use the function QmlObject::createObjectFromSource

src/scriptengines/qml/declarative/qmlobject.cpp

@@ -50,7 +50,7 @@ public:
         delete root.data();
     }
 
-    void errorPrint();
+    void errorPrint(QQmlComponent *component);
     void execute(const QUrl &source);
     void scheduleExecutionEnd();
     void minimumWidthChanged();
@@ -71,7 +71,7 @@ public:
     bool delay : 1;
 };
 
-void QmlObjectPrivate::errorPrint()
+void QmlObjectPrivate::errorPrint(QQmlComponent *component)
 {
     QString errorStr = "Error loading QML file.\n";
     if(component->isError()){
@@ -181,7 +181,7 @@ void QmlObject::completeInitialization()
         return;
     }
     if (d->component->status() != QQmlComponent::Ready || d->component->isError()) {
-        d->errorPrint();
+        d->errorPrint(d->component);
         return;
     }
 
@@ -195,7 +195,7 @@ void QmlObject::completeInitialization()
     //d->root = d->component->create();
 
     if (!d->root) {
-        d->errorPrint();
+        d->errorPrint(d->component);
     }
 
 #ifndef NDEBUG
@@ -205,6 +205,29 @@ void QmlObject::completeInitialization()
     emit finished();
 }
 
+QObject *QmlObject::createObjectFromSource(const QUrl &source)
+{
+    QQmlComponent *component = new QQmlComponent(d->engine, this);
+    component->loadUrl(source);
+    component->create(d->incubator, d->engine->rootContext());
+    while (!d->incubator.isReady() && d->incubator.status() != QQmlIncubator::Error) {
+        QCoreApplication::processEvents(QEventLoop::AllEvents, 50);
+    }
+    QObject *object = d->incubator.object();
+
+    if (!component->isError() && d->root && object) {
+        //memory management
+        component->setParent(object);
+        object->setProperty("parent", QVariant::fromValue(d->root.data()));
+        return object;
+
+    } else {
+        d->errorPrint(component);
+        delete component;
+        delete object;
+        return 0;
+    }
+}
 
 
 #include "moc_qmlobject.cpp"

src/scriptengines/qml/declarative/qmlobject.h

@@ -158,6 +158,14 @@ public:
      */
     QQmlComponent *mainComponent() const;
 
+    /**
+     * Creates and returns an object based on the provided url to a Qml file
+     * with the same QQmlEngine and the same root context as the amin object,
+     * that will be the parent of the newly created object 
+     * @param source url where the QML file is located
+     */
+    QObject *createObjectFromSource(const QUrl &source);
+
 public Q_SLOTS:
     /**
      * Finishes the process of initialization.

src/scriptengines/qml/plasmoid/appletinterface.cpp

@@ -137,20 +137,15 @@ void AppletInterface::init()
         pkg.setPath("org.kde.toolbox");
 
         if (pkg.isValid()) {
-            QQmlComponent *toolBoxComponent = new QQmlComponent(m_qmlObject->engine(), this);
+            QObject *toolBoxObject = m_qmlObject->createObjectFromSource(QUrl::fromLocalFile(pkg.filePath("mainscript")));
-            toolBoxComponent->loadUrl(QUrl::fromLocalFile(pkg.filePath("mainscript")));
-            QObject *toolBoxObject = toolBoxComponent->create(engine->rootContext());
 
             QObject *containmentGraphicObject = m_qmlObject->rootObject();
 
             if (containmentGraphicObject && toolBoxObject) {
-                //memory management
-                toolBoxComponent->setParent(toolBoxObject);
                 toolBoxObject->setProperty("parent", QVariant::fromValue(containmentGraphicObject));
 
                 containmentGraphicObject->setProperty("toolBox", QVariant::fromValue(toolBoxObject));
             } else {
-                delete toolBoxComponent;
                 delete toolBoxObject;
             }
         } else {
@@ -515,9 +510,7 @@ void AppletInterface::geometryChanged(const QRectF &newGeometry, const QRectF &o
             return;
         }
 
-        QQmlComponent *component = new QQmlComponent(m_qmlObject->engine(), this);
+        m_compactUiObject = m_qmlObject->createObjectFromSource(QUrl::fromLocalFile(applet()->containment()->corona()->package().filePath("ui", "CompactApplet.qml")));
-        component->loadUrl(QUrl::fromLocalFile(applet()->containment()->corona()->package().filePath("ui", "CompactApplet.qml")));
-        m_compactUiObject = component->create(m_qmlObject->engine()->rootContext());
 
         QObject *compactRepresentation = 0;
 
@@ -525,12 +518,13 @@ void AppletInterface::geometryChanged(const QRectF &newGeometry, const QRectF &o
         if (m_compactUiObject) {
             QQmlComponent *compactComponent = m_qmlObject->rootObject()->property("compactRepresentation").value<QQmlComponent *>();
             
-            if (!compactComponent) {
+            if (compactComponent) {
-                compactComponent = new QQmlComponent(m_qmlObject->engine(), this);
-                compactComponent->loadUrl(QUrl::fromLocalFile(applet()->containment()->corona()->package().filePath("ui", "DefaultCompactRepresentation.qml")));
-            }
                 compactRepresentation = compactComponent->create(m_qmlObject->engine()->rootContext());
-            if (compactRepresentation) {
+            } else {
+                compactRepresentation = m_qmlObject->createObjectFromSource(QUrl::fromLocalFile(applet()->containment()->corona()->package().filePath("ui", "DefaultCompactRepresentation.qml")));
+            }
+
+            if (compactRepresentation && compactComponent) {
                 compactComponent->setParent(compactRepresentation);
             } else {
                 delete compactComponent;
@@ -538,9 +532,6 @@ void AppletInterface::geometryChanged(const QRectF &newGeometry, const QRectF &o
         }
 
         if (m_compactUiObject && compactRepresentation) {
-            //for memory management
-            component->setParent(m_compactUiObject.data());
-
             //put compactRepresentation in the icon place
             compactRepresentation->setProperty("parent", QVariant::fromValue(m_compactUiObject.data()));
             m_compactUiObject.data()->setProperty("compactRepresentation", QVariant::fromValue(compactRepresentation));
@@ -558,9 +549,7 @@ void AppletInterface::geometryChanged(const QRectF &newGeometry, const QRectF &o
         
         //failed to create UI, don't do anything, return in expanded status
         } else {
-            qWarning() << component->errors();
             m_expanded = true;
-            delete component;
         }
 
         emit expandedChanged();

src/scriptengines/qml/plasmoid/containmentinterface.cpp

@@ -135,9 +135,7 @@ void ContainmentInterface::appletAddedForward(Plasma::Applet *applet)
 
     //if an appletGraphicObject is not set, we have to display some error message
     } else if (applet && contGraphicObject) {
-        QQmlComponent *component = new QQmlComponent(qmlObject()->engine(), applet);
+        QObject *errorUi = qmlObject()->createObjectFromSource(QUrl::fromLocalFile(containment()->corona()->package().filePath("ui", "AppletError.qml")));
-        component->loadUrl(QUrl::fromLocalFile(containment()->corona()->package().filePath("ui", "AppletError.qml")));
-        QObject *errorUi = component->create();
 
         if (errorUi) {
             errorUi->setProperty("visible", false);