1 /*

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

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

     4  *

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

     6  * modification, are permitted provided that the following conditions

     7  * are met:

     8  * 

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

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

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

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

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

    14  * 

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

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

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

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

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

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

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

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

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

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

    25  */

    26 

    27 #include "config.h"

    28 #include "XPathExpression.h"

    29 

    30 #if ENABLE(XPATH)

    31 

    32 #include "Document.h"

    33 #include "PlatformString.h"

    34 #include "XPathException.h"

    35 #include "XPathExpressionNode.h"

    36 #include "XPathNSResolver.h"

    37 #include "XPathParser.h"

    38 #include "XPathResult.h"

    39 #include "XPathUtil.h"

    40 

    41 namespace WebCore {

    42 

    43 using namespace XPath;

    44     

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

    46 {

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

    48     Parser parser;

    49 

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

    51     if (!expr->m_topExpression)

    52         return 0;

    53 

    54     return expr.release();

    55 }

    56 

    57 XPathExpression::~XPathExpression()

    58 {

    59     delete m_topExpression;

    60 }

    61 

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

    63 {

    64     if (!isValidContextNode(contextNode)) {

    65         ec = NOT_SUPPORTED_ERR;

    66         return 0;

    67     }

    68 

    69     EvaluationContext& evaluationContext = Expression::evaluationContext();

    70     evaluationContext.node = contextNode;

    71     evaluationContext.size = 1;

    72     evaluationContext.position = 1;

    73     evaluationContext.hadTypeConversionError = false;

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

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

    76 

    77     if (evaluationContext.hadTypeConversionError) {

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

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

    80         ec = XPathException::INVALID_EXPRESSION_ERR;

    81         return 0;

    82     }

    83 

    84     if (type != XPathResult::ANY_TYPE) {

    85         ec = 0;

    86         result->convertTo(type, ec);

    87         if (ec)

    88             return 0;

    89     }

    90 

    91     return result;

    92 }

    93 

    94 }

    95 

    96 #endif // ENABLE(XPATH)