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#include "qdynamiccontext_p.h"

#include "qpatternistlocale_p.h"

#include "qitem_p.h"

#include "qxmlquery_p.h"

#include "qxmlserializer_p.h"

#include "qxmlserializer.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

QXmlSerializerPrivate::QXmlSerializerPrivate(const QXmlQuery &query,

                                             QIODevice *outputDevice)

    : isPreviousAtomic(false),

      state(QXmlSerializer::BeforeDocumentElement),

      np(query.namePool().d),

      device(outputDevice),

      codec(QTextCodec::codecForMib(106)), /* UTF-8 */

      query(query)

{

    hasClosedElement.reserve(EstimatedTreeDepth);

    namespaces.reserve(EstimatedTreeDepth);

    nameCache.reserve(EstimatedNameCount);

    hasClosedElement.push(qMakePair(QXmlName(), true));

    /*

      We push the empty namespace such that first of all

      namespaceBinding() won't assert on an empty QStack,

      and such that the empty namespace is in-scope and

      that the code doesn't attempt to declare it.

      We push the XML namespace. Although we won't receive

      declarations for it, we may output attributes by that

      name.

    */

    QVector<QXmlName> defNss;

    defNss.resize(2);

    defNss[0] = QXmlName(StandardNamespaces::empty,

                         StandardLocalNames::empty,

                         StandardPrefixes::empty);

    defNss[1] = QXmlName(StandardNamespaces::xml,

                         StandardLocalNames::empty,

                         StandardPrefixes::xml);

    namespaces.push(defNss);

    /* If we don't set this flag, QTextCodec will generate a BOM. */

    converterState.flags = QTextCodec::IgnoreHeader;

}

/*!

  \class QXmlSerializer

  \brief The QXmlSerializer class is an implementation of QAbstractXmlReceiver for transforming XQuery output into unformatted XML.

  \reentrant

  \since 4.4

  \ingroup xml-tools

  QXmlSerializer translates an \l {XQuery Sequence} {XQuery sequence}, usually

  the output of an QXmlQuery, into XML. Consider the example:

  \snippet doc/src/snippets/code/src_xmlpatterns_api_qxmlserializer.cpp 0

  First it constructs a \l {QXmlQuery} {query} that gets the

  first paragraph from document \c index.html. Then it constructs

  an instance of this class with the \l {QXmlQuery} {query} and

  \l {QIODevice} {myOutputDevice}. Finally, it

  \l {QXmlQuery::evaluateTo()} {evaluates} the

  \l {QXmlQuery} {query}, producing an ordered sequence of calls

  to the serializer's callback functions. The sequence of callbacks

  transforms the query output to XML and writes it to

  \l {QIODevice} {myOutputDevice}.

  QXmlSerializer will:

  \list

  \o Declare namespaces when needed,

  \o Use appropriate escaping, when characters can't be

  represented in the XML,

  \o Handle line endings appropriately,

  \o Report errors, when it can't serialize the content, e.g.,

  when asked to serialize an attribute that is a top-level node,

  or when more than one top-level element is encountered.

  \endlist

  If an error occurs during serialization, result is undefined

  unless the serializer is driven through a call to

  QXmlQuery::evaluateTo().

  If the generated XML should be indented and formatted for reading,

  use QXmlFormatter.

  \sa {http://www.w3.org/TR/xslt-xquery-serialization/}{XSLT 2.0 and XQuery 1.0 Serialization}

  \sa QXmlFormatter

 */

/*!

  Constructs a serializer that uses the name pool and message

  handler in \a query, and writes the output to \a outputDevice.

  \a outputDevice must be a valid, non-null device that is open in

  write mode, otherwise behavior is undefined.

  \a outputDevice must not be opened with QIODevice::Text because it

  will cause the output to be incorrect. This class will ensure line

  endings are serialized as according with the XML specification.

  QXmlSerializer does not take ownership of \a outputDevice.

 */

QXmlSerializer::QXmlSerializer(const QXmlQuery &query,

                               QIODevice *outputDevice) : QAbstractXmlReceiver(new QXmlSerializerPrivate(query, outputDevice))

{

    if(!outputDevice)

    {

        qWarning("outputDevice cannot be null.");

        return;

    }

    if(!outputDevice->isWritable())

    {

        qWarning("outputDevice must be opened in write mode.");

        return;

    }

}

/*!

  \internal

 */

QXmlSerializer::QXmlSerializer(QAbstractXmlReceiverPrivate *d) : QAbstractXmlReceiver(d)

{

}

/*!

