path: root/src/declarative/util/qdeclarativexmllistmodel.cpp

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#include "private/qdeclarativexmllistmodel_p.h"

#include <qdeclarativecontext.h>
#include <qdeclarativeengine.h>

#include <QDebug>
#include <QStringList>
#include <QQueue>
#include <QApplication>
#include <QThread>
#include <QMutex>
#include <QWaitCondition>
#include <QXmlQuery>
#include <QXmlResultItems>
#include <QXmlNodeModelIndex>
#include <QBuffer>
#include <QNetworkRequest>
#include <QNetworkReply>
#include <QTimer>

#include <private/qobject_p.h>

Q_DECLARE_METATYPE(QDeclarativeXmlQueryResult)

QT_BEGIN_NAMESPACE


typedef QPair<int, int> QDeclarativeXmlListRange;

#define XMLLISTMODEL_CLEAR_ID 0

/*!
    \qmlclass XmlRole QDeclarativeXmlListModelRole
  \since 4.7
    \brief The XmlRole element allows you to specify a role for an XmlListModel.

    \sa {QtDeclarative}
*/

/*!
    \qmlproperty string XmlRole::name
    The name for the role. This name is used to access the model data for this role from Qml.

    \qml
    XmlRole { name: "title"; query: "title/string()" }

    ...

    Component {
        id: myDelegate
        Text { text: title }
    }
    \endqml
*/

/*!
    \qmlproperty string XmlRole::query
    The relative XPath query for this role. The query should not start with a '/' (i.e. it must be
    relative).

    \qml
    XmlRole { name: "title"; query: "title/string()" }
    \endqml
*/

/*!
    \qmlproperty bool XmlRole::isKey
    Defines whether this is a key role.
    
    Key roles are used to to determine whether a set of values should
    be updated or added to the XML list model when XmlListModel::reload()
    is called.

    \sa XmlListModel
*/

struct XmlQueryJob
{
    int queryId;
    QByteArray data;
    QString query;
    QString namespaces;
    QStringList roleQueries;
    QStringList keyRoleQueries;
    QStringList keyRoleResultsCache;
};


class QDeclarativeXmlQuery : public QThread
{
    Q_OBJECT
public:
    QDeclarativeXmlQuery(QObject *parent=0)
        : QThread(parent), m_quit(false), m_abortQueryId(-1), m_queryIds(XMLLISTMODEL_CLEAR_ID + 1) {
        qRegisterMetaType<QDeclarativeXmlQueryResult>("QDeclarativeXmlQueryResult");
    }

    ~QDeclarativeXmlQuery() {
        m_mutex.lock();
        m_quit = true;
        m_condition.wakeOne();
        m_mutex.unlock();

        wait();
    }

    void abort(int id) {
        QMutexLocker locker(&m_mutex);
        m_abortQueryId = id;
    }

    int doQuery(QString query, QString namespaces, QByteArray data, QList<QDeclarativeXmlListModelRole *> *roleObjects, QStringList keyRoleResultsCache) {
        QMutexLocker locker(&m_mutex);

        XmlQueryJob job;
        job.queryId = m_queryIds;
        job.data = data;
        job.query = QLatin1String("doc($src)") + query;
        job.namespaces = namespaces;
        job.keyRoleResultsCache = keyRoleResultsCache;

        for (int i=0; i<roleObjects->count(); i++) {
            if (!roleObjects->at(i)->isValid()) {
                job.roleQueries << QString();
                continue;
            }
            job.roleQueries << roleObjects->at(i)->query();
            if (roleObjects->at(i)->isKey())
                job.keyRoleQueries << job.roleQueries.last();
        }
        m_jobs.enqueue(job);
        m_queryIds++;

        if (!isRunning())
            start();
        else
            m_condition.wakeOne();
        return job.queryId;
    }

