diff --git a/sources/editor/graphicspart/customelementgraphicpart.cpp b/sources/editor/graphicspart/customelementgraphicpart.cpp
index e19280ecc..1ba064e3b 100644
--- a/sources/editor/graphicspart/customelementgraphicpart.cpp
+++ b/sources/editor/graphicspart/customelementgraphicpart.cpp
@@ -144,7 +144,7 @@ void CustomElementGraphicPart::setAntialiased(const bool b)
  * Each style separate by ; and name-style/value are separate by :
  * @param qde : QDOmElement used to write the style.
  */
-void CustomElementGraphicPart::stylesToXml(QDomElement &qde) const
+void CustomElementGraphicPart::stylesToXml(QDomDocument &xml_document, QDomElement &qde) const
 {
 	QString css_like_styles;
 	
@@ -479,9 +479,8 @@ void CustomElementGraphicPart::stylesToXml(QDomElement &qde) const
 	else if (_color == HTMLGrayBlackColor)  css_like_styles += "HTMLGrayBlack";
 	else if (_color == NoneColor)  css_like_styles += "none";
 
-
-	qde.setAttribute("style", css_like_styles);
-	qde.setAttribute("antialias", _antialiased ? "true" : "false");
+    qde.appendChild(createXmlProperty(xml_document, "style", css_like_styles));
+    qde.appendChild(createXmlProperty(xml_document, "antialias", _antialiased ? "true" : "false"));
 }
 
 
@@ -493,13 +492,18 @@ void CustomElementGraphicPart::stylesToXml(QDomElement &qde) const
 void CustomElementGraphicPart::stylesFromXml(const QDomElement &qde)
 {
 	resetStyles();
+
+    QString style_string;
+    propertyString(qde, "style", &style_string);
 	
 		//Get the list of pair style/value
 #if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)	// ### Qt 6: remove
-	QStringList styles = qde.attribute("style").split(";", QString::SkipEmptyParts);
+    QStringList styles = style_string.split(";", QString::SkipEmptyParts);
 #else
-	QStringList styles = qde.attribute("style").split(";", Qt::SkipEmptyParts);
+    QStringList styles = style_string.split(";", Qt::SkipEmptyParts);
 #endif
+
+
 	
 		//Check each pair of style
 	QRegExp rx("^\\s*([a-z-]+)\\s*:\\s*([a-zA-Z-]+)\\s*$");
@@ -843,7 +847,9 @@ void CustomElementGraphicPart::stylesFromXml(const QDomElement &qde)
 		}
 	}
 		//Get antialiasing
-	_antialiased = qde.attribute("antialias") == "true";
+    QString a;
+    propertyString(qde, "antialias", &a);
+    _antialiased = a == "true";
 }
 
 
diff --git a/sources/editor/graphicspart/customelementgraphicpart.h b/sources/editor/graphicspart/customelementgraphicpart.h
index 341c245c2..0fdf5979d 100644
--- a/sources/editor/graphicspart/customelementgraphicpart.h
+++ b/sources/editor/graphicspart/customelementgraphicpart.h
@@ -95,7 +95,7 @@ class CustomElementGraphicPart : public QGraphicsObject, public CustomElementPar
         virtual void resetAllHandlerColor() {}
 
 	protected:
-		void stylesToXml  (QDomElement &) const;
+        void stylesToXml  (QDomDocument &xml_document, QDomElement &) const;
 		void stylesFromXml(const QDomElement &);
 		void resetStyles  ();
 		void applyStylesToQPainter(QPainter &) const;
diff --git a/sources/editor/graphicspart/customelementpart.h b/sources/editor/graphicspart/customelementpart.h
index 3b58a5698..f36658aa0 100644
--- a/sources/editor/graphicspart/customelementpart.h
+++ b/sources/editor/graphicspart/customelementpart.h
@@ -19,6 +19,7 @@
 #define CUSTOM_ELEMENT_PART_H
 
 #include "qet.h"
+#include "propertiesinterface.h"
 
 class CustomElement;
 class ElementPrimitiveDecorator;
@@ -35,7 +36,7 @@ class QGraphicsSceneMouseEvent;
 	is no point for those classes to store their visual representation with
 	anything more complex than a QImage.
 */
-class CustomElementPart {
+class CustomElementPart: public PropertiesInterface {
 	// constructors, destructor
 	public:
 	/**
@@ -55,14 +56,6 @@ class CustomElementPart {
 	
 	// methods
 	public:
-	/**
-		Load the primitive from an XML element that describes it
-	*/
-	virtual void fromXml(const QDomElement &) = 0;
-	/**
-		Export the primitive as an XML element
-	*/
-	virtual const QDomElement toXml(QDomDocument &) const = 0;
 	/**
 		Set a specific property of the primitive
 	*/
diff --git a/sources/editor/graphicspart/partarc.cpp b/sources/editor/graphicspart/partarc.cpp
index a42bff805..c9e526087 100644
--- a/sources/editor/graphicspart/partarc.cpp
+++ b/sources/editor/graphicspart/partarc.cpp
@@ -98,14 +98,18 @@ void PartArc::paint(QPainter *painter, const QStyleOptionGraphicsItem *options,
 const QDomElement PartArc::toXml(QDomDocument &xml_document) const {
 	QDomElement xml_element = xml_document.createElement("arc");
 	QPointF top_left(sceneTopLeft());
-	xml_element.setAttribute("x", QString("%1").arg(top_left.x()));
-	xml_element.setAttribute("y", QString("%1").arg(top_left.y()));
-	xml_element.setAttribute("width",  QString("%1").arg(rect().width()));
-	xml_element.setAttribute("height", QString("%1").arg(rect().height()));
-		//to maintain compatibility with the previous version, we write the angle in degrees.
-	xml_element.setAttribute("start", QString("%1").arg(m_start_angle / 16));
-	xml_element.setAttribute("angle", QString("%1").arg(m_span_angle / 16));
-	stylesToXml(xml_element);
+
+    xml_element.appendChild(createXmlProperty(xml_document, "x", top_left.x()));
+    xml_element.appendChild(createXmlProperty(xml_document, "y", top_left.y()));
+    xml_element.appendChild(createXmlProperty(xml_document, "width", rect().width()));
+    xml_element.appendChild(createXmlProperty(xml_document, "height", rect().height()));
+
+    //to maintain compatibility with the previous version, we write the angle in degrees.
+    xml_element.appendChild(createXmlProperty(xml_document, "start", m_start_angle / 16));
+    xml_element.appendChild(createXmlProperty(xml_document, "angle", m_span_angle / 16));
+
+
+	stylesToXml(xml_document, xml_element);
 	return(xml_element);
 }
 
