diff --git a/src/declarativeimports/core/datamodel.cpp b/src/declarativeimports/core/datamodel.cpp
index 50dc6c5e9..03bea207e 100644
--- a/src/declarativeimports/core/datamodel.cpp
+++ b/src/declarativeimports/core/datamodel.cpp
@@ -1,571 +1,574 @@
 /*
  *   Copyright 2010 by Marco Martin <mart@kde.org>
 
  *   This program is free software; you can redistribute it and/or modify
  *   it under the terms of the GNU Library General Public License as
  *   published by the Free Software Foundation; either version 2, or
  *   (at your option) any later version.
  *
  *   This program is distributed in the hope that it will be useful,
  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *   GNU General Public License for more details
  *
  *   You should have received a copy of the GNU Library General Public
  *   License along with this program; if not, write to the
  *   Free Software Foundation, Inc.,
  *   51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  */
 
 #include "datamodel.h"
 #include "datasource.h"
 
 #include <QQmlContext>
 #include <QQmlEngine>
 #include <QTimer>
 
 namespace Plasma
 {
 
 SortFilterModel::SortFilterModel(QObject *parent)
     : QSortFilterProxyModel(parent)
 {
     setObjectName(QStringLiteral("SortFilterModel"));
     setDynamicSortFilter(true);
     connect(this, SIGNAL(rowsInserted(QModelIndex,int,int)),
             this, SIGNAL(countChanged()));
     connect(this, SIGNAL(rowsRemoved(QModelIndex,int,int)),
             this, SIGNAL(countChanged()));
     connect(this, SIGNAL(modelReset()),
             this, SIGNAL(countChanged()));
     connect(this,  SIGNAL(countChanged()), this, SLOT(syncRoleNames()));
 }
 
 SortFilterModel::~SortFilterModel()
 {
 }
 
 void SortFilterModel::syncRoleNames()
 {
     if (!sourceModel()) {
         return;
     }
 
     m_roleIds.clear();
     const QHash<int, QByteArray> rNames = roleNames();
     m_roleIds.reserve(rNames.count());
     for (auto i = rNames.constBegin(); i != rNames.constEnd(); ++i) {
         m_roleIds[QString::fromUtf8(i.value())] = i.key();
     }
 
     setFilterRole(m_filterRole);
     setSortRole(m_sortRole);
 }
 
 QHash<int,QByteArray> SortFilterModel::roleNames() const
 {
-    return sourceModel()->roleNames();
+    if (sourceModel()) {
+       return sourceModel()->roleNames();
+    }
+    return {};
 }
 
 int SortFilterModel::roleNameToId(const QString &name) const
 {
     return m_roleIds.value(name, Qt::DisplayRole);
 }
 
 void SortFilterModel::setModel(QAbstractItemModel *model)
 {
     if (model == sourceModel()) {
         return;
     }
 
     if (sourceModel()) {
         disconnect(sourceModel(), SIGNAL(modelReset()), this, SLOT(syncRoleNames()));
     }
 
     QSortFilterProxyModel::setSourceModel(model);
 
     if (model) {
         connect(model, SIGNAL(modelReset()), this, SLOT(syncRoleNames()));
         syncRoleNames();
     }
 
     emit sourceModelChanged(model);
 }
 
 bool SortFilterModel::filterAcceptsRow(int source_row, const QModelIndex& source_parent) const
 {
     if (m_filterCallback.isCallable()) {
         QJSValueList args;
         args << QJSValue(source_row);
 
         const QModelIndex idx = sourceModel()->index(source_row, filterKeyColumn(), source_parent);
         QQmlEngine *engine = QQmlEngine::contextForObject(this)->engine();
         args << engine->toScriptValue<QVariant>(idx.data(m_roleIds.value(m_filterRole)));
 
         return const_cast<SortFilterModel *>(this)->m_filterCallback.call(args).toBool();
     }
 
     return QSortFilterProxyModel::filterAcceptsRow(source_row, source_parent);
 }
 
 void SortFilterModel::setFilterRegExp(const QString &exp)
 {
     if (exp == filterRegExp()) {
         return;
     }
     QSortFilterProxyModel::setFilterRegExp(QRegExp(exp, Qt::CaseInsensitive));
     Q_EMIT filterRegExpChanged(exp);
 }
 
 QString SortFilterModel::filterRegExp() const
 {
     return QSortFilterProxyModel::filterRegExp().pattern();
 }
 
 void SortFilterModel::setFilterString(const QString &filterString)
 {
     if (filterString == m_filterString) {
         return;
     }
     m_filterString = filterString;
     QSortFilterProxyModel::setFilterFixedString(filterString);
     Q_EMIT filterStringChanged(filterString);
 }
 