Q_SIGNALS:
    void queryCompleted(const QDeclarativeXmlQueryResult &);

protected:
    void run() {
        while (!m_quit) {
            m_mutex.lock();
            doQueryJob();
            doSubQueryJob();
            m_mutex.unlock();

            m_mutex.lock();
            const XmlQueryJob &job = m_jobs.dequeue();
            if (m_abortQueryId != job.queryId) {
                QDeclarativeXmlQueryResult r;
                r.queryId = job.queryId;
                r.size = m_size;
                r.data = m_modelData;
                r.inserted = m_insertedItemRanges;
                r.removed = m_removedItemRanges;
                r.keyRoleResultsCache = job.keyRoleResultsCache;
                emit queryCompleted(r);
            }
            if (m_jobs.isEmpty())
                m_condition.wait(&m_mutex);
            m_abortQueryId = -1;
            m_mutex.unlock();
        }
    }

private:
    void doQueryJob();
    void doSubQueryJob();
    void getValuesOfKeyRoles(QStringList *values, QXmlQuery *query) const;
    void addIndexToRangeList(QList<QDeclarativeXmlListRange> *ranges, int index) const;

private:
    QMutex m_mutex;
    QWaitCondition m_condition;
    QQueue<XmlQueryJob> m_jobs;
    bool m_quit;
    int m_abortQueryId;
    QString m_prefix;
    int m_size;
    int m_queryIds;
    QList<QList<QVariant> > m_modelData;
    QList<QDeclarativeXmlListRange> m_insertedItemRanges;
    QList<QDeclarativeXmlListRange> m_removedItemRanges;
};

Q_GLOBAL_STATIC(QDeclarativeXmlQuery, globalXmlQuery)

void QDeclarativeXmlQuery::doQueryJob()
{
    Q_ASSERT(!m_jobs.isEmpty());
    XmlQueryJob &job = m_jobs.head();

    QString r;
    QXmlQuery query;
    QBuffer buffer(&job.data);
    buffer.open(QIODevice::ReadOnly);
    query.bindVariable(QLatin1String("src"), &buffer);
    query.setQuery(job.namespaces + job.query);
    query.evaluateTo(&r);

    //always need a single root element
    QByteArray xml = "<dummy:items xmlns:dummy=\"http://qtsotware.com/dummy\">\n" + r.toUtf8() + "</dummy:items>";
    QBuffer b(&xml);
    b.open(QIODevice::ReadOnly);

    QString namespaces = QLatin1String("declare namespace dummy=\"http://qtsotware.com/dummy\";\n") + job.namespaces;
    QString prefix = QLatin1String("doc($inputDocument)/dummy:items") +
                     job.query.mid(job.query.lastIndexOf(QLatin1Char('/')));

    //figure out how many items we are dealing with
    int count = -1;
    {
        QXmlResultItems result;
        QXmlQuery countquery;
        countquery.bindVariable(QLatin1String("inputDocument"), &b);
        countquery.setQuery(namespaces + QLatin1String("count(") + prefix + QLatin1Char(')'));
        countquery.evaluateTo(&result);
        QXmlItem item(result.next());
        if (item.isAtomicValue())
            count = item.toAtomicValue().toInt();
    }

    job.data = xml;
    m_prefix = namespaces + prefix + QLatin1Char('/');
    m_size = 0;
    if (count > 0)
        m_size = count;
}

void QDeclarativeXmlQuery::getValuesOfKeyRoles(QStringList *values, QXmlQuery *query) const
{
    Q_ASSERT(!m_jobs.isEmpty());

    const QStringList &keysQueries = m_jobs.head().keyRoleQueries;
    QString keysQuery;
    if (keysQueries.count() == 1)
        keysQuery = m_prefix + keysQueries[0];
    else if (keysQueries.count() > 1)
        keysQuery = m_prefix + QLatin1String("concat(") + keysQueries.join(QLatin1String(",")) + QLatin1String(")");

    if (!keysQuery.isEmpty()) {
        query->setQuery(keysQuery);
        QXmlResultItems resultItems;
        query->evaluateTo(&resultItems);
        QXmlItem item(resultItems.next());
        while (!item.isNull()) {
            values->append(item.toAtomicValue().toString());
            item = resultItems.next();
        }
    }
}

void QDeclarativeXmlQuery::addIndexToRangeList(QList<QDeclarativeXmlListRange> *ranges, int index) const {
    if (ranges->isEmpty())
        ranges->append(qMakePair(index, 1));
    else if (ranges->last().first + ranges->last().second == index)
        ranges->last().second += 1;
    else
        ranges->append(qMakePair(index, 1));
}

void QDeclarativeXmlQuery::doSubQueryJob()
{
    Q_ASSERT(!m_jobs.isEmpty());
    XmlQueryJob &job = m_jobs.head();
    m_modelData.clear();