@@ -115,14 +119,23 @@ const QDomElement PartArc::toXml(QDomDocument &xml_document) const {
  * @param qde : Xml document to use.
  */
 void PartArc::fromXml(const QDomElement &qde) {
-	stylesFromXml(qde);
-	m_rect = QRectF(mapFromScene(qde.attribute("x", "0").toDouble(),
-								 qde.attribute("y", "0").toDouble()),
-					QSizeF(qde.attribute("width",  "0").toDouble(),
-						   qde.attribute("height", "0").toDouble()) );
+    stylesFromXml(qde);
 
-	m_start_angle = qde.attribute("start", "0").toDouble() * 16;
-	m_span_angle  = qde.attribute("angle", "-1440").toDouble() * 16;
+    double x = 0, y = 0, w = 0, h = 0; // default values
+    propertyDouble(qde, "x", &x);
+    propertyDouble(qde, "y", &y);
+    propertyDouble(qde, "width", &w);
+    propertyDouble(qde, "height", &h);
+
+    m_rect = QRectF(mapFromScene(x, y), QSizeF(w, h) );
+
+    m_start_angle = 0;
+    propertyDouble(qde, "start", &m_start_angle);
+    m_start_angle *= 16;
+
+    m_span_angle = -1440;
+    propertyDouble(qde, "angle", &m_span_angle);
+    m_span_angle *= 16;
 }
 
 /**
diff --git a/sources/editor/graphicspart/partellipse.cpp b/sources/editor/graphicspart/partellipse.cpp
index c6fbdcba4..226719010 100644
--- a/sources/editor/graphicspart/partellipse.cpp
+++ b/sources/editor/graphicspart/partellipse.cpp
@@ -82,20 +82,20 @@ const QDomElement PartEllipse::toXml(QDomDocument &xml_document) const
 	if (qFuzzyCompare(rect().width(), rect().height()))
 	{
 		xml_element = xml_document.createElement("circle");
-		xml_element.setAttribute("diameter", QString("%1").arg(rect().width()));
+        xml_element.appendChild(createXmlProperty(xml_document, "diameter", rect().width()));
 	}
 	else
 	{
 		xml_element = xml_document.createElement("ellipse");
-		xml_element.setAttribute("width",  QString("%1").arg(rect().width()));
-		xml_element.setAttribute("height", QString("%1").arg(rect().height()));
+        xml_element.appendChild(createXmlProperty(xml_document, "width", rect().width()));
+        xml_element.appendChild(createXmlProperty(xml_document, "height", rect().height()));
 	}
 
 	QPointF top_left(sceneTopLeft());
-	xml_element.setAttribute("x", QString("%1").arg(top_left.x()));
-	xml_element.setAttribute("y", QString("%1").arg(top_left.y()));
+    xml_element.appendChild(createXmlProperty(xml_document, "x", top_left.x()));
+    xml_element.appendChild(createXmlProperty(xml_document, "y", top_left.y()));
 
-	stylesToXml(xml_element);
+	stylesToXml(xml_document, xml_element);
 
 	return(xml_element);
 }
@@ -108,19 +108,23 @@ const QDomElement PartEllipse::toXml(QDomDocument &xml_document) const
 void PartEllipse::fromXml(const QDomElement &qde)
 {
 	stylesFromXml(qde);
-	qreal width, height;
+    double x = 0, y = 0, width = 0, height = 0;
 
 	if (qde.tagName() == "ellipse")
 	{
-		width = qde.attribute("width",  "0").toDouble();
-		height = qde.attribute("height", "0").toDouble();
+        propertyDouble(qde, "width", &width);
+        propertyDouble(qde, "height", &height);
 	}
-	else
-		width = height = qde.attribute("diameter", "0").toDouble();
+    else {
+        propertyDouble(qde, "diameter", &width);
+        height = width;
+    }
 
-	m_rect = QRectF(mapFromScene(qde.attribute("x", "0").toDouble(),
-								 qde.attribute("y", "0").toDouble()),
-					QSizeF(width, height));
+
+    propertyDouble(qde, "x", &x);
+    propertyDouble(qde, "y", &y);
+
+    m_rect = QRectF(mapFromScene(x, y), QSizeF(width, height));
 }
 
 /**
diff --git a/sources/editor/graphicspart/partline.cpp b/sources/editor/graphicspart/partline.cpp
index fc6d0746e..57d75900d 100644
--- a/sources/editor/graphicspart/partline.cpp
+++ b/sources/editor/graphicspart/partline.cpp
@@ -108,16 +108,18 @@ const QDomElement PartLine::toXml(QDomDocument &xml_document) const
 	QPointF p2(sceneP2());
 	
 	QDomElement xml_element = xml_document.createElement("line");
-	xml_element.setAttribute("x1", QString("%1").arg(p1.x()));
-	xml_element.setAttribute("y1", QString("%1").arg(p1.y()));
-	xml_element.setAttribute("x2", QString("%1").arg(p2.x()));
-	xml_element.setAttribute("y2", QString("%1").arg(p2.y()));
-	xml_element.setAttribute("end1", Qet::endTypeToString(first_end));
-	xml_element.setAttribute("length1", QString("%1").arg(first_length));
-	xml_element.setAttribute("end2", Qet::endTypeToString(second_end));
-	xml_element.setAttribute("length2", QString("%1").arg(second_length));
+
+    xml_element.appendChild(createXmlProperty(xml_document, "x1", p1.x()));
+    xml_element.appendChild(createXmlProperty(xml_document, "y1", p1.y()));
+    xml_element.appendChild(createXmlProperty(xml_document, "x2", p2.x()));
+    xml_element.appendChild(createXmlProperty(xml_document, "y2", p2.y()));
+
+    xml_element.appendChild(createXmlProperty(xml_document, "end1", Qet::endTypeToString(first_end)));
+    xml_element.appendChild(createXmlProperty(xml_document, "length1", first_length));
+    xml_element.appendChild(createXmlProperty(xml_document, "end2", Qet::endTypeToString(second_end)));
+    xml_element.appendChild(createXmlProperty(xml_document, "length2", second_length));
 	
