Showing Object Properties in a TableView

This post is not to talk about any specific app but to show a simple How-To with TableView.
 Show values in a table in JavaFX is easy. You can show an object property with a few lines of code since we have classes that allows you to produce cells that read directly from the object. For example, let's say we have a class Person that contains two properties:

 

public class Person {
 private String name;
 private int id;
       //getters, setters..
}

If you want to create to columns to show the id and name properties, you need to create two columns and inform each column a PropertyValueFactory object instance:

TableView tableView = new TableView();
TableColumn idColumn = new TableColumn("Id");
idColumn.setCellValueFactory(new PropertyValueFactory("id"));
TableColumn nameColumn = new TableColumn("Name");
nameColumn.setCellValueFactory(new PropertyValueFactory("name"));
tableView.getColumns().addAll(idColumn, nameColumn);

Let's complicate a bit! What's if my object Person contains other object, for example, City and we want to show a City property? If we try to add a column for the property city with the following code:

 
TableColumn cityColumn = new TableColumn("City");
cityColumn.setCellValueFactory(new PropertyValueFactory("city"));

But it will not show any city property, it will actually show the toString method return:

Obviously you can go to City class code and override this method. Let't get the things a bit more complicated. This time let's say that you need to show a property from a City property, for example, State.

Person - City - State

Well, you can read things in the method toString of the object City, but this is not the best solution. One alternative is to set a CellValueFactory in your column using a Callback class.
. With this approach we can read any property we want from the Person class and return it to be showed in the table. It's pretty easy to use it:

TableColumn stateColumn = new TableColumn("State");
stateColumn.setCellValueFactory(new Callback, ObservableValue>() {    
    @Override    
    public ObservableValue call(CellDataFeatures c) {
        return new SimpleStringProperty(c.getValue().getCity().getState().getName());
    }
});

That's basically it what I wanted to show in this post. The entire test application code:

package org.jesuino.javafx.tableview.cellfactory;

import java.util.Arrays;
import java.util.List;

import javafx.application.Application;
import javafx.beans.property.SimpleStringProperty;
import javafx.beans.value.ObservableValue;
import javafx.scene.SceneBuilder;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.TableColumn.CellDataFeatures;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.StackPaneBuilder;
import javafx.stage.Stage;
import javafx.util.Callback;

import org.jesuino.javafx.tableview.cellfactory.model.City;
import org.jesuino.javafx.tableview.cellfactory.model.Person;
import org.jesuino.javafx.tableview.cellfactory.model.State;

public class Main extends Application {

 TableView tableViewRef;

 public static void main(String[] args) {
  launch();
 }

 @Override
 public void start(Stage stage) throws Exception {

  stage.setScene(SceneBuilder
    .create()
    .width(420)
    .height(200)
    .root(StackPaneBuilder.create()
      .children(tableViewRef = createTableView()).build())
    .build());
  stage.setTitle("Testing Table View Cell Factory");
  stage.show();

  tableViewRef.getItems().addAll(mockPersonItems());
 }

 @SuppressWarnings("unchecked")
 private TableView createTableView() {
  TableView tableView = new TableView();

  TableColumn idColumn = new TableColumn(
    "Id");
  idColumn.setCellValueFactory(new PropertyValueFactory(
    "id"));
  idColumn.setMinWidth(80);

  TableColumn nameColumn = new TableColumn(
    "Name");
  nameColumn
    .setCellValueFactory(new PropertyValueFactory(
      "name"));
  nameColumn.setMinWidth(150);

  TableColumn cityColumn = new TableColumn(
    "City");
  cityColumn
    .setCellValueFactory(new PropertyValueFactory(
      "city"));
  cityColumn.setMinWidth(150);

  TableColumn stateColumn = new TableColumn(
    "State");
  stateColumn
    .setCellValueFactory(new Callback, ObservableValue>() {
     @Override
     public ObservableValue call(
       CellDataFeatures c) {
      return new SimpleStringProperty(c.getValue().getCity()
        .getState().getName());
     }
    });

  tableView.getColumns().addAll(idColumn, nameColumn, cityColumn,
    stateColumn);

  return tableView;
 }

 private List mockPersonItems() {
  State sp = new State("São Paulo", "SP");

  City saoJoseDosCampos = new City(sp, "São José dos Campos");
  City taubate = new City(sp, "Taubaté");
  City jacarei = new City(sp, "Jacareí");

  Person p1 = new Person("William Antônio Siqueira", 1, saoJoseDosCampos);
  Person p2 = new Person("Maria", 2, saoJoseDosCampos);
  Person p3 = new Person("João", 3, taubate);
  Person p4 = new Person("Joana", 4, jacarei);

  return Arrays.asList(p1, p2, p3, p4);
 }
}