    QBuffer b(&job.data);
    b.open(QIODevice::ReadOnly);

    QXmlQuery subquery;
    subquery.bindVariable(QLatin1String("inputDocument"), &b);

    QStringList keyRoleResults;
    getValuesOfKeyRoles(&keyRoleResults, &subquery);

    // See if any values of key roles have been inserted or removed.

    m_insertedItemRanges.clear();
    m_removedItemRanges.clear();
    if (job.keyRoleResultsCache.isEmpty()) {
        m_insertedItemRanges << qMakePair(0, m_size);
    } else {
        if (keyRoleResults != job.keyRoleResultsCache) {
            QStringList temp;
            for (int i=0; i<job.keyRoleResultsCache.count(); i++) {
                if (!keyRoleResults.contains(job.keyRoleResultsCache[i]))
                    addIndexToRangeList(&m_removedItemRanges, i);
                else 
                    temp << job.keyRoleResultsCache[i];
            }

            for (int i=0; i<keyRoleResults.count(); i++) {
                if (temp.count() == i || keyRoleResults[i] != temp[i]) {
                    temp.insert(i, keyRoleResults[i]);
                    addIndexToRangeList(&m_insertedItemRanges, i);
                }
            }
        }
    }
    job.keyRoleResultsCache = keyRoleResults;


    // Get the new values for each role.
    //### we might be able to condense even further (query for everything in one go)
    const QStringList &queries = job.roleQueries;
    for (int i = 0; i < queries.size(); ++i) {
        if (queries[i].isEmpty()) {
            QList<QVariant> resultList;
            for (int j = 0; j < m_size; ++j)
                resultList << QVariant();
            m_modelData << resultList;
            continue;
        }
        subquery.setQuery(m_prefix + QLatin1String("(let $v := ") + queries[i] + QLatin1String(" return if ($v) then ") + queries[i] + QLatin1String(" else \"\")"));
        QXmlResultItems resultItems;
        subquery.evaluateTo(&resultItems);
        QXmlItem item(resultItems.next());
        QList<QVariant> resultList;
        while (!item.isNull()) {
            resultList << item.toAtomicValue(); //### we used to trim strings
            item = resultItems.next();
        }
        //### should warn here if things have gone wrong.
        while (resultList.count() < m_size)
            resultList << QVariant();
        m_modelData << resultList;
        b.seek(0);
    }

    //this method is much slower, but works better for incremental loading
    /*for (int j = 0; j < m_size; ++j) {
        QList<QVariant> resultList;
        for (int i = 0; i < m_roleObjects->size(); ++i) {
            QDeclarativeXmlListModelRole *role = m_roleObjects->at(i);
            subquery.setQuery(m_prefix.arg(j+1) + role->query());
            if (role->isStringList()) {
                QStringList data;
                subquery.evaluateTo(&data);
                resultList << QVariant(data);
                //qDebug() << data;
            } else {
                QString s;
                subquery.evaluateTo(&s);
                if (role->isCData()) {
                    //un-escape
                    s.replace(QLatin1String("&lt;"), QLatin1String("<"));
                    s.replace(QLatin1String("&gt;"), QLatin1String(">"));
                    s.replace(QLatin1String("&amp;"), QLatin1String("&"));
                }
                resultList << s.trimmed();
                //qDebug() << s;
            }
            b.seek(0);
        }
        m_modelData << resultList;
    }*/
}

class QDeclarativeXmlListModelPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QDeclarativeXmlListModel)
public:
    QDeclarativeXmlListModelPrivate()
        : isComponentComplete(true), size(-1), highestRole(Qt::UserRole)
        , reply(0), status(QDeclarativeXmlListModel::Null), progress(0.0)
        , queryId(-1), roleObjects(), redirectCount(0) {}

    bool isComponentComplete;
    QUrl src;
    QString xml;
    QString query;
    QString namespaces;
    int size;
    QList<int> roles;
    QStringList roleNames;
    int highestRole;
    QNetworkReply *reply;
    QDeclarativeXmlListModel::Status status;
    qreal progress;
    int queryId;
    QStringList keyRoleResultsCache;
    QList<QDeclarativeXmlListModelRole *> roleObjects;
    static void append_role(QDeclarativeListProperty<QDeclarativeXmlListModelRole> *list, QDeclarativeXmlListModelRole *role);
    static void clear_role(QDeclarativeListProperty<QDeclarativeXmlListModelRole> *list);
    static void removeAt_role(QDeclarativeListProperty<QDeclarativeXmlListModelRole> *list, int i);
    static void insert_role(QDeclarativeListProperty<QDeclarativeXmlListModelRole> *list, int i, QDeclarativeXmlListModelRole *role);
    QList<QList<QVariant> > data;
    int redirectCount;
};


void QDeclarativeXmlListModelPrivate::append_role(QDeclarativeListProperty<QDeclarativeXmlListModelRole> *list, QDeclarativeXmlListModelRole *role)
{
    QDeclarativeXmlListModel *_this = qobject_cast<QDeclarativeXmlListModel *>(list->object);
    if (_this) {
        int i = _this->d_func()->roleObjects.count();
        _this->d_func()->roleObjects.append(role);
        if (_this->d_func()->roleNames.contains(role->name())) {
            qmlInfo(role) << QObject::tr("\"%1\" duplicates a previous role name and will be disabled.").arg(role->name());
            return;
        }
        _this->d_func()->roles.insert(i, _this->d_func()->highestRole);
        _this->d_func()->roleNames.insert(i, role->name());
        ++_this->d_func()->highestRole;
    }
}

//### clear needs to invalidate any cached data (in data table) as well
//    (and the model should emit the appropriate signals)
void QDeclarativeXmlListModelPrivate::clear_role(QDeclarativeListProperty<QDeclarativeXmlListModelRole> *list)
{
    QDeclarativeXmlListModel *_this = static_cast<QDeclarativeXmlListModel *>(list->object);
    _this->d_func()->roles.clear();
    _this->d_func()->roleNames.clear();
    _this->d_func()->roleObjects.clear();
}

/*!
    \class QDeclarativeXmlListModel
    \internal
*/

/*!
    \qmlclass XmlListModel QDeclarativeXmlListModel
  \since 4.7
    \brief The XmlListModel element is used to specify a model using XPath expressions.

    XmlListModel is used to create a model from XML data that can be used as a data source
    for the view classes (such as ListView, PathView, GridView) and other classes that interact with model
    data (such as Repeater).

    Here is an example of a model containing news from a Yahoo RSS feed:
    \qml
    XmlListModel {
        id: feedModel
        source: "http://rss.news.yahoo.com/rss/oceania"
        query: "/rss/channel/item"
        XmlRole { name: "title"; query: "title/string()" }
        XmlRole { name: "pubDate"; query: "pubDate/string()" }
        XmlRole { name: "description"; query: "description/string()" }
    }
    \endqml

    You can also define certain roles as "keys" so that the model only adds data
    that contains new values for these keys when reload() is called.

    For example, if the roles above were defined like this:

    \qml
        XmlRole { name: "title"; query: "title/string()"; isKey: true }
        XmlRole { name: "pubDate"; query: "pubDate/string()"; isKey: true }
    \endqml

    Then when reload() is called, the model will only add new items with a
    "title" and "pubDate" value combination that is not already present in
    the model.

    This is useful to provide incremental updates and avoid repainting an
    entire model in a view.