-	stylesToXml(xml_element);
+	stylesToXml(xml_document, xml_element);
 	return(xml_element);
 }
 
@@ -128,15 +130,28 @@ const QDomElement PartLine::toXml(QDomDocument &xml_document) const
  */
 void PartLine::fromXml(const QDomElement &qde) {
 	stylesFromXml(qde);
-	m_line = QLineF(mapFromScene(qde.attribute("x1", "0").toDouble(),
-								 qde.attribute("y1", "0").toDouble()),
-					mapFromScene(qde.attribute("x2", "0").toDouble(),
-								 qde.attribute("y2", "0").toDouble()));
 
-	first_end     = Qet::endTypeFromString(qde.attribute("end1"));
-	first_length  = qde.attribute("length1", "1.5").toDouble();
-	second_end    = Qet::endTypeFromString(qde.attribute("end2"));
-	second_length = qde.attribute("length2", "1.5").toDouble();
+    double x1 = 0, y1 = 0, x2 = 0, y2 = 0;
+    propertyDouble(qde, "x1", &x1);
+    propertyDouble(qde, "y1", &y1);
+    propertyDouble(qde, "x2", &x2);
+    propertyDouble(qde, "y2", &y2);
+
+    m_line = QLineF(mapFromScene(x1, y1),
+                    mapFromScene(x2, y2));
+
+    QString s;
+    propertyString(qde, "end1", &s);
+    first_end = Qet::endTypeFromString(s);
+
+    propertyString(qde, "end2", &s);
+    first_end = Qet::endTypeFromString(s);
+
+    first_length = 1.5;
+    second_length = 1.5;
+
+    propertyDouble(qde, "length1", &first_length);
+    propertyDouble(qde, "length2", &second_length);
 }
 
 /**
diff --git a/sources/editor/graphicspart/partpolygon.cpp b/sources/editor/graphicspart/partpolygon.cpp
index 4767337ca..2e518bf65 100644
--- a/sources/editor/graphicspart/partpolygon.cpp
+++ b/sources/editor/graphicspart/partpolygon.cpp
@@ -89,22 +89,24 @@ void PartPolygon::fromXml(const QDomElement &qde)
 	int i = 1;
 	while(true)
 	{
-		if (QET::attributeIsAReal(qde, QString("x%1").arg(i)) &&\
-			QET::attributeIsAReal(qde, QString("y%1").arg(i)))
-			++ i;
+        if (propertyDouble(qde, QString("x%1").arg(i)) &&
+            propertyDouble(qde, QString("y%1").arg(i)))
+            i++;
 
 		else break;
 	}
 	
 	QPolygonF temp_polygon;
+    double x, y;
 	for (int j = 1 ; j < i ; ++ j)
 	{
-		temp_polygon << QPointF(qde.attribute(QString("x%1").arg(j)).toDouble(),
-								qde.attribute(QString("y%1").arg(j)).toDouble());
+        propertyDouble(qde, QString("x%1").arg(j), &x);
+        propertyDouble(qde, QString("y%1").arg(j), &y);
+        temp_polygon << QPointF(x, y);
 	}
 	m_polygon = temp_polygon;
 	
-	m_closed = qde.attribute("closed") != "false";
+    propertyBool(qde, "closed", &m_closed);
 }
 
 /**
@@ -119,12 +121,14 @@ const QDomElement PartPolygon::toXml(QDomDocument &xml_document) const
 	int i = 1;
 	foreach(QPointF point, m_polygon) {
 		point = mapToScene(point);
-		xml_element.setAttribute(QString("x%1").arg(i), QString("%1").arg(point.x()));
-		xml_element.setAttribute(QString("y%1").arg(i), QString("%1").arg(point.y()));
+        xml_element.appendChild(createXmlProperty(xml_document, QString("x%1").arg(i), point.x()));
+        xml_element.appendChild(createXmlProperty(xml_document, QString("y%1").arg(i), point.y()));
 		++ i;
 	}
-	if (!m_closed) xml_element.setAttribute("closed", "false");
-	stylesToXml(xml_element);
+
+    xml_element.appendChild(createXmlProperty(xml_document, "closed", m_closed));
+
+    stylesToXml(xml_document, xml_element);
 	return(xml_element);
 }
 
diff --git a/sources/editor/graphicspart/partrectangle.cpp b/sources/editor/graphicspart/partrectangle.cpp
index 5f17b7252..96ad18a1f 100644
--- a/sources/editor/graphicspart/partrectangle.cpp
+++ b/sources/editor/graphicspart/partrectangle.cpp
@@ -81,10 +81,11 @@ const QDomElement PartRectangle::toXml(QDomDocument &xml_document) const
 {
 	QDomElement xml_element = xml_document.createElement("rect");
 	QPointF top_left(sceneTopLeft());
-	xml_element.setAttribute("x", QString("%1").arg(top_left.x()));
-	xml_element.setAttribute("y", QString("%1").arg(top_left.y()));
-	xml_element.setAttribute("width",  QString("%1").arg(m_rect.width()));
-	xml_element.setAttribute("height", QString("%1").arg(m_rect.height()));
+
+    xml_element.appendChild(createXmlProperty(xml_document, "x", top_left.x()));
+    xml_element.appendChild(createXmlProperty(xml_document, "y", top_left.y()));
+    xml_element.appendChild(createXmlProperty(xml_document, "width", m_rect.width()));
+    xml_element.appendChild(createXmlProperty(xml_document, "height", m_rect.height()));
 	
 	QRectF rect = m_rect.normalized();
 	qreal x = m_xRadius;
@@ -98,8 +99,11 @@ const QDomElement PartRectangle::toXml(QDomDocument &xml_document) const
 	
 	xml_element.setAttribute("rx", QString::number(m_xRadius));
 	xml_element.setAttribute("ry", QString::number(m_yRadius));
+
+    xml_element.appendChild(createXmlProperty(xml_document, "rx", m_xRadius));
+    xml_element.appendChild(createXmlProperty(xml_document, "ry", m_yRadius));
 	
-	stylesToXml(xml_element);
+    stylesToXml(xml_document, xml_element);
 	return(xml_element);
 }
 
diff --git a/sources/editor/graphicspart/parttext.cpp b/sources/editor/graphicspart/parttext.cpp
index 9e1b9b5c6..e3dbf794a 100644
--- a/sources/editor/graphicspart/parttext.cpp
+++ b/sources/editor/graphicspart/parttext.cpp
@@ -59,28 +59,41 @@ void PartText::fromXml(const QDomElement &xml_element)
 {
 	bool ok;
 
