/****************************************************************************

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** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

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** This file is part of the QtXmlPatterns module of the Qt Toolkit.

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** No Commercial Usage

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** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

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** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

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**

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****************************************************************************/

//

//  W A R N I N G

//  -------------

//

// This file is not part of the Qt API.  It exists purely as an

// implementation detail.  This header file may change from version to

// version without notice, or even be removed.

//

// We mean it.

#ifndef Patternist_XPathHelper_H

#define Patternist_XPathHelper_H

#include "qcommonnamespaces_p.h"

#include "qitem_p.h"

#include "qpatternistlocale_p.h"

#include "qreportcontext_p.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

namespace QPatternist

{

    /**

     * @short Contains helper and utility functions.

     *

     * The common denominator of its functions is that they do not fit in

     * well elsewhere, such as in a particular class. It is preferred if XPathHelper

     * goes away, and that functions are in more specific classes.

     *

     * @ingroup Patternist

     * @author Frans Englich <frans.englich@nokia.com>

     */

    class XPathHelper

    {

    public:

        /**

         * Determines whether @p qName is a valid QName. For example, "body" and "xhtml:body"

         * is, but "xhtml::body" or "x:body "(note the whitespace) is not.

         *

         * @see QNameConstructor::expandQName()

         * @see QNameValue

         */

        static bool isQName(const QString &qName);

        /**

         * @short Splits @p qName into @p localName and @p prefix.

         *

         * @note @p qName must be a valid QName, and that is not checked.

         */

        static void splitQName(const QString &qName, QString &prefix, QString &localName);

        /**

         * Determines whether @p ns is a reserved namespace.

         *

         * @see <a href="http://www.w3.org/TR/xslt20/#reserved-namespaces">XSL Transformations

         * (XSLT) Version 2.0, 3.2 Reserved Namespaces</a>

         * @see <a href="http://www.w3.org/TR/xquery/#FunctionDeclns">XQuery 1.0: An XML

         * Query Language, 4.15 Function Declaration</a>

         * @returns @c true if @p ns is a reserved namespace, otherwise @c false.

         */

        static bool isReservedNamespace(const QXmlName::NamespaceCode ns);

        /**

         * Determines whether @p collation is a supported string collation. If it is

         * not, error code @p code is raised via @p context.

         */

        template<const ReportContext::ErrorCode code, typename TReportContext>

        static inline void checkCollationSupport(const QString &collation,

                                                 const TReportContext &context,

                                                 const SourceLocationReflection *const r)

        {

            Q_ASSERT(context);

            Q_ASSERT(r);

            if(collation != QLatin1String(CommonNamespaces::UNICODE_COLLATION))

            {

                context->error(QtXmlPatterns::tr("Only the Unicode Codepoint "

                                  "Collation is supported(%1). %2 is unsupported.")

                                  .arg(formatURI(QLatin1String(CommonNamespaces::UNICODE_COLLATION)))

                                  .arg(formatURI(collation)),

                               code, r);

            }

        }

        static QPatternist::ItemTypePtr typeFromKind(const QXmlNodeModelIndex::NodeKind nodeKind);

        /**

         * Normalizes an @p uri by resolving it to the application directory if empty.

         */

        static QUrl normalizeQueryURI(const QUrl &uri);

        /**

         * @short Determines whether @p consists only of whitespace. Characters

         * considered whitespace are the ones for which QChar::isSpace() returns @c true for.

         *

         * For the empty string, @c true is returned.

         *

         * @returns @c true if @p string consists only of whitespace, otherwise @c false.

         */

        static inline bool isWhitespaceOnly(const QStringRef &string)

        {

            const int len = string.length();

            for(int i = 0; i < len; ++i)

            {

                if(!string.at(i).isSpace()) // TODO and this is wrong, see sdk/TODO

                    return false;

            }

            return true;

        }

        /**

         * @overload

         */

        static inline bool isWhitespaceOnly(const QString &string)

        {

            return isWhitespaceOnly(QStringRef(&string));

        }

    private:

        /**

         * @short This default constructor has no definition, in order to avoid

         * instantiation, since it makes no sense to instantiate this class.

         */

        inline XPathHelper();

        Q_DISABLE_COPY(XPathHelper)

    };

}

QT_END_NAMESPACE

QT_END_HEADER

#endif