qxmlquery.cpp

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** This file is part of the QtXmlPatterns module of the Qt Toolkit.
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** packaging of this file.  Please review the following information to
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#include <QtCore/QBuffer>
#include <QtCore/QStringList>
#include <QtXmlPatterns/QXmlFormatter>

#include "qacceltreeresourceloader_p.h"
#include "qcommonvalues_p.h"
#include "qxmlresultitems.h"
#include "qxmlresultitems_p.h"
#include "qxmlserializer.h"
#include "qxpathhelper_p.h"

#include "qxmlquery.h"
#include "qxmlquery_p.h"

QT_BEGIN_NAMESPACE

// ### Qt5: Merge constructor overloads
QXmlQuery::QXmlQuery() : d(new QXmlQueryPrivate())
{
}

QXmlQuery::QXmlQuery(const QXmlQuery &other) : d(new QXmlQueryPrivate(*other.d))
{
    /* First we have invoked QXmlQueryPrivate's synthesized copy constructor.
     * Keep this section in sync with QXmlQuery::operator=(). */
    d->detach();
}

QXmlQuery::QXmlQuery(const QXmlNamePool &np) : d(new QXmlQueryPrivate(np))
{
}

QXmlQuery::QXmlQuery(QueryLanguage queryLanguage,
                     const QXmlNamePool &np) : d(new QXmlQueryPrivate(np))
{
    d->queryLanguage = queryLanguage;
}

QXmlQuery::~QXmlQuery()
{
    delete d;
}

QXmlQuery &QXmlQuery::operator=(const QXmlQuery &other)
{
    /* Keep this section in sync with QXmlQuery::QXmlQuery(const QXmlQuery &).
     */
    if(d != other.d)
    {
        *d = *other.d;
        d->detach();
    }

    return *this;
}

void QXmlQuery::setMessageHandler(QAbstractMessageHandler *aMessageHandler)
{
    d->messageHandler = aMessageHandler;
}

QAbstractMessageHandler *QXmlQuery::messageHandler() const
{
    return d->messageHandler;
}

void QXmlQuery::setQuery(QIODevice *sourceCode, const QUrl &documentURI)
{
    if(!sourceCode)
    {
        qWarning("A null QIODevice pointer cannot be passed.");
        return;
    }

    if(!sourceCode->isReadable())
    {
        qWarning("The device must be readable.");
        return;
    }

    d->queryURI = QPatternist::XPathHelper::normalizeQueryURI(documentURI);
    d->expression(sourceCode);
}

void QXmlQuery::setQuery(const QString &sourceCode, const QUrl &documentURI)
{
    Q_ASSERT_X(documentURI.isEmpty() || documentURI.isValid(), Q_FUNC_INFO,
               "The document URI must be valid.");

    QByteArray query(sourceCode.toUtf8());
    QBuffer buffer(&query);
    buffer.open(QIODevice::ReadOnly);

    setQuery(&buffer, documentURI);
}

void QXmlQuery::setQuery(const QUrl &queryURI, const QUrl &baseURI)
{
    Q_ASSERT_X(queryURI.isValid(), Q_FUNC_INFO, "The passed URI must be valid.");

    const QUrl canonicalURI(QPatternist::XPathHelper::normalizeQueryURI(queryURI));
    Q_ASSERT(canonicalURI.isValid());
    Q_ASSERT(!canonicalURI.isRelative());
    Q_ASSERT(baseURI.isValid() || baseURI.isEmpty());

    d->queryURI = QPatternist::XPathHelper::normalizeQueryURI(baseURI.isEmpty() ? queryURI : baseURI);

    QPatternist::AutoPtr<QIODevice> result;

    try
    {
        result.reset(QPatternist::AccelTreeResourceLoader::load(canonicalURI, d->m_networkAccessDelegator,
                                                                d->staticContext()));
    }
    catch(const QPatternist::Exception)
    {
        /* We do nothing, result will be 0. */
    }

    if(result)
    {
        setQuery(result.data(), d->queryURI);
        result->close();
    }
    else
        d->recompileRequired();
}

void QXmlQuery::bindVariable(const QXmlName &name, const QXmlItem &value)
{
    if(name.isNull())
    {
        qWarning("The variable name cannot be null.");
        return;
    }

    const QPatternist::VariableLoader::Ptr vl(d->variableLoader());
    const QVariant variant(QVariant::fromValue(value));

