ahn94

The two easiest ways of doing it for small applications are :

Do not specify the fx:controller in the fxml. Create a controller instance by passing data to it and then pass it to the FXMLLoader.

Specify the fx:controller in the fxml. Fetch the controller instance from the FXMLLoader and pass the data to the controller.

The following are the examples for both the above said types. Each of the example have 3 components :

FXML - The FXML file, which doesn't have the fx:controller declaration for the first type and has it for the second type.
Controller - Has a constructor for the first type. Has setter methods for the second type.

ahn94

// Use Gists to store code you would like to remember later on
console.log(window); // log the "window" object to the console

ahn94

import javafx.application.Application;
import javafx.application.Platform;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.scene.layout.*;
import javafx.stage.Stage;

ahn94

import javafx.application.Application;
import javafx.application.Platform;
import javafx.collections.ObservableList;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.stage.Stage;

ahn94

import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.stage.Stage;

public class Main extends Application {

ahn94

import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.stage.Stage;

public class Main extends Application {

ahn94

import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.*;
import javafx.scene.layout.*;
import javafx.stage.Stage;

public class Main extends Application {

ahn94

    private boolean isInt(TextField input, String message){
        try {
            int age = Integer.parseInt(input.getText());
            System.out.println("user is: " + age);
            return true;
        } catch (NumberFormatException e){
            System.out.println("Error: " + message + " is not a number");
            return false;
        }
    }

ahn94

GridPane grid = new GridPane();
        grid.setPadding(new Insets(10, 10, 10, 10));
        grid.setVgap(8);
        grid.setHgap(10);

        Label username = new Label("Username");
        GridPane.setConstraints(username, 0, 0);

        //Name input
        TextField nameInput = new TextField();

ahn94

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package fxzoomtest01;

import javafx.animation.KeyFrame;
import javafx.animation.KeyValue;
import javafx.animation.ScaleTransition;
import javafx.animation.Timeline;