    \sa {QtDeclarative}
*/

QDeclarativeXmlListModel::QDeclarativeXmlListModel(QObject *parent)
    : QListModelInterface(*(new QDeclarativeXmlListModelPrivate), parent)
{
    connect(globalXmlQuery(), SIGNAL(queryCompleted(QDeclarativeXmlQueryResult)),
            this, SLOT(queryCompleted(QDeclarativeXmlQueryResult)));
}

QDeclarativeXmlListModel::~QDeclarativeXmlListModel()
{
}

/*!
    \qmlproperty list<XmlRole> XmlListModel::roles

    The roles to make available for this model.
*/
QDeclarativeListProperty<QDeclarativeXmlListModelRole> QDeclarativeXmlListModel::roleObjects()
{
    Q_D(QDeclarativeXmlListModel);
    QDeclarativeListProperty<QDeclarativeXmlListModelRole> list(this, d->roleObjects);
    list.append = &QDeclarativeXmlListModelPrivate::append_role;
    list.clear = &QDeclarativeXmlListModelPrivate::clear_role;
    return list;
}

QHash<int,QVariant> QDeclarativeXmlListModel::data(int index, const QList<int> &roles) const
{
    Q_D(const QDeclarativeXmlListModel);
    QHash<int, QVariant> rv;
    for (int i = 0; i < roles.size(); ++i) {
        int role = roles.at(i);
        int roleIndex = d->roles.indexOf(role);
        rv.insert(role, roleIndex == -1 ? QVariant() : d->data.value(roleIndex).value(index));
    }
    return rv;
}

QVariant QDeclarativeXmlListModel::data(int index, int role) const
{
    Q_D(const QDeclarativeXmlListModel);
    int roleIndex = d->roles.indexOf(role);
    return (roleIndex == -1) ? QVariant() : d->data.value(roleIndex).value(index);
}

/*!
    \qmlproperty int XmlListModel::count
    The number of data entries in the model.
*/
int QDeclarativeXmlListModel::count() const
{
    Q_D(const QDeclarativeXmlListModel);
    return d->size;
}

QList<int> QDeclarativeXmlListModel::roles() const
{
    Q_D(const QDeclarativeXmlListModel);
    return d->roles;
}

QString QDeclarativeXmlListModel::toString(int role) const
{
    Q_D(const QDeclarativeXmlListModel);
    int index = d->roles.indexOf(role);
    if (index == -1)
        return QString();
    return d->roleNames.at(index);
}

/*!
    \qmlproperty url XmlListModel::source
    The location of the XML data source.

    If both source and xml are set, xml will be used.
*/
QUrl QDeclarativeXmlListModel::source() const
{
    Q_D(const QDeclarativeXmlListModel);
    return d->src;
}

void QDeclarativeXmlListModel::setSource(const QUrl &src)
{
    Q_D(QDeclarativeXmlListModel);
    if (d->src != src) {
        d->src = src;
        if (d->xml.isEmpty())   // src is only used if d->xml is not set
            reload();
        emit sourceChanged();
   }
}

/*!
    \qmlproperty string XmlListModel::xml
    This property holds XML text set directly.

    The text is assumed to be UTF-8 encoded.

    If both source and xml are set, xml will be used.
*/
QString QDeclarativeXmlListModel::xml() const
{
    Q_D(const QDeclarativeXmlListModel);
    return d->xml;
}

void QDeclarativeXmlListModel::setXml(const QString &xml)
{
    Q_D(QDeclarativeXmlListModel);
    if (d->xml != xml) {
        d->xml = xml;
        reload();
        emit xmlChanged();
    }
}

/*!
    \qmlproperty string XmlListModel::query
    An absolute XPath query representing the base query for the model items. The query should start with
    '/' or '//'.
*/
QString QDeclarativeXmlListModel::query() const
{
    Q_D(const QDeclarativeXmlListModel);
    return d->query;
}

void QDeclarativeXmlListModel::setQuery(const QString &query)
{
    Q_D(QDeclarativeXmlListModel);
    if (!query.startsWith(QLatin1Char('/'))) {
        qmlInfo(this) << QCoreApplication::translate("QDeclarativeXmlRoleList", "An XmlListModel query must start with '/' or \"//\"");
        return;
    }

    if (d->query != query) {
        d->query = query;
        reload();
        emit queryChanged();
    }
}