  \internal

 */

bool QXmlSerializer::atDocumentRoot() const

{

    Q_D(const QXmlSerializer);

    return d->state == BeforeDocumentElement ||

           (d->state == InsideDocumentElement && d->hasClosedElement.size() == 1);

}

/*!

  \internal

 */

void QXmlSerializer::startContent()

{

    Q_D(QXmlSerializer);

    if (!d->hasClosedElement.top().second) {

        d->write('>');

        d->hasClosedElement.top().second = true;

    }

}

/*!

  \internal

 */

void QXmlSerializer::writeEscaped(const QString &toEscape)

{

    if(toEscape.isEmpty()) /* Early exit. */

        return;

    QString result;

    result.reserve(int(toEscape.length() * 1.1));

    const int length = toEscape.length();

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

    {

        const QChar c(toEscape.at(i));

        if(c == QLatin1Char('<'))

            result += QLatin1String("<");

        else if(c == QLatin1Char('>'))

            result += QLatin1String(">");

        else if(c == QLatin1Char('&'))

            result += QLatin1String("&");

        else

            result += toEscape.at(i);

    }

    write(result);

}

/*!

  \internal

 */

void QXmlSerializer::writeEscapedAttribute(const QString &toEscape)

{

    if(toEscape.isEmpty()) /* Early exit. */

        return;

    QString result;

    result.reserve(int(toEscape.length() * 1.1));

    const int length = toEscape.length();

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

    {

        const QChar c(toEscape.at(i));

        if(c == QLatin1Char('<'))

            result += QLatin1String("<");

        else if(c == QLatin1Char('>'))

            result += QLatin1String(">");

        else if(c == QLatin1Char('&'))

            result += QLatin1String("&");

        else if(c == QLatin1Char('"'))

            result += QLatin1String(""");

        else

            result += toEscape.at(i);

    }

    write(result);

}

/*!

  \internal

 */

void QXmlSerializer::write(const QString &content)

{

    Q_D(QXmlSerializer);

    d->device->write(d->codec->fromUnicode(content.constData(), content.length(), &d->converterState));

}

/*!

  \internal

 */

void QXmlSerializer::write(const QXmlName &name)

{

    Q_D(QXmlSerializer);

    const QByteArray &cell = d->nameCache[name.code()];

    if(cell.isNull())

    {

        QByteArray &mutableCell = d->nameCache[name.code()];

        const QString content(d->np->toLexical(name));

        mutableCell = d->codec->fromUnicode(content.constData(),

                                            content.length(),

                                            &d->converterState);

        d->device->write(mutableCell);

    }

    else

        d->device->write(cell);

}

/*!

  \internal

 */

void QXmlSerializer::write(const char *const chars)

{

    Q_D(QXmlSerializer);

    d->device->write(chars);

}

/*!

  \reimp

 */

void QXmlSerializer::startElement(const QXmlName &name)

{

    Q_D(QXmlSerializer);

    Q_ASSERT(d->device);

    Q_ASSERT(d->device->isWritable());

    Q_ASSERT(d->codec);

    Q_ASSERT(!name.isNull());

    d->namespaces.push(QVector<QXmlName>());

    if(atDocumentRoot())

    {

        if(d->state == BeforeDocumentElement)

            d->state = InsideDocumentElement;

        else if(d->state != InsideDocumentElement)

        {

            d->query.d->staticContext()->error(QtXmlPatterns::tr(

               "Element %1 can't be serialized because it appears outside "

               "the document element.").arg(formatKeyword(d->np, name)),

                                               ReportContext::SENR0001,

                                               d->query.d->expression().data());

        }

    }

    startContent();

    d->write('<');

    write(name);

    /* Ensure that the namespace URI used in the name gets outputted. */

    namespaceBinding(name);

    d->hasClosedElement.push(qMakePair(name, false));

    d->isPreviousAtomic = false;

}

/*!

  \reimp

 */

void QXmlSerializer::endElement()

{

    Q_D(QXmlSerializer);

    const QPair<QXmlName, bool> e(d->hasClosedElement.pop());

    d->namespaces.pop();

    if(e.second)

    {

        write("</");

        write(e.first);

        d->write('>');

    }

    else

        write("/>");

    d->isPreviousAtomic = false;

}

/*!

