private void documentDataModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
DocumentDataModel dataModel = sender as DocumentDataModel;
if (dataModel.State == DataModel.ModelState.Invalid && this.prop_DocumentChanged)
{
return;
}
this.Document.Text = dataModel.SaveDocument();
this.IsDirty = false;
this.prop_DocumentChanged = false;
}