-	if (xml_element.hasAttribute("size"))
+    int size;
+    QString font;
+
+    if (propertyInteger(xml_element, "size", &size) != PropertyFlags::NotFound)
 	{
-		int font_size = xml_element.attribute("size").toInt(&ok);
-		if (!ok || font_size < 1) {
-			font_size = 20;
+        if (size < 1) {
+            size = 20;
 		}
 		QFont font_ = this->font();
-		font_.setPointSize(font_size);
+        font_.setPointSize(size);
 		setFont(font_);
 	}
-	else if (xml_element.hasAttribute("font"))
+    else if (propertyString(xml_element, "font", &font) != PropertyFlags::NotFound)
 	{
 		QFont font_;
-		font_.fromString(xml_element.attribute("font"));
+        font_.fromString(font);
 		setFont(font_);
-	}
+    }
 	
-	setDefaultTextColor(QColor(xml_element.attribute("color", "#000000")));
-	setPlainText(xml_element.attribute("text"));
-	setPos(xml_element.attribute("x").toDouble(),
-		   xml_element.attribute("y").toDouble());
-	setRotation(xml_element.attribute("rotation", QString::number(0)).toDouble());
+    QString color;
+    QString text;
+    propertyString(xml_element, "color", &color, "#000000");
+    setDefaultTextColor(QColor(color));
+
+
+    propertyString(xml_element, "text", &text);
+    setPlainText(text);
+
+    double x, y, rot;
+    propertyDouble(xml_element, "x", &x, 0);
+    propertyDouble(xml_element, "y", &y, 0);
+    setPos(x, y);
+
+    propertyDouble(xml_element, "rotation", &rot, 0);
+    setRotation(rot);
 }
 
 /**
@@ -92,12 +105,12 @@ const QDomElement PartText::toXml(QDomDocument &xml_document) const
 {
 	QDomElement xml_element = xml_document.createElement(xmlName());
 
-	xml_element.setAttribute("x", QString::number(pos().x()));
-	xml_element.setAttribute("y", QString::number(pos().y()));
-	xml_element.setAttribute("text", toPlainText());
-	xml_element.setAttribute("font", font().toString());
-	xml_element.setAttribute("rotation", QString::number(rotation()));
-	xml_element.setAttribute("color", defaultTextColor().name());
+    xml_element.appendChild(createXmlProperty(xml_document, "x", pos().x()));
+    xml_element.appendChild(createXmlProperty(xml_document, "y", pos().y()));
+    xml_element.appendChild(createXmlProperty(xml_document, "text", toPlainText()));
+    xml_element.appendChild(createXmlProperty(xml_document, "font", font().toString()));
+    xml_element.appendChild(createXmlProperty(xml_document, "rotation", rotation()));
+    xml_element.appendChild(createXmlProperty(xml_document, "color", defaultTextColor().name()));
 
 	return(xml_element);
 }
diff --git a/sources/properties/propertiesinterface.cpp b/sources/properties/propertiesinterface.cpp
index da7b042d4..9ffd197a5 100644
--- a/sources/properties/propertiesinterface.cpp
+++ b/sources/properties/propertiesinterface.cpp
@@ -17,6 +17,224 @@
 */
 #include "propertiesinterface.h"
 
