIncrement);

        System.out.print("test ");

        Util.println(_test.toString());

        displayContents(indent + IndentIncrement);

    }

    public Expression getTest() {

        return _test;

    }

    public boolean ignore() {

        return(_ignore);

    }

    public void parseContents(Parser parser) {

        _test = parser.parseExpression(this, "test", null);

        // Ignore xsl:if when test is false (function-available() and

        // element-available())

        Object result = _test.evaluateAtCompileTime();

        if (result != null && result instanceof Boolean) {

            _ignore = !((Boolean) result).booleanValue();

        }

        parseChildren(parser);

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

        if (_test.isDummy()) {

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

        }

    }

    /**

     * Type-check this when element. The test should always be type checked,

     * while we do not bother with the contents if we know the test fails.

     * This is important in cases where the "test" expression tests for

     * the support of a non-available element, and the <xsl:when> body contains

     * this non-available element.

     */

    public Type typeCheck(SymbolTable stable) throws TypeCheckError {

        // Type-check the test expression

        if (_test.typeCheck(stable) instanceof BooleanType == false) {

            _test = new CastExpr(_test, Type.Boolean);

        }

        // Type-check the contents (if necessary)

        if (!_ignore) {

            typeCheckContents(stable);

        }

        return Type.Void;

    }

    /**

     * This method should never be called. An Otherwise object will explicitly

     * translate the "test" expression and and contents of this element.

     */

    public void translate(ClassGenerator classGen, MethodGenerator methodGen) {

        final ErrorMsg msg = new ErrorMsg(ErrorMsg.STRAY_WHEN_ERR, this);

        getParser().reportError(Constants.ERROR, msg);

    }

}