 QString SortFilterModel::filterString() const
 {
     return m_filterString;
 }
 
 QJSValue SortFilterModel::filterCallback() const
 {
     return m_filterCallback;
 }
 
 void SortFilterModel::setFilterCallback(const QJSValue& callback)
 {
     if (m_filterCallback.strictlyEquals(callback)) {
         return;
     }
 
     if (!callback.isNull() && !callback.isCallable()) {
         return;
     }
 
     m_filterCallback = callback;
     invalidateFilter();
 
     Q_EMIT filterCallbackChanged(callback);
 }
 
 void SortFilterModel::setFilterRole(const QString &role)
 {
     QSortFilterProxyModel::setFilterRole(roleNameToId(role));
     m_filterRole = role;
 }
 
 QString SortFilterModel::filterRole() const
 {
     return m_filterRole;
 }
 
 void SortFilterModel::setSortRole(const QString &role)
 {
     m_sortRole = role;
     if (role.isEmpty()) {
         sort(-1, Qt::AscendingOrder);
     } else if (sourceModel()) {
         QSortFilterProxyModel::setSortRole(roleNameToId(role));
         sort(0, sortOrder());
     }
 }
 
 QString SortFilterModel::sortRole() const
 {
     return m_sortRole;
 }
 
 void SortFilterModel::setSortOrder(const Qt::SortOrder order)
 {
     sort(0, order);
 }
 
 QVariantMap SortFilterModel::get(int row) const
 {
     QModelIndex idx = index(row, 0);
     QVariantMap hash;
 
     const QHash<int, QByteArray> rNames = roleNames();
     for (auto i = rNames.begin(); i != rNames.end(); ++i) {
         hash[QString::fromUtf8(i.value())] = data(idx, i.key());
     }
 
     return hash;
 }
 
 int SortFilterModel::mapRowToSource(int row) const
 {
     QModelIndex idx = index(row, 0);
     return mapToSource(idx).row();
 }
 
 int SortFilterModel::mapRowFromSource(int row) const
 {
     if (!sourceModel()) {
         qWarning() << "No source model defined!";
         return -1;
     }
     QModelIndex idx = sourceModel()->index(row, 0);
     return mapFromSource(idx).row();
 }
 
 DataModel::DataModel(QObject *parent)
     : QAbstractItemModel(parent),
       m_dataSource(nullptr),
       m_maxRoleId(Qt::UserRole + 1)
 {
     //There is one reserved role name: DataEngineSource
     m_roleNames[m_maxRoleId] = QByteArrayLiteral("DataEngineSource");
     m_roleIds[QStringLiteral("DataEngineSource")] = m_maxRoleId;
     ++m_maxRoleId;
 
     setObjectName(QStringLiteral("DataModel"));
     connect(this, SIGNAL(rowsInserted(QModelIndex,int,int)),
             this, SIGNAL(countChanged()));
     connect(this, SIGNAL(rowsRemoved(QModelIndex,int,int)),
             this, SIGNAL(countChanged()));
     connect(this, SIGNAL(modelReset()),
             this, SIGNAL(countChanged()));
 }
 
 DataModel::~DataModel()
 {
 }
 
 void DataModel::dataUpdated(const QString &sourceName, const QVariantMap &data)
 {
     if (!m_sourceFilter.isEmpty() && m_sourceFilterRE.isValid() && !m_sourceFilterRE.exactMatch(sourceName)) {
         return;
     }
 
     if (m_keyRoleFilter.isEmpty()) {
         //an item is represented by a source: keys are roles m_roleLevel == FirstLevel
         QVariantList list;
 
         if (!m_dataSource->data()->isEmpty()) {
             foreach (const QString &key, m_dataSource->data()->keys()) {
                 if (!m_sourceFilter.isEmpty() && m_sourceFilterRE.isValid() && !m_sourceFilterRE.exactMatch(key)) {
                     continue;
                 }
                 QVariant value = m_dataSource->data()->value(key);
                 if (value.isValid() && value.canConvert<Plasma::DataEngine::Data>()) {
                     Plasma::DataEngine::Data data = value.value<Plasma::DataEngine::Data>();
                     data[QStringLiteral("DataEngineSource")] = key;
                     list.append(data);
                 }
             }
         }
         setItems(QString(), list);
     } else {
         //a key that matches the one we want exists and is a list of DataEngine::Data
         if (data.contains(m_keyRoleFilter) &&
                 data.value(m_keyRoleFilter).canConvert<QVariantList>()) {
             setItems(sourceName, data.value(m_keyRoleFilter).value<QVariantList>());
         } else if (m_keyRoleFilterRE.isValid()) {
             //try to match the key we want with a regular expression if set
             QVariantList list;
             QVariantMap::const_iterator i;
             for (i = data.constBegin(); i != data.constEnd(); ++i) {
                 if (m_keyRoleFilterRE.exactMatch(i.key())) {
                     list.append(i.value());
                 }
             }
             setItems(sourceName, list);
         }
     }
 }
 