/*!
    \qmlproperty string XmlListModel::namespaceDeclarations
    A set of declarations for the namespaces used in the query.
*/
QString QDeclarativeXmlListModel::namespaceDeclarations() const
{
    Q_D(const QDeclarativeXmlListModel);
    return d->namespaces;
}

void QDeclarativeXmlListModel::setNamespaceDeclarations(const QString &declarations)
{
    Q_D(QDeclarativeXmlListModel);
    if (d->namespaces != declarations) {
        d->namespaces = declarations;
        reload();
        emit namespaceDeclarationsChanged();
    }
}

/*!
    \qmlproperty enumeration XmlListModel::status
    Specifies the model loading status, which can be one of the following:

    \list
    \o XmlListModel.Null - No XML data has been set for this model.
    \o XmlListModel.Ready - The XML data has been loaded into the model.
    \o XmlListModel.Loading - The model is in the process of reading and loading XML data.
    \o XmlListModel.Error - An error occurred while the model was loading.
    \endlist

    \sa progress

*/
QDeclarativeXmlListModel::Status QDeclarativeXmlListModel::status() const
{
    Q_D(const QDeclarativeXmlListModel);
    return d->status;
}

/*!
    \qmlproperty real XmlListModel::progress

    This indicates the current progress of the downloading of the XML data
    source. This value ranges from 0.0 (no data downloaded) to
    1.0 (all data downloaded). If the XML data is not from a remote source,
    the progress becomes 1.0 as soon as the data is read.

    Note that when the progress is 1.0, the XML data has been downloaded, but 
    it is yet to be loaded into the model at this point. Use the status
    property to find out when the XML data has been read and loaded into
    the model.

    \sa status, source
*/
qreal QDeclarativeXmlListModel::progress() const
{
    Q_D(const QDeclarativeXmlListModel);
    return d->progress;
}

void QDeclarativeXmlListModel::classBegin()
{
    Q_D(QDeclarativeXmlListModel);
    d->isComponentComplete = false;
}

void QDeclarativeXmlListModel::componentComplete()
{
    Q_D(QDeclarativeXmlListModel);
    d->isComponentComplete = true;
    reload();
}

/*!
    \qmlmethod XmlListModel::reload()

    Reloads the model.
    
    If no key roles have been specified, all existing model
    data is removed, and the model is rebuilt from scratch.

    Otherwise, items are only added if the model does not already
    contain items with matching key role values.
    
    \sa XmlRole::isKey
*/
void QDeclarativeXmlListModel::reload()
{
    Q_D(QDeclarativeXmlListModel);

    if (!d->isComponentComplete)
        return;

    globalXmlQuery()->abort(d->queryId);
    d->queryId = -1;

    if (d->size < 0)
        d->size = 0;

    if (d->reply) {
        d->reply->abort();
        d->reply->deleteLater();
        d->reply = 0;
    }

    if (!d->xml.isEmpty()) {
        d->queryId = globalXmlQuery()->doQuery(d->query, d->namespaces, d->xml.toUtf8(), &d->roleObjects, d->keyRoleResultsCache);
        d->progress = 1.0;
        d->status = Loading;
        emit progressChanged(d->progress);
        emit statusChanged(d->status);
        return;
    }

    if (d->src.isEmpty()) {
        d->queryId = XMLLISTMODEL_CLEAR_ID;
        d->progress = 1.0;
        d->status = Loading;
        emit progressChanged(d->progress);
        emit statusChanged(d->status);
        QTimer::singleShot(0, this, SLOT(dataCleared()));
        return;
    }

    d->progress = 0.0;
    d->status = Loading;
    emit progressChanged(d->progress);
    emit statusChanged(d->status);