+/*!
+ * Available property types
+ */
+namespace  {
+    const QString integerS = "int";
+    const QString doubleS = "double";
+    const QString boolS = "bool";
+    const QString stringS = "string";
+}
+
 PropertiesInterface::PropertiesInterface()
 {
 }
+
+QDomElement PropertiesInterface::createXmlProperty(QDomDocument &doc, const QString& name, const QString value) const {
+    QDomElement p = doc.createElement("property");
+    p.setAttribute("name", name);
+    p.setAttribute("type", stringS);
+    p.setAttribute("value", value);
+    return p;
+}
+
+QDomElement PropertiesInterface::createXmlProperty(QDomDocument& doc, const QString& name, const int value) const {
+    QDomElement p = doc.createElement("property");
+    p.setAttribute("name", name);
+    p.setAttribute("type", integerS);
+    p.setAttribute("value", value);
+    return p;
+}
+
+QDomElement PropertiesInterface::createXmlProperty(QDomDocument& doc, const QString& name, const double value) const {
+    QDomElement p = doc.createElement("property");
+    p.setAttribute("name", name);
+    p.setAttribute("type", doubleS);
+    p.setAttribute("value", value);
+    return p;
+}
+
+QDomElement PropertiesInterface::createXmlProperty(QDomDocument& doc, const QString& name, const bool value) const {
+    QDomElement p = doc.createElement("property");
+    p.setAttribute("name", name);
+    p.setAttribute("type", boolS);
+    p.setAttribute("value", value);
+    return p;
+}
+
+QDomElement PropertiesInterface::property(const QDomElement& e, const QString& name) {
+    for (int i=0; i < e.childNodes().count(); i++) {
+        QDomElement child = e.childNodes().at(i).toElement();
+        if (!validXmlProperty(child))
+            return QDomElement();
+
+        if (child.attribute("name") == name)
+            return child;
+    }
+    return QDomElement();
+}
+
+/*!
+ * \brief PropertiesInterface::attribute
+ * Returns the property with the name \p attribute_name
+ * \param e Xml element which contains the property
+ * \param attribute_name
+ * \param type Type of the property
+ * \param attr
+ * \return
+ */
+bool PropertiesInterface::attribute(const QDomElement& e, const QString& attribute_name, const QString& type, QString* attr) {
+    QDomElement p = property(e, attribute_name);
+    if (p.isNull()) {
+        // check if legacy property is available,
+        // where the property is inside the element as attribute
+        if (!e.hasAttribute(attribute_name))
+            return false;
+
+        *attr = e.attribute(attribute_name);
+
+    } else {
+        if (p.attribute("type") != type)
+            return false;
+
+        *attr = p.attribute("value");
+
+    }
+    return true;
+}
+
+/*!
+ * \brief PropertiesInterface::propertyInteger
+ * Reads an interger from the XML element.
+ * \param e DomElement which contains the property attribute
+ * \param attribute_name Name of the attribute
+ * \param entier Return value if success
+ * \return True if reading an integer was successful, else False. If the attribute was not found,
+ *          \p entier is not valid and the return value is False
+ */
+PropertiesInterface::PropertyFlags PropertiesInterface::propertyInteger(const QDomElement &e, const QString& attribute_name, int* entier, int defaultValue) {
+
+    QString attr;
+
+    if (!attribute(e, attribute_name, integerS, &attr)) {
+        *entier = defaultValue;
+        return PropertyFlags::NotFound;
+    }
+
+    // verifie la validite de l'attribut
+    bool ok;
+    int tmp = attr.toInt(&ok);
+    if (!ok)
+        return PropertyFlags::NoValidConversion;
+
+    if (entier != nullptr)
+        *entier = tmp;
+
+    return PropertyFlags::Success;
+}
+
+PropertiesInterface::PropertyFlags PropertiesInterface::propertyDouble(const QDomElement &e, const QString& attribute_name, double* reel, double defaultValue) {
+
+    QString attr;
+
+    if (!attribute(e, attribute_name, doubleS, &attr)) {
+        *reel = defaultValue;
+        return PropertyFlags::NotFound;
+    }
+
+    // verifie la validite de l'attribut
+    bool ok;
+    double tmp = attr.toDouble(&ok);
+    if (!ok)
+        return PropertyFlags::NoValidConversion;
+
+    if (reel != nullptr)
+        *reel = tmp;
+
+    return PropertyFlags::Success;
+}
+
+PropertiesInterface::PropertyFlags PropertiesInterface::propertyBool(const QDomElement &e, const QString& attribute_name, bool* boolean, bool defaulValue) {
+
+    QString attr;
+
+    if (!attribute(e, attribute_name, integerS, &attr)) {
+        *boolean = defaulValue;
+        return PropertyFlags::NotFound;
+    }
+
+    // verifie la validite de l'attribut
+    bool ok;
+    bool tmp = attr.toInt(&ok);
+    if (!ok)
+        return PropertyFlags::NoValidConversion;
+
+    if (boolean != nullptr)
+        *boolean = tmp;
+
+    return PropertyFlags::Success;
+}
+
+PropertiesInterface::PropertyFlags PropertiesInterface::propertyString(const QDomElement& e, const QString& attribute_name, QString* string, QString defaultValue) {
+
+    QString attr;
+    if (!attribute(e, attribute_name, stringS, &attr)) {
+        *string = defaultValue;
+        return PropertyFlags::NotFound;
+    }
+
+    // verifie la validite de l'attribut
+    if (string != nullptr)
+        *string = attr;
+
+    return PropertyFlags::Success;
+}
+
+/*!
+ * \brief PropertiesInterface::validXmlProperty
+ * Check if the Xml element contains the needed fields
+ * \param e Xml Property
+ * \return True if name, type, value attribute are available, else false
+ */
+bool PropertiesInterface::validXmlProperty(const QDomElement& e) {
+    if (!e.hasAttribute("name"))
+        return false;
+
+    if (!e.hasAttribute("type"))
+        return false;
+
+    if (!e.hasAttribute("value"))
+        return false;
+}
+
+/**
+    Permet de convertir une chaine de caracteres ("n", "s", "e" ou "w")
+    en orientation. Si la chaine fait plusieurs caracteres, seul le
+    premier est pris en compte. En cas d'incoherence, Qet::North est
+    retourne.
+    @param s Chaine de caractere cense representer une orientation
+    @return l'orientation designee par la chaine de caractere
+*/
+Qet::Orientation PropertiesInterface::orientationFromString(const QString &s) {
+    QChar c = s[0];
+    if (c == 'e') return(Qet::East);
+    else if (c == 's') return(Qet::South);
+    else if (c == 'w') return (Qet::West);
+    else return(Qet::North);
+}
+
+/**
+    @param o une orientation
+    @return une chaine de caractere representant l'orientation
+*/
+QString PropertiesInterface::orientationToString(Qet::Orientation o) {
+    QString ret;
+    switch(o) {
+        case Qet::North: ret = "n"; break;
+        case Qet::East : ret = "e"; break;
+        case Qet::South: ret = "s"; break;
+        case Qet::West : ret = "w"; break;
+    }
+    return(ret);
+}
diff --git a/sources/properties/propertiesinterface.h b/sources/properties/propertiesinterface.h
index 0799ab69b..0c4bc5793 100644
--- a/sources/properties/propertiesinterface.h
+++ b/sources/properties/propertiesinterface.h
@@ -21,6 +21,8 @@
 #include <QString>
 #include <QSettings>
 #include <QDomElement>
+#include <limits>
+#include "qet.h"
 
 /**
  * @brief The PropertiesInterface class
@@ -36,6 +38,49 @@ class PropertiesInterface
 	// Save/load properties to xml element
     virtual QDomElement toXml		  (QDomDocument &xml_document) const =0;
     virtual bool fromXml	  (const QDomElement &xml_element) =0;
+    virtual bool valideXml(QDomElement& element) const = 0;
+
+    /*!
+     * Use this functions to add properties to the xml document
+     */
+    QDomElement createXmlProperty(QDomDocument& doc, const QString& name, const QString value) const;
+    QDomElement createXmlProperty(QDomDocument& doc, const QString& name, const int value) const;
+    QDomElement createXmlProperty(QDomDocument& doc, const QString& name, const double value) const;
+    QDomElement createXmlProperty(QDomDocument& doc, const QString& name, const bool value) const;
+
+    static QDomElement property(const QDomElement& e, const QString& name);
+    static bool attribute(const QDomElement& e, const QString& attribute_name, const QString& type, QString* attr);
+
+    typedef enum PropertyFlags {
+        Success,
+        NotFound,
+        NoValidConversion,
+    };
+
+    static PropertyFlags propertyInteger(const QDomElement &e, const QString& attribute_name, int *entier = nullptr, int defaultValue = std::numeric_limits<int>::quiet_NaN());
+    static PropertyFlags propertyDouble(const QDomElement &e, const QString& attribute_name, double *reel = nullptr, double defaultValue = std::numeric_limits<double>::quiet_NaN());
+    static PropertyFlags propertyString(const QDomElement& e, const QString& attribute_name, QString* string = nullptr, QString defaultValue = QString());
+    static PropertyFlags propertyBool(const QDomElement &e, const QString& attribute_name, bool* boolean = nullptr, bool defaulValue = false);
+
+    static bool validXmlProperty(const QDomElement& e);
+
+    QVariant XmlProperty(const QDomElement& element);
+
+    /**
+        Permet de convertir une chaine de caracteres ("n", "s", "e" ou "w")
+        en orientation. Si la chaine fait plusieurs caracteres, seul le
+        premier est pris en compte. En cas d'incoherence, Qet::North est
+        retourne.
+        @param s Chaine de caractere cense representer une orientation
+        @return l'orientation designee par la chaine de caractere
+    */
+    static Qet::Orientation orientationFromString(const QString &s);
+
+    /**
+        @param o une orientation
+        @return une chaine de caractere representant l'orientation
+    */
+    static QString orientationToString(Qet::Orientation o);
 };
 