 void DataModel::setDataSource(QObject *object)
 {
     DataSource *source = qobject_cast<DataSource *>(object);
     if (!source) {
         qWarning() << "Error: DataSource type expected";
         return;
     }
     if (m_dataSource == source) {
         return;
     }
 
     if (m_dataSource) {
         disconnect(m_dataSource, nullptr, this, nullptr);
     }
 
     m_dataSource = source;
 
     foreach (const QString &key, m_dataSource->data()->keys()) {
         dataUpdated(key, m_dataSource->data()->value(key).value<Plasma::DataEngine::Data>());
     }
 
     connect(m_dataSource, &DataSource::newData,
             this, &DataModel::dataUpdated);
     connect(m_dataSource, &DataSource::sourceRemoved,
             this, &DataModel::removeSource);
     connect(m_dataSource, &DataSource::sourceDisconnected,
             this, &DataModel::removeSource);
 }
 
 QObject *DataModel::dataSource() const
 {
     return m_dataSource;
 }
 
 void DataModel::setKeyRoleFilter(const QString &key)
 {
     // the "key role filter" can be used in one of three ways:
     //
     // 1) empty string -> all data is used, each source is one row in the model
     // 2) matches a key in the data exactly -> only that key/value pair is used, and the value is
     //    treated as a collection where each item in the collection becomes a row in the model
     // 3) regular expression -> matches zero or more keys in the data, and each matching key/value
     //    pair becomes a row in the model
     if (m_keyRoleFilter == key) {
         return;
     }
 
     m_keyRoleFilter = key;
     m_keyRoleFilterRE = QRegExp(m_keyRoleFilter);
 }
 
 QString DataModel::keyRoleFilter() const
 {
     return m_keyRoleFilter;
 }
 
 void DataModel::setSourceFilter(const QString &key)
 {
     if (m_sourceFilter == key) {
         return;
     }
 
     m_sourceFilter = key;
     m_sourceFilterRE = QRegExp(key);
     /*
      FIXME: if the user changes the source filter, it won't immediately be reflected in the
      available data
     if (m_sourceFilterRE.isValid()) {
         .. iterate through all items and weed out the ones that don't match ..
     }
     */
 }
 
 QString DataModel::sourceFilter() const
 {
     return m_sourceFilter;
 }
 
 void DataModel::setItems(const QString &sourceName, const QVariantList &list)
 {
     const int oldLength = m_items.value(sourceName).count();
     const int delta = list.length() - oldLength;
     const bool firstRun = m_items.isEmpty();
 
     //At what row number the first item associated to this source starts
     int sourceIndex = 0;
     QMap<QString, QVector<QVariant> >::const_iterator i;
     for (i = m_items.constBegin(); i != m_items.constEnd(); ++i) {
         if (i.key() == sourceName) {
             break;
         }
         sourceIndex += i.value().count();
     }
     //signal as inserted the rows at the end, all the other rows will signal a dataupdated.
     //better than a model reset because doesn't cause deletion and re-creation of every list item on a qml ListView, repeaters etc.
     //the first run it gets reset because otherwise setRoleNames gets broken
     if (firstRun) {
         beginResetModel();
     } else if (delta > 0) {
         beginInsertRows(QModelIndex(), sourceIndex + oldLength, sourceIndex + list.length() - 1);
     } else if (delta < 0) {
         beginRemoveRows(QModelIndex(), sourceIndex + list.length(), sourceIndex + oldLength - 1);
     }
     //convert to vector, so data() will be O(1)
     m_items[sourceName] = list.toVector();
 
     if (!list.isEmpty()) {
         if (list.first().canConvert<QVariantMap>()) {
             foreach (const QVariant &item, list) {
                 const QVariantMap &vh = item.value<QVariantMap>();
                 QMapIterator<QString, QVariant> it(vh);
                 while (it.hasNext()) {
                     it.next();
                     const QString &roleName = it.key();
                     if (!m_roleIds.contains(roleName)) {
                         ++m_maxRoleId;
                         m_roleNames[m_maxRoleId] = roleName.toLatin1();
                         m_roleIds[roleName] = m_maxRoleId;
                     }
                 }
             }
         } else {
             foreach (const QVariant &item, list) {
                 const QVariantMap &vh = item.value<QVariantMap>();
                 QMapIterator<QString, QVariant> it(vh);
                 while (it.hasNext()) {
                     it.next();
                     const QString &roleName = it.key();
                     if (!m_roleIds.contains(roleName)) {
                         ++m_maxRoleId;
                         m_roleNames[m_maxRoleId] = roleName.toLatin1();
                         m_roleIds[roleName] = m_maxRoleId;
                     }
                 }
             }
         }
     }
 