    /* If the type of the variable changed(as opposed to only the value),
     * we will have to recompile. */
    if(vl->invalidationRequired(name, variant) || value.isNull())
        d->recompileRequired();

    vl->addBinding(name, variant);
}

void QXmlQuery::bindVariable(const QString &localName, const QXmlItem &value)
{
    bindVariable(QXmlName(d->namePool, localName), value);
}

void QXmlQuery::bindVariable(const QXmlName &name, QIODevice *device)
{
    if(device && !device->isReadable())
    {
        qWarning("A null, or readable QIODevice must be passed.");
        return;
    }

    if(name.isNull())
    {
        qWarning("The variable name cannot be null.");
        return;
    }

    const QPatternist::VariableLoader::Ptr vl(d->variableLoader());

    if(device)
    {
        const QVariant variant(QVariant::fromValue(device));

        if(vl->invalidationRequired(name, variant))
            d->recompileRequired();

        vl->addBinding(name, variant);

        /* We need to tell the resource loader to discard its document, because
         * the underlying QIODevice has changed, but the variable name is the
         * same which means that the URI is the same, and hence the resource
         * loader will return the document for the old QIODevice.
         */
        d->resourceLoader()->clear(QUrl(QLatin1String("tag:trolltech.com,2007:QtXmlPatterns:QIODeviceVariable:") + d->namePool.d->stringForLocalName(name.localName())));
    }
    else
    {
        vl->removeBinding(name);
        d->recompileRequired();
    }
}

void QXmlQuery::bindVariable(const QString &localName, QIODevice *device)
{
    bindVariable(QXmlName(d->namePool, localName), device);
}

bool QXmlQuery::evaluateTo(QAbstractXmlReceiver *callback) const
{
    if(!callback)
    {
        qWarning("A non-null callback must be passed.");
        return false;
    }

    if(isValid())
    {
        try
        {
            /*
             * This order is significant. expression() might cause
             * query recompilation, and as part of that it recreates
             * the static context. However, if we create the dynamic
             * context before the query recompilation has been
             * triggered, it will use the old static context, and
             * hence old source locations.
             */
            const QPatternist::Expression::Ptr expr(d->expression());
            const QPatternist::DynamicContext::Ptr dynContext(d->dynamicContext(callback));
            callback->startOfSequence();
            expr->evaluateToSequenceReceiver(dynContext);
            callback->endOfSequence();
            return true;
        }
        catch(const QPatternist::Exception)
        {
            return false;
        }
    }
    else
        return false;
}

bool QXmlQuery::evaluateTo(QStringList *target) const
{
    if(!target)
    {
        qWarning("A non-null callback must be passed.");
        return false;
    }

    if(isValid())
    {
        try
        {
            /*
             * This order is significant. expression() might cause
             * query recompilation, and as part of that it recreates
             * the static context. However, if we create the dynamic
             * context before the query recompilation has been
             * triggered, it will use the old static context, and
             * hence old source locations.
             */
            const QPatternist::Expression::Ptr expr(d->expression());
            if(!expr)
                return false;

            QPatternist::DynamicContext::Ptr dynContext(d->dynamicContext());

            if(!QPatternist::BuiltinTypes::xsString->xdtTypeMatches(expr->staticType()->itemType()))
                return false;

            const QPatternist::Item::Iterator::Ptr it(expr->evaluateSequence(dynContext));
            QPatternist::Item next(it->next());

            while(!next.isNull())
            {
                target->append(next.stringValue());
                next = it->next();
            }

            return true;
        }
        catch(const QPatternist::Exception)
        {
            return false;
        }
    }
    else
        return false;
}

bool QXmlQuery::evaluateTo(QIODevice *target) const
{
    if(!target)
    {
        qWarning("The pointer to the device cannot be null.");
        return false;
    }

    if(!target->isWritable())
    {
        qWarning("The device must be writable.");
        return false;
    }

    QXmlSerializer serializer(*this, target);
    return evaluateTo(&serializer);
}

void QXmlQuery::evaluateTo(QXmlResultItems *result) const
{
    if(!result)
    {
        qWarning("A null pointer cannot be passed.");
        return;
    }

    if(isValid())
    {
        try
        {
            /*
             * We don't have the d->expression() calls and
             * d->dynamicContext() calls in the same order as seen in
             * QXmlQuery::evaluateTo(), and the reason to why
             * that isn't a problem, is that we call isValid().
             */
            const QPatternist::DynamicContext::Ptr dynContext(d->dynamicContext());
            result->d_ptr->setDynamicContext(dynContext);
            result->d_ptr->iterator = d->expression()->evaluateSequence(dynContext);
        }
        catch(const QPatternist::Exception)
        {
            result->d_ptr->iterator = QPatternist::CommonValues::emptyIterator;
            result->d_ptr->hasError = true;
        }
    }
    else
    {
        result->d_ptr->iterator= QPatternist::CommonValues::emptyIterator;
        result->d_ptr->hasError = true;
    }
}

bool QXmlQuery::evaluateTo(QString *output) const
{
    Q_ASSERT_X(output, Q_FUNC_INFO,
               "The input cannot be null");