 #endif // PROPERTIESINTERFACE_H
diff --git a/sources/properties/terminaldata.cpp b/sources/properties/terminaldata.cpp
index 27bf607f2..2aefb0710 100644
--- a/sources/properties/terminaldata.cpp
+++ b/sources/properties/terminaldata.cpp
@@ -43,17 +43,11 @@ QDomElement TerminalData::toXml(QDomDocument &xml_document) const
 {
     QDomElement xml_element = xml_document.createElement("terminal");
 
-    // ecrit la position de la borne
-    xml_element.setAttribute("x", QString("%1").arg(q->scenePos().x()));
-    xml_element.setAttribute("y", QString("%1").arg(q->scenePos().y()));
-
-
-    xml_element.setAttribute("uuid", m_uuid.toString());
-    xml_element.setAttribute("name", m_name);
-
-    // ecrit l'orientation de la borne
-    xml_element.setAttribute("orientation", Qet::orientationToString(m_orientation));
-    // Write name and number to XML
+    xml_element.appendChild(createXmlProperty(xml_document, "x", q->scenePos().x()));
+    xml_element.appendChild(createXmlProperty(xml_document, "y", q->scenePos().y()));
+    xml_element.appendChild(createXmlProperty(xml_document, "uuid", m_uuid.toString()));
+    xml_element.appendChild(createXmlProperty(xml_document, "name", m_name));
+    xml_element.appendChild(createXmlProperty(xml_document, "orientation", orientationToString(m_orientation)));
 
     return(xml_element);
 }
@@ -61,27 +55,40 @@ bool TerminalData::fromXml (const QDomElement &xml_element)
 {
     // lit la position de la borne
     qreal term_x = 0.0, term_y = 0.0;
-    if (!QET::attributeIsAReal(xml_element, "x", &term_x))
+
+    if (!propertyDouble(xml_element, "x", &term_x))
         return false;
 
-    if (!QET::attributeIsAReal(xml_element, "y", &term_y))
+    if (!propertyDouble(xml_element, "y", &term_y))
         return false;
 
     m_pos = QPointF(term_x, term_y);
 
     //emit posFromXML(QPointF(term_x, term_y));
 
-    QString uuid = xml_element.attribute("uuid");
+    QString uuid;
+    if (!propertyString(xml_element, "uuid", &uuid))
+        return false;
+
     // update part and add uuid, which is used in the new version to connect terminals together
     // if the attribute not exists, means, the element is created with an older version of qet. So use the legacy approach
     // to identify terminals
     if (!uuid.isEmpty())
         m_uuid = QUuid(uuid);
 
-    m_name = xml_element.attribute("name");
+    if (!propertyString(xml_element, "name", &m_name))
+        return false;
+
+    QString o;
+    if (!propertyString(xml_element, "orientation", &o))
+        return false;
 
     // lit l'orientation de la borne
-    m_orientation = Qet::orientationFromString(xml_element.attribute("orientation"));
+    m_orientation = orientationFromString(o);
 
     return true;
 }
+
+bool TerminalData::valideXml(QDomElement& element) const {
+    return true;
+}
diff --git a/sources/properties/terminaldata.h b/sources/properties/terminaldata.h
index c31e73929..4d5301cda 100644
--- a/sources/properties/terminaldata.h
+++ b/sources/properties/terminaldata.h
@@ -35,6 +35,24 @@ public:
     QDomElement toXml(QDomDocument &xml_element) const override;
     bool fromXml(const QDomElement &xml_element) override;
 
+    bool valideXml(QDomElement  &element) const override;
+
+    /**
+        Permet de convertir une chaine de caracteres ("n", "s", "e" ou "w")
+        en orientation. Si la chaine fait plusieurs caracteres, seul le
+        premier est pris en compte. En cas d'incoherence, Qet::North est
+        retourne.
+        @param s Chaine de caractere cense representer une orientation
+        @return l'orientation designee par la chaine de caractere
+    */
+    static Qet::Orientation orientationFromString(const QString &s);
+
+    /**
+        @param o une orientation
+        @return une chaine de caractere representant l'orientation
+    */
+    static QString orientationToString(Qet::Orientation o);
+
     // must be public, because this class is a private member of PartTerminal/Terminal and they must
     // access this data
 public:
diff --git a/sources/properties/xrefproperties.cpp b/sources/properties/xrefproperties.cpp
index 538549761..360ad9b5f 100644
--- a/sources/properties/xrefproperties.cpp
+++ b/sources/properties/xrefproperties.cpp
@@ -96,27 +96,21 @@ void XRefProperties::fromSettings(const QSettings &settings, const QString prefi
 QDomElement XRefProperties::toXml(QDomDocument &xml_document) const {
 
     QDomElement xml_element = xml_document.createElement("xref");
-    xml_element.setAttribute("type", m_key);
 
-    xml_element.setAttribute("showpowerctc", m_show_power_ctc? "true" : "false");
-	QString display = m_display == Cross? "cross" : "contacts";
-	xml_element.setAttribute("displayhas", display);
-	QString snap = m_snap_to == Bottom? "bottom" : "label";
-	xml_element.setAttribute("snapto", snap);
+    xml_element.appendChild(createXmlProperty(xml_document, "type", m_key));
+    xml_element.appendChild(createXmlProperty(xml_document, "showpowerctc", m_show_power_ctc));
+    xml_element.appendChild(createXmlProperty(xml_document, "displayhas", m_display == Cross? "cross" : "contacts"));
+    xml_element.appendChild(createXmlProperty(xml_document, "snapto", m_snap_to == Bottom? "bottom" : "label"));
 
-	QString xrefpos;
-	
-	QMetaEnum var = QMetaEnum::fromType<Qt::Alignment>();
-	xml_element.setAttribute("xrefpos",  var.valueToKey(m_xref_pos));
 