     if (firstRun) {
         endResetModel();
     } else if (delta > 0) {
         endInsertRows();
     } else if (delta < 0) {
         endRemoveRows();
     }
     emit dataChanged(createIndex(sourceIndex, 0),
                      createIndex(sourceIndex + qMin(list.length(), oldLength), 0));
 }
 
 QHash<int, QByteArray> DataModel::roleNames() const
 {
     return m_roleNames;
 }
 
 void DataModel::removeSource(const QString &sourceName)
 {
     //FIXME: find a way to remove only the proper things also in the case where sources are items
 
     if (m_keyRoleFilter.isEmpty()) {
         //source name in the map, linear scan
         for (int i = 0; i < m_items.value(QString()).count(); ++i) {
             if (m_items.value(QString())[i].value<QVariantMap>().value(QStringLiteral("DataEngineSource")) == sourceName) {
                 beginRemoveRows(QModelIndex(), i, i);
                 m_items[QString()].remove(i);
                 endRemoveRows();
                 break;
             }
         }
     } else {
         if (m_items.contains(sourceName)) {
             //At what row number the first item associated to this source starts
             int sourceIndex = 0;
             for (auto i = m_items.constBegin(); i != m_items.constEnd(); ++i) {
                 if (i.key() == sourceName) {
                     break;
                 }
                 sourceIndex += i.value().count();
             }
 
             //source name as key of the map
 
             int count = m_items.value(sourceName).count();
             if (count > 0) {
                 beginRemoveRows(QModelIndex(), sourceIndex, sourceIndex + count - 1);
             }
             m_items.remove(sourceName);
             if (count > 0) {
                 endRemoveRows();
             }
         }
     }
 }
 
 QVariant DataModel::data(const QModelIndex &index, int role) const
 {
     if (!index.isValid() || index.column() > 0 ||
             index.row() < 0 || index.row() >= countItems()) {
         return QVariant();
     }
 
     int count = 0;
     int actualRow = 0;
     QString source;
     QMap<QString, QVector<QVariant> >::const_iterator i;
     for (i = m_items.constBegin(); i != m_items.constEnd(); ++i) {
         const int oldCount = count;
         count += i.value().count();
 
         if (index.row() < count) {
             source = i.key();
             actualRow = index.row() - oldCount;
             break;
         }
     }
 
     //is it the reserved role: DataEngineSource ?
     //also, if each source is an item DataEngineSource is a role between all the others, otherwise we know it from the role variable
     if (!m_keyRoleFilter.isEmpty() && m_roleNames.value(role) == "DataEngineSource") {
         return source;
     } else {
         return m_items.value(source).value(actualRow).value<QVariantMap>().value(QString::fromUtf8(m_roleNames.value(role)));
     }
 }
 
 QVariant DataModel::headerData(int section, Qt::Orientation orientation, int role) const
 {
     Q_UNUSED(section)
     Q_UNUSED(orientation)
     Q_UNUSED(role)
 
     return QVariant();
 }
 
 QModelIndex DataModel::index(int row, int column, const QModelIndex &parent) const
 {
     if (parent.isValid() || column > 0 || row < 0 || row >= countItems()) {
         return QModelIndex();
     }
 
     return createIndex(row, column);
 }
 
 QModelIndex DataModel::parent(const QModelIndex &child) const
 {
     Q_UNUSED(child)
 
     return QModelIndex();
 }
 
 int DataModel::rowCount(const QModelIndex &parent) const
 {
     //this is not a tree
     //TODO: make it possible some day?
     if (parent.isValid()) {
         return 0;
     }
 
     return countItems();
 }
 
 int DataModel::columnCount(const QModelIndex &parent) const
 {
     if (parent.isValid()) {
         return 0;
     }
 
     return 1;
 }
 
 QVariantMap DataModel::get(int row) const
 {
     QModelIndex idx = index(row, 0);
     QVariantMap map;
 
     const QHash<int, QByteArray> rNames = roleNames();
     for (auto i = rNames.constBegin(); i != rNames.constEnd(); ++i) {
         map[QString::fromUtf8(i.value())] = data(idx, i.key());
     }
 
     return map;
 }
 
 }