    QBuffer outputDevice;
    outputDevice.open(QIODevice::ReadWrite);

    QXmlFormatter formatter(*this, &outputDevice);
    const bool success = evaluateTo(&formatter);

    outputDevice.close();
    *output = QString::fromUtf8(outputDevice.data().constData());

    return success;
}

bool QXmlQuery::isValid() const
{
    return d->isValid();
}

void QXmlQuery::setUriResolver(const QAbstractUriResolver *resolver)
{
    d->uriResolver = resolver;
}

const QAbstractUriResolver *QXmlQuery::uriResolver() const
{
    return d->uriResolver;
}

QXmlNamePool QXmlQuery::namePool() const
{
    return d->namePool;
}

void QXmlQuery::setFocus(const QXmlItem &item)
{
    d->contextItem = item;
}

template<typename TInputType>
bool setFocusHelper(QXmlQuery *const queryInstance,
                    const TInputType &focusValue)
{
    /* We call resourceLoader(), so we have ensured that we have a resourceLoader
     * that we will share in our copy. */
    queryInstance->d->resourceLoader();

    QXmlQuery focusQuery(*queryInstance);

    /* Now we use the same, so we own the loaded document. */
    focusQuery.d->m_resourceLoader = queryInstance->d->m_resourceLoader;

    /* The copy constructor doesn't allow us to copy an existing QXmlQuery and
     * changing the language at the same time so we need to use private API. */
    focusQuery.d->queryLanguage = QXmlQuery::XQuery10;

    Q_ASSERT(focusQuery.queryLanguage() == QXmlQuery::XQuery10);
    focusQuery.bindVariable(QChar::fromLatin1('u'), focusValue);
    focusQuery.setQuery(QLatin1String("doc($u)"));
    Q_ASSERT(focusQuery.isValid());

    QXmlResultItems focusResult;

    queryInstance->d->m_resourceLoader = focusQuery.d->m_resourceLoader;

    focusQuery.evaluateTo(&focusResult);
    const QXmlItem focusItem(focusResult.next());

    if(focusItem.isNull() || focusResult.hasError())
    {
        /* The previous focus must be cleared in error situations.
         * Otherwise the query may be left in an inconsistent state. */
        queryInstance->setFocus(QXmlItem());
        return false;
    }
    else
    {
        queryInstance->setFocus(focusItem);
        return true;
    }
}

bool QXmlQuery::setFocus(const QUrl &documentURI)
{
    Q_ASSERT_X(documentURI.isValid() && !documentURI.isEmpty(),
               Q_FUNC_INFO,
               "The URI passed must be valid.");

    return setFocusHelper(this, QVariant(documentURI));
}

bool QXmlQuery::setFocus(QIODevice *document)
{
    if(!document)
    {
        qWarning("A null QIODevice pointer cannot be passed.");
        return false;
    }

    if(!document->isReadable())
    {
        qWarning("The device must be readable.");
        return false;
    }

    return setFocusHelper(this, document);
}

bool QXmlQuery::setFocus(const QString &focus)
{
    QBuffer device;
    device.setData(focus.toUtf8());
    device.open(QIODevice::ReadOnly);

    return setFocusHelper(this, &device);
}

QXmlQuery::QueryLanguage QXmlQuery::queryLanguage() const
{
    return d->queryLanguage;
}

void QXmlQuery::setInitialTemplateName(const QXmlName &name)
{
    d->initialTemplateName = name;
}

void QXmlQuery::setInitialTemplateName(const QString &localName)
{
    Q_ASSERT_X(QXmlName::isNCName(localName),
               Q_FUNC_INFO,
               "The name passed must be a valid NCName.");
    setInitialTemplateName(QXmlName(d->namePool, localName));
}

QXmlName QXmlQuery::initialTemplateName() const
{
    return d->initialTemplateName;
}

void QXmlQuery::setNetworkAccessManager(QNetworkAccessManager *newManager)
{
    d->m_networkAccessDelegator->m_genericManager = newManager;
}

QNetworkAccessManager *QXmlQuery::networkAccessManager() const
{
    return d->m_networkAccessDelegator->m_genericManager;
}

void QXmlQuery::bindVariable(const QXmlName &name, const QXmlQuery &query)
{
    Q_ASSERT_X(query.isValid(), Q_FUNC_INFO, "The query being bound must be valid.");

    const QPatternist::VariableLoader::Ptr vl(d->variableLoader());
    const QVariant variant(QVariant::fromValue(query));

    if(vl->invalidationRequired(name, variant))
        d->recompileRequired();

    vl->addBinding(name, variant);
}

void QXmlQuery::bindVariable(const QString &localName, const QXmlQuery &query)
{
    return bindVariable(QXmlName(d->namePool, localName), query);
}

QT_END_NAMESPACE