MessageDialog is triggering handler twice

MessageDialog is triggering signals twice

import QtQuick 2.2
import QtQuick.Dialogs 1.1

.....

MessageDialog {
id: id_dialogDelete
title: qsTr("Warning");
icon: StandardIcon.Warning
text: qsTr("Are you sure?")
standardButtons: StandardButton.Yes | StandardButton.No
Component.onCompleted: visible = true

onYes:

}

Triggers yes() signal two times and the result is:

DELETE
DELETE