-	int offset = m_offset;
-	xml_element.setAttribute("offset", QString::number(offset));
-	QString master_label = m_master_label;
-	xml_element.setAttribute("master_label", master_label);
-	QString slave_label = m_slave_label;
-	xml_element.setAttribute("slave_label", slave_label);
+    QMetaEnum var = QMetaEnum::fromType<Qt::Alignment>();
+    xml_element.appendChild(createXmlProperty(xml_document, "xrefpos", var.valueToKey(m_xref_pos)));
+    xml_element.appendChild(createXmlProperty(xml_document, "offset", m_offset));
+    xml_element.appendChild(createXmlProperty(xml_document, "master_label", m_master_label));
+    xml_element.appendChild(createXmlProperty(xml_document, "slave_label", m_slave_label));
+
 	foreach (QString key, m_prefix.keys()) {
-		xml_element.setAttribute(key + "prefix", m_prefix.value(key));
+        xml_element.appendChild(createXmlProperty(xml_document, key + "prefix", m_prefix.value(key)));
 	}
 
     return xml_element;
@@ -128,30 +122,42 @@ QDomElement XRefProperties::toXml(QDomDocument &xml_document) const {
  * @param xml_element: QDomElement to use for load
  */
 bool XRefProperties::fromXml(const QDomElement &xml_element) {
-	m_show_power_ctc = xml_element.attribute("showpowerctc")  == "true";
-	QString display = xml_element.attribute("displayhas", "cross");
+
+    if (!propertyBool(xml_element, "showpowerctc", &m_show_power_ctc))
+        return false;
+
+    QString display;
+    propertyString(xml_element, "displayhas", &display, "cross");
 	display == "cross"? m_display = Cross : m_display = Contacts;
-	QString snap = xml_element.attribute("snapto", "label");
+
+
+    QString snap;
+    propertyString(xml_element, "snapto", &snap, "label");
 	snap == "bottom"? m_snap_to = Bottom : m_snap_to = Label;
 
-	QString xrefpos = xml_element.attribute("xrefpos","Left");
+    QString xrefpos;
+    if (propertyString(xml_element, "xrefpos", &xrefpos, "Left") == PropertyFlags::NotFound) {
+        QMetaEnum var = QMetaEnum::fromType<Qt::Alignment>();
+        m_xref_pos = Qt::AlignmentFlag(var.keyToValue(xrefpos.toStdString().data()));
+    } else
+        m_xref_pos = Qt::AlignBottom;
 
-	QMetaEnum var = QMetaEnum::fromType<Qt::Alignment>();
-
-	if(xml_element.hasAttribute("xrefpos"))
-		m_xref_pos = Qt::AlignmentFlag(var.keyToValue(xml_element.attribute("xrefpos").toStdString().data()));
-	else
-		m_xref_pos = Qt::AlignBottom;
-
-	m_offset = xml_element.attribute("offset", "0").toInt();
-	m_master_label = xml_element.attribute("master_label", "%f-%l%c");
-	m_slave_label = xml_element.attribute("slave_label","(%f-%l%c)");
+    propertyInteger(xml_element, "offset", &m_offset, 0);
+    propertyString(xml_element, "master_label", &m_master_label, "%f-%l%c");
+    propertyString(xml_element, "slave_label", &m_slave_label, "(%f-%l%c)");
+    QString value;
 	foreach (QString key, m_prefix_keys) {
-		m_prefix.insert(key, xml_element.attribute(key + "prefix"));
+        propertyString(xml_element, key + "prefix", &value);
+        m_prefix.insert(key, value);
 	}
     return true;
 }
 
+bool XRefProperties::valideXml(QDomElement& element) const {
+    // TODO: implement
+    return true;
+}
+
 /**
  * @brief XRefProperties::defaultProperties
  * @return the default properties stored in the setting file
diff --git a/sources/properties/xrefproperties.h b/sources/properties/xrefproperties.h
index dc03196cf..e10ee872a 100644
--- a/sources/properties/xrefproperties.h
+++ b/sources/properties/xrefproperties.h
@@ -44,6 +44,7 @@ class XRefProperties : public PropertiesInterface
 	void fromSettings (const QSettings &settings, const QString = QString()) override;
     QDomElement toXml		  (QDomDocument &xml_document) const override;
     bool fromXml(const QDomElement &xml_element) override;
+    bool valideXml(QDomElement& element) const override;
 
 	static QHash<QString, XRefProperties> defaultProperties();
 
diff --git a/sources/qet.cpp b/sources/qet.cpp
index 928ccda86..c2702e7bf 100644
--- a/sources/qet.cpp
+++ b/sources/qet.cpp
@@ -25,37 +25,6 @@
 #include <QSaveFile>
 #include <QTextStream>
 
-/**
-	Permet de convertir une chaine de caracteres ("n", "s", "e" ou "w")
-	en orientation. Si la chaine fait plusieurs caracteres, seul le
-	premier est pris en compte. En cas d'incoherence, Qet::North est
-	retourne.
-	@param s Chaine de caractere cense representer une orientation
-	@return l'orientation designee par la chaine de caractere
-*/
-Qet::Orientation Qet::orientationFromString(const QString &s) {
-	QChar c = s[0];
-	if (c == 'e') return(Qet::East);
-	else if (c == 's') return(Qet::South);
-	else if (c == 'w') return (Qet::West);
-	else return(Qet::North);
-}
-
-/**
-	@param o une orientation
-	@return une chaine de caractere representant l'orientation
-*/
-QString Qet::orientationToString(Qet::Orientation o) {
-	QString ret;
-	switch(o) {
-		case Qet::North: ret = "n"; break;
-		case Qet::East : ret = "e"; break;
-		case Qet::South: ret = "s"; break;
-		case Qet::West : ret = "w"; break;
-	}
-	return(ret);
-}
-
 /**
 	Indique si deux orientations de Borne sont sur le meme axe (Vertical / Horizontal).
 	@param a La premiere orientation de Borne
diff --git a/sources/qetgraphicsitem/terminal.cpp b/sources/qetgraphicsitem/terminal.cpp
index 1f32441b6..f2f13dfe6 100644
--- a/sources/qetgraphicsitem/terminal.cpp
+++ b/sources/qetgraphicsitem/terminal.cpp
@@ -719,15 +719,13 @@ QList<Conductor *> Terminal::conductors() const {
 QDomElement Terminal::toXml(QDomDocument &doc) const {
 	QDomElement qdo = doc.createElement("terminal");
 
