diff -r 000000000000 -r 1918ee327afb src/xmlpatterns/api/qvariableloader.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/xmlpatterns/api/qvariableloader.cpp	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,264 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtXmlPatterns module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** 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
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QVariant>
+#include <QStringList>
+
+#include "qanyuri_p.h"
+#include "qatomicstring_p.h"
+#include "qbuiltintypes_p.h"
+#include "qcommonsequencetypes_p.h"
+#include "qgenericsequencetype_p.h"
+#include "qinteger_p.h"
+#include "qitem_p.h"
+#include "qsequencetype_p.h"
+#include "qvariableloader_p.h"
+#include "qxmlquery_p.h"
+
+QT_BEGIN_NAMESPACE
+
+namespace QPatternist
+{
+
+    class VariantListIterator : public ListIteratorPlatform<QVariant, Item, VariantListIterator>
+    {
+    public:
+        inline VariantListIterator(const QVariantList &list) : ListIteratorPlatform<QVariant, Item, VariantListIterator>(list)
+        {
+        }
+
+    private:
+        friend class ListIteratorPlatform<QVariant, Item, VariantListIterator>;
+
+        inline Item inputToOutputItem(const QVariant &inputType) const
+        {
+            return AtomicValue::toXDM(inputType);
+        }
+    };
+
+    class StringListIterator : public ListIteratorPlatform<QString, Item, StringListIterator>
+    {
+    public:
+        inline StringListIterator(const QStringList &list) : ListIteratorPlatform<QString, Item, StringListIterator>(list)
+        {
+        }
+
+    private:
+        friend class ListIteratorPlatform<QString, Item, StringListIterator>;
+
+        static inline Item inputToOutputItem(const QString &inputType)
+        {
+            return AtomicString::fromValue(inputType);
+        }
+    };
+
+    /**
+     * Takes two DynamicContext instances, and redirects the storage of temporary trees
+     * to one of them.
+     *
+     * @since 4.5
+     */
+    class TemporaryTreesRedirectingContext : public DelegatingDynamicContext
+    {
+    public:
+        TemporaryTreesRedirectingContext(const DynamicContext::Ptr &other,
+                                         const DynamicContext::Ptr &modelStorage) : DelegatingDynamicContext(other)
+                                                                                  , m_modelStorage(modelStorage)
+        {
+            Q_ASSERT(m_modelStorage);
+        }
+
+        virtual void addNodeModel(const QAbstractXmlNodeModel::Ptr &nodeModel)
+        {
+            m_modelStorage->addNodeModel(nodeModel);
+        }
+
+    private:
+        const DynamicContext::Ptr m_modelStorage;
+    };
+}
+
+using namespace QPatternist;
+
+SequenceType::Ptr VariableLoader::announceExternalVariable(const QXmlName name,
+                                                           const SequenceType::Ptr &declaredType)
+{
+    Q_UNUSED(declaredType);
+    const QVariant &variant = m_bindingHash.value(name);
+
+
+    if(variant.isNull())
+        return SequenceType::Ptr();
+    else if(variant.userType() == qMetaTypeId<QIODevice *>())
+        return CommonSequenceTypes::ExactlyOneAnyURI;
+    else if(variant.userType() == qMetaTypeId<QXmlQuery>())
+    {
+        const QXmlQuery variableQuery(qVariantValue<QXmlQuery>(variant));
+        return variableQuery.d->expression()->staticType();
+    }
+    else
+    {
+        return makeGenericSequenceType(AtomicValue::qtToXDMType(qVariantValue<QXmlItem>(variant)),
+                                       Cardinality::exactlyOne());
+    }
+}
+
+Item::Iterator::Ptr VariableLoader::evaluateSequence(const QXmlName name,
+                                                     const DynamicContext::Ptr &context)
+{
+
+    const QVariant &variant = m_bindingHash.value(name);
+    Q_ASSERT_X(!variant.isNull(), Q_FUNC_INFO,
