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#include "private/qdeclarativexmllistmodel_p.h"

#include <qdeclarativecontext.h>

#include <qdeclarativeengine_p.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.

    For example, the following model has a role named "title", which can be accessed

    from the view's delegate:

    \qml

    XmlListModel {

        id: xmlModel

        ...

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

    }

    ListView {

        model: xmlModel

        delegate: Text { text: title }

    }

    \endqml

*/

/*!

    \qmlproperty string XmlRole::query

    The relative XPath expression query for this role. The query must be relative; it cannot start

    with a '/'.

    For example, if there is an XML document like this:

    \quotefile doc/src/snippets/declarative/xmlrole.xml

    Here are some valid XPath expressions for XmlRole queries on this document:

    \snippet doc/src/snippets/declarative/xmlrole.qml 0

    \dots 4

    \snippet doc/src/snippets/declarative/xmlrole.qml 1

    See the \l{http://www.w3.org/TR/xpath20/}{W3C XPath 2.0 specification} for more information.

*/

/*!

    \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;

    QList<void*> roleQueryErrorId; // the ptr to send back if there is an error

    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");

        m_currentJob.queryId = -1;

    }

    ~QDeclarativeXmlQuery() {

        m_mutex.lock();

        m_quit = true;

        m_condition.wakeOne();

        m_mutex.unlock();

        wait();

    }

    void abort(int id) {

        QMutexLocker locker(&m_mutex);

        QQueue<XmlQueryJob>::iterator it;

        for (it = m_jobs.begin(); it != m_jobs.end(); ++it) {

            if ((*it).queryId == id) {

                m_jobs.erase(it);

                return;

            }

        }

        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();

            job.roleQueryErrorId << static_cast<void*>(roleObjects->at(i));

            if (roleObjects->at(i)->isKey())

                job.keyRoleQueries << job.roleQueries.last();

        }

        m_jobs.enqueue(job);

        m_queryIds++;

        if (!isRunning())

            start(QThread::IdlePriority);

        else

            m_condition.wakeOne();

        return job.queryId;

    }

Q_SIGNALS:

    void queryCompleted(const QDeclarativeXmlQueryResult &);

    void error(void*, const QString&);

protected:

    void run() {

        while (!m_quit) {

            m_mutex.lock();

            if (!m_jobs.isEmpty())

                m_currentJob = m_jobs.dequeue();

            m_mutex.unlock();

            QDeclarativeXmlQueryResult r;

            if (m_currentJob.queryId != -1) {

                doQueryJob();

                doSubQueryJob();

                r.queryId = m_currentJob.queryId;

                r.size = m_size;

                r.data = m_modelData;

                r.inserted = m_insertedItemRanges;

                r.removed = m_removedItemRanges;

                r.keyRoleResultsCache = m_currentJob.keyRoleResultsCache;

            }

            m_mutex.lock();

            if (m_currentJob.queryId != -1 && m_abortQueryId != m_currentJob.queryId)

                emit queryCompleted(r);

            if (m_jobs.isEmpty())

                m_condition.wait(&m_mutex);

            m_currentJob.queryId = -1;

            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;

    XmlQueryJob m_currentJob;

    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_currentJob.queryId != -1);

    QString r;

    QXmlQuery query;

    QBuffer buffer(&m_currentJob.data);

    buffer.open(QIODevice::ReadOnly);

    query.bindVariable(QLatin1String("src"), &buffer);

    query.setQuery(m_currentJob.namespaces + m_currentJob.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") + m_currentJob.namespaces;

    QString prefix = QLatin1String("doc($inputDocument)/dummy:items") +

                     m_currentJob.query.mid(m_currentJob.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();

    }

    m_currentJob.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_currentJob.queryId != -1);

    const QStringList &keysQueries = m_currentJob.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_currentJob.queryId != -1);

    m_modelData.clear();

    QBuffer b(&m_currentJob.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 (m_currentJob.keyRoleResultsCache.isEmpty()) {

        m_insertedItemRanges << qMakePair(0, m_size);

    } else {

        if (keyRoleResults != m_currentJob.keyRoleResultsCache) {

            QStringList temp;

            for (int i=0; i<m_currentJob.keyRoleResultsCache.count(); i++) {

                if (!keyRoleResults.contains(m_currentJob.keyRoleResultsCache[i]))

                    addIndexToRangeList(&m_removedItemRanges, i);

                else 

                    temp << m_currentJob.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);

                }

            }

        }

    }

    m_currentJob.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 = m_currentJob.roleQueries;

    for (int i = 0; i < queries.size(); ++i) {

        QList<QVariant> resultList;

        if (!queries[i].isEmpty()) {

            subquery.setQuery(m_prefix + QLatin1String("(let $v := ") + queries[i] + QLatin1String(" return if ($v) then ") + queries[i] + QLatin1String(" else \"\")"));

            if (subquery.isValid()) {

                QXmlResultItems resultItems;

                subquery.evaluateTo(&resultItems);

                QXmlItem item(resultItems.next());

                while (!item.isNull()) {

                    resultList << item.toAtomicValue(); //### we used to trim strings

                    item = resultItems.next();

                }

            } else {

                emit error(m_currentJob.roleQueryErrorId.at(i), queries[i]);

            }

        }

        //### 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(">"), QLatin1String(">"));

                    s.replace(QLatin1String("&"), 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) {}

    void notifyQueryStarted(bool remoteSource) {

        Q_Q(QDeclarativeXmlListModel);

        progress = remoteSource ? 0.0 : 1.0;

        status = QDeclarativeXmlListModel::Loading;

        errorString.clear();

        emit q->progressChanged(progress);

        emit q->statusChanged(status);

    }

    bool isComponentComplete;

    QUrl src;

    QString xml;

    QString query;

    QString namespaces;

    int size;

    QList<int> roles;

    QStringList roleNames;

    int highestRole;

    QNetworkReply *reply;

    QDeclarativeXmlListModel::Status status;

    QString errorString;

    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);

    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();

}

/*!

    \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. It can be used as a data source

    for view elements (such as ListView, PathView, GridView) and other elements that interact with model

    data (such as \l Repeater).

    For example, if there is a XML document at http://www.mysite.com/feed.xml like this:

    \code

    <?xml version="1.0" encoding="utf-8"?>

    <rss version="2.0">

        ...

        <channel>

            <item>

                <title>A blog post</title>

                <pubDate>Sat, 07 Sep 2010 10:00:01 GMT</pubDate>

            </item>