-	// for backward compatibility
-	qdo.setAttribute("x", QString("%1").arg(dock_elmt_.x()));
-	qdo.setAttribute("y",  QString("%1").arg(dock_elmt_.y()));
-	// end for backward compatibility
+    qdo.appendChild(createXmlProperty(doc, "x", dock_elmt_.x()));
+    qdo.appendChild(createXmlProperty(doc, "y", dock_elmt_.y()));
+    qdo.appendChild(createXmlProperty(doc, "orientation", orientationToString(d->m_orientation)));
+    qdo.appendChild(createXmlProperty(doc, "number", number_terminal_));
+    qdo.appendChild(createXmlProperty(doc, "name", name_terminal_));
+    qdo.appendChild(createXmlProperty(doc, "nameHidden", name_terminal_hidden));
 
-	qdo.setAttribute("orientation", d->m_orientation);
-	qdo.setAttribute("number", number_terminal_);
-	qdo.setAttribute("name", name_terminal_);
-	qdo.setAttribute("nameHidden", name_terminal_hidden);
 	return(qdo);
 }
 
@@ -737,38 +735,36 @@ QDomElement Terminal::toXml(QDomDocument &doc) const {
 	@param terminal Le QDomElement a analyser
 	@return true si le QDomElement passe en parametre est une borne, false sinon
 */
-bool Terminal::valideXml(QDomElement &terminal) {
-	// verifie le nom du tag
+bool Terminal::valideXml(QDomElement &terminal) const {
 	if (terminal.tagName() != "terminal") return(false);
+
+    if (!propertyString(terminal, "number", nullptr))
+        return false;
+
+    if (!propertyString(terminal, "name", nullptr))
+        return false;
+
+    if (!propertyBool(terminal, "nameHidden", nullptr))
+        return false;
+
+    if (!propertyDouble(terminal, "x", nullptr))
+        return false;
+    if (!propertyDouble(terminal, "y", nullptr))
+        return false;
+
+    QString o;
+    if (!propertyString(terminal, "orientation", &o))
+        return false;
+
+    Qet::Orientation terminal_or = orientationFromString(o);
+    if (terminal_or != Qet::North
+            && terminal_or != Qet::South
+            && terminal_or != Qet::East
+            && terminal_or != Qet::West)
+        return false;
 	
-	// verifie la presence des attributs minimaux
-	if (!terminal.hasAttribute("x")) return(false);
-	if (!terminal.hasAttribute("y")) return(false);
-	if (!terminal.hasAttribute("orientation")) return(false);
-	
-	bool conv_ok;
-	// parse l'abscisse
-	terminal.attribute("x").toDouble(&conv_ok);
-	if (!conv_ok) return(false);
-	
-	// parse l'ordonnee
-	terminal.attribute("y").toDouble(&conv_ok);
-	if (!conv_ok) return(false);
-	
-	// parse l'id
-	terminal.attribute("id").toInt(&conv_ok);
-	if (!conv_ok) return(false);
-	
-	// parse l'orientation
-	int terminal_or = terminal.attribute("orientation").toInt(&conv_ok);
-	if (!conv_ok) return(false);
-	if (terminal_or != Qet::North
-			&& terminal_or != Qet::South
-			&& terminal_or != Qet::East
-			&& terminal_or != Qet::West) return(false);
-	
-	// a ce stade, la borne est syntaxiquement correcte
-	return(true);
+    // a ce stade, la borne est syntaxiquement correcte
+    return true;
 }
 
 /**
@@ -779,15 +775,30 @@ bool Terminal::valideXml(QDomElement &terminal) {
 	@return true si la borne "se reconnait"
 	(memes coordonnes, meme orientation), false sinon
 */
-bool Terminal::fromXml(QDomElement &terminal) {
-	number_terminal_ = terminal.attribute("number");
-	name_terminal_ = terminal.attribute("name");
-	name_terminal_hidden = terminal.attribute("nameHidden").toInt();
+bool Terminal::fromXml(const QDomElement &terminal) {
+    if (!propertyString(terminal, "number", &number_terminal_))
+        return false;
 
-	return (
-		qFuzzyCompare(terminal.attribute("x").toDouble(), dock_elmt_.x()) &&
-		qFuzzyCompare(terminal.attribute("y").toDouble(), dock_elmt_.y()) &&
-		(terminal.attribute("orientation").toInt() == d->m_orientation)
+    if (!propertyString(terminal, "name", &name_terminal_))
+        return false;
+
+    if (!propertyBool(terminal, "nameHidden", &name_terminal_hidden))
+        return false;
+
+    double x, y;
+    if (!propertyDouble(terminal, "x", &x))
+        return false;
+    if (!propertyDouble(terminal, "y", &y))
+        return false;
+
+    QString o;
+    if (!propertyString(terminal, "orientation", &o))
+        return false;
+
+    return (
+        qFuzzyCompare(x, dock_elmt_.x()) &&
+        qFuzzyCompare(y, dock_elmt_.y()) &&
+        (orientationFromString(o) == d->m_orientation)
 	);
 }
 
diff --git a/sources/qetgraphicsitem/terminal.h b/sources/qetgraphicsitem/terminal.h
index 17e9d7833..b33fdcae9 100644
--- a/sources/qetgraphicsitem/terminal.h
+++ b/sources/qetgraphicsitem/terminal.h
@@ -20,6 +20,8 @@
 #include <QtWidgets>
 #include <QtXml>
 #include "qet.h"
+#include "propertiesinterface.h"
+
 class Conductor;
 class Diagram;
 class Element;
@@ -31,7 +33,7 @@ class TerminalData;
 	plug point for conductors.
 	This class handles all mouse events for connecting conductors
 */
-class Terminal : public QGraphicsObject
+class Terminal : public QGraphicsObject, public PropertiesInterface
 {
 	Q_OBJECT
 
@@ -88,9 +90,9 @@ class Terminal : public QGraphicsObject
 		bool canBeLinkedTo(Terminal *);
 	
 		// methods related to XML import/export
-		static bool valideXml(QDomElement  &);
-		bool fromXml (QDomElement &);
-		QDomElement toXml (QDomDocument &) const;
+        bool valideXml(QDomElement  &) const override;
+        bool fromXml (const QDomElement &) override;
+        QDomElement toXml (QDomDocument &) const override;
 	
 	protected:
 		// methods related to events management