    QNetworkRequest req(d->src);
    d->reply = qmlContext(this)->engine()->networkAccessManager()->get(req);
    QObject::connect(d->reply, SIGNAL(finished()), this, SLOT(requestFinished()));
    QObject::connect(d->reply, SIGNAL(downloadProgress(qint64,qint64)),
                     this, SLOT(requestProgress(qint64,qint64)));
}

#define XMLLISTMODEL_MAX_REDIRECT 16

void QDeclarativeXmlListModel::requestFinished()
{
    Q_D(QDeclarativeXmlListModel);

    d->redirectCount++;
    if (d->redirectCount < XMLLISTMODEL_MAX_REDIRECT) {
        QVariant redirect = d->reply->attribute(QNetworkRequest::RedirectionTargetAttribute);
        if (redirect.isValid()) {
            QUrl url = d->reply->url().resolved(redirect.toUrl());
            d->reply->deleteLater();
            d->reply = 0;
            setSource(url);
            return;
        }
    }
    d->redirectCount = 0;

    if (d->reply->error() != QNetworkReply::NoError) {
        disconnect(d->reply, 0, this, 0);
        d->reply->deleteLater();
        d->reply = 0;

        int count = this->count();
        d->data.clear();
        d->size = 0;
        if (count > 0) {
            emit itemsRemoved(0, count);
            emit countChanged();
        }

        d->status = Error;
        d->queryId = -1;
        emit statusChanged(d->status);
    } else {
        QByteArray data = d->reply->readAll();
        if (data.isEmpty()) {
            d->queryId = XMLLISTMODEL_CLEAR_ID;
            QTimer::singleShot(0, this, SLOT(dataCleared()));
        } else {
            d->queryId = globalXmlQuery()->doQuery(d->query, d->namespaces, data, &d->roleObjects, d->keyRoleResultsCache);
        }
        disconnect(d->reply, 0, this, 0);
        d->reply->deleteLater();
        d->reply = 0;

        d->progress = 1.0;
        emit progressChanged(d->progress);
    }
}

void QDeclarativeXmlListModel::requestProgress(qint64 received, qint64 total)
{
    Q_D(QDeclarativeXmlListModel);
    if (d->status == Loading && total > 0) {
        d->progress = qreal(received)/total;
        emit progressChanged(d->progress);
    }
}

void QDeclarativeXmlListModel::dataCleared()
{
    Q_D(QDeclarativeXmlListModel);
    QDeclarativeXmlQueryResult r;
    r.queryId = XMLLISTMODEL_CLEAR_ID;
    r.size = 0;
    r.removed << qMakePair(0, count());
    r.keyRoleResultsCache = d->keyRoleResultsCache;
    queryCompleted(r);
}

void QDeclarativeXmlListModel::queryCompleted(const QDeclarativeXmlQueryResult &result)
{
    Q_D(QDeclarativeXmlListModel);
    if (result.queryId != d->queryId)
        return;

    int origCount = d->size;
    bool sizeChanged = result.size != d->size;

    d->size = result.size;
    d->data = result.data;
    d->keyRoleResultsCache = result.keyRoleResultsCache;
    d->status = Ready;
    d->queryId = -1;

    bool hasKeys = false;
    for (int i=0; i<d->roleObjects.count(); i++) {
        if (d->roleObjects[i]->isKey()) {
            hasKeys = true;
            break;
        }
    }
    if (!hasKeys) {
        if (!(origCount == 0 && d->size == 0)) {
            emit itemsRemoved(0, origCount);
            emit itemsInserted(0, d->size);
            emit countChanged();
        }

    } else {

        for (int i=0; i<result.removed.count(); i++)
            emit itemsRemoved(result.removed[i].first, result.removed[i].second);
        for (int i=0; i<result.inserted.count(); i++)
            emit itemsInserted(result.inserted[i].first, result.inserted[i].second);

        if (sizeChanged)
            emit countChanged();
    }

    emit statusChanged(d->status);
}

QT_END_NAMESPACE

#include <qdeclarativexmllistmodel.moc>