  \reimp

 */

void QXmlSerializer::attribute(const QXmlName &name,

                               const QStringRef &value)

{

    Q_D(QXmlSerializer);

    Q_ASSERT(!name.isNull());

    /* Ensure that the namespace URI used in the name gets outputted. */

    {

        /* Since attributes doesn't pick up the default namespace, a

         * namespace declaration would cause trouble if we output it. */

        if(name.prefix() != StandardPrefixes::empty)

            namespaceBinding(name);

    }

    if(atDocumentRoot())

    {

        Q_UNUSED(d);

        d->query.d->staticContext()->error(QtXmlPatterns::tr(

           "Attribute %1 can't be serialized because it appears at "

           "the top level.").arg(formatKeyword(d->np, name)),

                                           ReportContext::SENR0001,

                                           d->query.d->expression().data());

    }

    else

    {

        d->write(' ');

        write(name);

        write("=\"");

        writeEscapedAttribute(value.toString());

        d->write('"');

    }

}

/*!

  \internal

 */

bool QXmlSerializer::isBindingInScope(const QXmlName nb) const

{

    Q_D(const QXmlSerializer);

    const int levelLen = d->namespaces.size();

    if(nb.prefix() == StandardPrefixes::empty)

    {

        for(int lvl = levelLen - 1; lvl >= 0; --lvl)

        {

            const QVector<QXmlName> &scope = d->namespaces.at(lvl);

            const int vectorLen = scope.size();

            for(int s = vectorLen - 1; s >= 0; --s)

            {

                const QXmlName &nsb = scope.at(s);

                if(nsb.prefix() == StandardPrefixes::empty)

                    return nsb.namespaceURI() == nb.namespaceURI();

            }

        }

    }

    else

    {

        for(int lvl = 0; lvl < levelLen; ++lvl)

        {

            const QVector<QXmlName> &scope = d->namespaces.at(lvl);

            const int vectorLen = scope.size();

            for(int s = 0; s < vectorLen; ++s)

            {

                const QXmlName &n = scope.at(s);

                if (n.prefix() == nb.prefix() &&

                    n.namespaceURI() == nb.namespaceURI())

                    return true;

            }

        }

    }

    return false;

}

/*!

 \reimp

 */

void QXmlSerializer::namespaceBinding(const QXmlName &nb)

{

    /*

     * Writes out \a nb.

     *

     * Namespace bindings aren't looked up in a cache, because

     * we typically receive very few.

     */

    Q_D(QXmlSerializer);

    Q_ASSERT_X(!nb.isNull(), Q_FUNC_INFO,

               "It makes no sense to pass a null QXmlName.");

    Q_ASSERT_X((nb.namespaceURI() != StandardNamespaces::empty) ||

               (nb.prefix() == StandardPrefixes::empty),

               Q_FUNC_INFO,

               "Undeclarations of prefixes aren't allowed in XML 1.0 "

               "and aren't supposed to be received.");

    if(nb.namespaceURI() == QPatternist::StandardNamespaces::StopNamespaceInheritance)

        return;

    if(isBindingInScope(nb))

        return;

    d->namespaces.top().append(nb);

    if(nb.prefix() == StandardPrefixes::empty)

        write(" xmlns");

    else

    {

        write(" xmlns:");

        write(d->np->stringForPrefix(nb.prefix()));

    }

    write("=\"");

    writeEscapedAttribute(d->np->stringForNamespace(nb.namespaceURI()));

    d->write('"');

}

/*!

 \reimp

 */

void QXmlSerializer::comment(const QString &value)

{

    Q_D(QXmlSerializer);

    Q_ASSERT_X(!value.contains(QLatin1String("--")),

               Q_FUNC_INFO,

               "Invalid input; it's the caller's responsibility to ensure "

               "the input is correct.");

    startContent();

    write("<!--");

    write(value);

    write("-->");

    d->isPreviousAtomic = false;

}

/*!

 \reimp

 */

void QXmlSerializer::characters(const QStringRef &value)

{

    Q_D(QXmlSerializer);

    d->isPreviousAtomic = false;

    startContent();

    writeEscaped(value.toString());

}

/*!

 \reimp

 */

void QXmlSerializer::processingInstruction(const QXmlName &name,

                                           const QString &value)

{

    Q_D(QXmlSerializer);

    Q_ASSERT_X(!value.contains(QLatin1String("?>")),

               Q_FUNC_INFO,

               "Invalid input; it's the caller's responsibility to ensure "

               "the input is correct.");

    startContent();

    write("<?");

    write(name);

    d->write(' ');

    write(value);