/*

 * Copyright (C) 2005 Frerich Raabe <raabe@kde.org>

 * Copyright (C) 2006, 2009 Apple Inc. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "config.h"

#include "XPathExpression.h"

#if ENABLE(XPATH)

#include "Document.h"

#include "PlatformString.h"

#include "XPathException.h"

#include "XPathExpressionNode.h"

#include "XPathNSResolver.h"

#include "XPathParser.h"

#include "XPathResult.h"

#include "XPathUtil.h"

namespace WebCore {

using namespace XPath;

PassRefPtr<XPathExpression> XPathExpression::createExpression(const String& expression, XPathNSResolver* resolver, ExceptionCode& ec)

{

    RefPtr<XPathExpression> expr = XPathExpression::create();

    Parser parser;

    expr->m_topExpression = parser.parseStatement(expression, resolver, ec);

    if (!expr->m_topExpression)

        return 0;

    return expr.release();

}

XPathExpression::~XPathExpression()

{

    delete m_topExpression;

}

PassRefPtr<XPathResult> XPathExpression::evaluate(Node* contextNode, unsigned short type, XPathResult*, ExceptionCode& ec)

{

    if (!isValidContextNode(contextNode)) {

        ec = NOT_SUPPORTED_ERR;

        return 0;

    }

    EvaluationContext& evaluationContext = Expression::evaluationContext();

    evaluationContext.node = contextNode;

    evaluationContext.size = 1;

    evaluationContext.position = 1;

    evaluationContext.hadTypeConversionError = false;

    RefPtr<XPathResult> result = XPathResult::create(contextNode->document(), m_topExpression->evaluate());

    evaluationContext.node = 0; // Do not hold a reference to the context node, as this may prevent the whole document from being destroyed in time.

    if (evaluationContext.hadTypeConversionError) {

        // It is not specified what to do if type conversion fails while evaluating an expression, and INVALID_EXPRESSION_ERR is not exactly right

        // when the failure happens in an otherwise valid expression because of a variable. But XPathEvaluator does not support variables, so it's close enough.

        ec = XPathException::INVALID_EXPRESSION_ERR;

        return 0;

    }

    if (type != XPathResult::ANY_TYPE) {

        ec = 0;

        result->convertTo(type, ec);

        if (ec)

            return 0;

    }

    return result;

}

}

#endif // ENABLE(XPATH)