Problem with updating value in TableColumn Cell

My problem is a bit ambiguous (I don't know if it's a bug or not), i want the user to enter any value he wants, as long as it's not empty, so i created a method to check the input which returns the previous value if the input string is empty, and this is where the problem occurs, if the user clears the cell and presses the enter key, the cell displays nothing, until I click on it, here's a functional example of my project :

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableColumn.CellEditEvent;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.TextFieldTableCell;
import javafx.scene.layout.AnchorPane;
import javafx.stage.Stage;
public class Launcher extends Application
{
@Override
public void start(Stage stage) throws Exception
{
AnchorPane root = new AnchorPane();
TableView<Apprenant> table = new TableView<>();
table.setPrefWidth(800);
table.setEditable(true);
TableColumn<Apprenant, String> nom = new TableColumn<>("Noms");
nom.setPrefWidth(100);
TableColumn<Apprenant, String> prenom = new TableColumn<>("Prenoms");
prenom.setPrefWidth(100);
nom.setCellValueFactory(var -> var.getValue().nomProperty());
prenom.setCellValueFactory(var -> var.getValue().prenomProperty());
nom.setCellFactory(TextFieldTableCell.forTableColumn());
nom.setOnEditCommit((CellEditEvent<Apprenant, String> evt)->{
Apprenant app = table.getSelectionModel().getSelectedItem();
app.setNom(check(evt.getNewValue(),app.nomProperty().get()));
/*THE ONLY WAY TO DISPLAY THE UPDATED VALUE*/
//nom.setVisible(false); 
//nom.setVisible(true);
});
table.getColumns().add(nom);
table.getColumns().add(prenom);
table.getItems().add(new Apprenant("monNom","monPrenom"));
root.getChildren().add(table);
Scene scene = new Scene(root,1200,800);
stage.setScene(scene);
stage.show();
}
private static String check(String valeur,String prev)
{
if(valeur.isEmpty())
{	
return prev;
}
else
{
return valeur;
}
}
public static void main(String[] args)
{
launch(args);
}
}

The model :

import javafx.beans.property.SimpleStringProperty;
import javafx.beans.property.StringProperty;
public class Apprenant
{
private StringProperty nom = new SimpleStringProperty();
private StringProperty prenom = new SimpleStringProperty();
public Apprenant(String nom, String prenom)
{
this.nom.set(nom);
this.prenom.set(prenom);
}
public StringProperty nomProperty()
{
return nom;
}
public StringProperty prenomProperty()
{
return prenom;
}
public void setNom(String nom)
{
this.nom.set(nom);
}
public void setPrenom(String prenom)
{
this.prenom.set(prenom);
}
}

So my question is simple, how to update the cell without having to use the setVisible method as indicated above or the updateItem function ? I found this topic somewhat similar to mine but without any reference to my problem.

The editing mechanisms for virtualized controls in JavaFX are somewhat opaque...

Instead of capturing the editCommit event, which happens after an edit has been committed, override the commitEdit() method of the cell:

        nom.setCellFactory(tc -> new TextFieldTableCell<>(TextFormatter.IDENTITY_STRING_CONVERTER) {
@Override
public void commitEdit(String newValue) {
if (newValue.isEmpty()) {
cancelEdit();
} else {
super.commitEdit(newValue);
}
}
});
//        nom.setCellFactory(TextFieldTableCell.forTableColumn());
//        nom.setOnEditCommit((CellEditEvent<Apprenant, String> evt)->{
//            
//            Apprenant app = table.getSelectionModel().getSelectedItem();
//            app.setNom(check(evt.getNewValue(),app.getNom().get()));
//    
//            /*THE ONLY WAY TO DISPLAY THE UPDATED VALUE*/
//            //nom.setVisible(false); 
//            //nom.setVisible(true);
//        });

This might be considered something of a hack, as it's not really the cell's job to validate data, but it's probably the path of least resistance given the API. The "correct" way to do this would probably be to perform the validation in the model, which (as far as I can see) would involve subclassing StringPropertyBase to support the validation.