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#include "Document.h"
31#include "ExceptionCode.h"
32#include "XPathException.h"
33#include "XPathExpressionNode.h"
34#include "XPathNSResolver.h"
35#include "XPathParser.h"
36#include "XPathResult.h"
37#include "XPathUtil.h"
38#include <wtf/text/WTFString.h>
39
40namespace WebCore {
41
42using namespace XPath;
43
44PassRefPtr<XPathExpression> XPathExpression::createExpression(const String& expression, XPathNSResolver* resolver, ExceptionCode& ec)
45{
46    RefPtr<XPathExpression> expr = XPathExpression::create();
47    Parser parser;
48
49    expr->m_topExpression = parser.parseStatement(expression, resolver, ec);
50    if (!expr->m_topExpression)
51        return 0;
52
53    return expr.release();
54}
55
56XPathExpression::~XPathExpression()
57{
58    delete m_topExpression;
59}
60
61PassRefPtr<XPathResult> XPathExpression::evaluate(Node* contextNode, unsigned short type, XPathResult*, ExceptionCode& ec)
62{
63    if (!isValidContextNode(contextNode)) {
64        ec = NOT_SUPPORTED_ERR;
65        return 0;
66    }
67
68    EvaluationContext& evaluationContext = Expression::evaluationContext();
69    evaluationContext.node = contextNode;
70    evaluationContext.size = 1;
71    evaluationContext.position = 1;
72    evaluationContext.hadTypeConversionError = false;
73    RefPtr<XPathResult> result = XPathResult::create(contextNode->document(), m_topExpression->evaluate());
74    evaluationContext.node = 0; // Do not hold a reference to the context node, as this may prevent the whole document from being destroyed in time.
75
76    if (evaluationContext.hadTypeConversionError) {
77        // It is not specified what to do if type conversion fails while evaluating an expression, and INVALID_EXPRESSION_ERR is not exactly right
78        // when the failure happens in an otherwise valid expression because of a variable. But XPathEvaluator does not support variables, so it's close enough.
79        ec = XPathException::INVALID_EXPRESSION_ERR;
80        return 0;
81    }
82
83    if (type != XPathResult::ANY_TYPE) {
84        ec = 0;
85        result->convertTo(type, ec);
86        if (ec)
87            return 0;
88    }
89
90    return result;
91}
92
93}
94