+               "We assume that we have a binding.");
+
+    /* Same code as in the default clause below. */
+    if(variant.userType() == qMetaTypeId<QIODevice *>())
+        return makeSingletonIterator(itemForName(name));
+    else if(variant.userType() == qMetaTypeId<QXmlQuery>())
+    {
+        const QXmlQuery variableQuery(qVariantValue<QXmlQuery>(variant));
+
+        return variableQuery.d->expression()->evaluateSequence(DynamicContext::Ptr(new TemporaryTreesRedirectingContext(variableQuery.d->dynamicContext(), context)));
+    }
+
+    const QVariant v(qVariantValue<QXmlItem>(variant).toAtomicValue());
+
+    switch(v.type())
+    {
+        case QVariant::StringList:
+            return Item::Iterator::Ptr(new StringListIterator(v.toStringList()));
+        case QVariant::List:
+            return Item::Iterator::Ptr(new VariantListIterator(v.toList()));
+        default:
+            return makeSingletonIterator(itemForName(name));
+    }
+}
+
+Item VariableLoader::itemForName(const QXmlName &name) const
+{
+    const QVariant &variant = m_bindingHash.value(name);
+
+    if(variant.userType() == qMetaTypeId<QIODevice *>())
+        return Item(AnyURI::fromValue(QLatin1String("tag:trolltech.com,2007:QtXmlPatterns:QIODeviceVariable:") + m_namePool->stringForLocalName(name.localName())));
+
+    const QXmlItem item(qVariantValue<QXmlItem>(variant));
+
+    if(item.isNode())
+        return Item::fromPublic(item);
+    else
+    {
+        const QVariant atomicValue(item.toAtomicValue());
+        /* If the atomicValue is null it means it doesn't exist in m_bindingHash, and therefore it must
+         * be a QIODevice, since Patternist guarantees to only ask for variables that announceExternalVariable()
+         * has accepted. */
+        if(atomicValue.isNull())
+            return Item(AnyURI::fromValue(QLatin1String("tag:trolltech.com,2007:QtXmlPatterns:QIODeviceVariable:") + m_namePool->stringForLocalName(name.localName())));
+        else
+            return AtomicValue::toXDM(atomicValue);
+    }
+}
+
+Item VariableLoader::evaluateSingleton(const QXmlName name,
+                                       const DynamicContext::Ptr &)
+{
+    return itemForName(name);
+}
+
+bool VariableLoader::isSameType(const QVariant &v1,
+                                const QVariant &v2) const
+{
+    /* Are both of type QIODevice *? */
+    if(v1.userType() == qMetaTypeId<QIODevice *>() && v1.userType() == v2.userType())
+        return true;
+
+    /* Ok, we have two QXmlItems. */
+    const QXmlItem i1(qVariantValue<QXmlItem>(v1));
+    const QXmlItem i2(qVariantValue<QXmlItem>(v2));
+
+    if(i1.isNode())
+    {
+        Q_ASSERT(false);
+        return false;
+    }
+    else if(i2.isAtomicValue())
+        return i1.toAtomicValue().type() == i2.toAtomicValue().type();
+    else
+    {
+        /* One is an atomic, the other is a node or they are null. */
+        return false;
+    }
+}
+
+void VariableLoader::removeBinding(const QXmlName &name)
+{
+    m_bindingHash.remove(name);
+}
+
+bool VariableLoader::hasBinding(const QXmlName &name) const
+{
+    return m_bindingHash.contains(name)
+        || (m_previousLoader && m_previousLoader->hasBinding(name));
+}
+
+QVariant VariableLoader::valueFor(const QXmlName &name) const
+{
+    if(m_bindingHash.contains(name))
+        return m_bindingHash.value(name);
+    else if(m_previousLoader)
+        return m_previousLoader->valueFor(name);
+    else
+        return QVariant();
+}
+
+void VariableLoader::addBinding(const QXmlName &name,
+                                const QVariant &value)
+{
+    m_bindingHash.insert(name, value);
+}
+
+bool VariableLoader::invalidationRequired(const QXmlName &name,
+                                          const QVariant &variant) const
+{
+    return hasBinding(name) && !isSameType(valueFor(name), variant);
+}
+
+QT_END_NAMESPACE
+