FXML: Alternate Uses

Question

It is possible to use FXML to load non-GUI objects into memory? For example, I am creating a simple "voting" software for my school. All it needs is the list of "elective-posts" and the corresponding candidates along with other things like sets of "properties" of the posts and candidates.

What I want to do is, that I write the data in a FXML file and then load it using a FXMLLoader.

Answer 1

Yes, FXML can be used to create arbitrary objects. You'd define the objects just like you would any GUI object. You just have to make sure that:

• You follow Java getter/setter naming conventions
• If you have a setter named setField then in the FXML the attribute would be field="value"
• Unless you are using JavaFX properties the binding syntax won't work
• If you don't have a setter but you can set the field via a constructor (or you don't have a default constructor) then you have to annotate the constructor parameters with NamedArg

Here's a small example.

Animal.java

package com.example;

import javafx.beans.NamedArg;

public class Animal {

    private final String name;
    private boolean housePet;

    public Animal(@NamedArg("name") String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public boolean isHousePet() {
        return housePet;
    }

    public void setHousePet(boolean housePet) {
        this.housePet = housePet;
    }

    @Override
    public String toString() {
        return "Animal[name=" + name + ", housePet=" + housePet + "]";
    }

}

Main.java

package com.example;

import java.io.IOException;
import java.util.List;
import javafx.fxml.FXMLLoader;

public class Main {

    public static void main(String[] args) throws IOException {
        List<Animal> list = FXMLLoader.load(Main.class.getResource("Main.fxml"));
        list.forEach(System.out::println);
    }

}

Main.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import com.example.Animal?>
<?import java.util.ArrayList?>

<ArrayList xmlns="http://javafx.com/javafx/10.0.2" xmlns:fx="http://javafx.com/fxml/1">

    <Animal name="Cat" housePet="true"/>
    <Animal name="Dog" housePet="true"/>
    <Animal name="Bear" housePet="false"/>
    <Animal name="Wolf" housePet="false"/>

    <!-- Another way of declaring an Animal -->

    <Animal>
        <name>Snake</name>
        <housePet>true</housePet>
    </Animal>

</ArrayList>

Running Main prints the following:

Animal[name=Cat, housePet=true]
Animal[name=Dog, housePet=true]
Animal[name=Bear, housePet=false]
Animal[name=Wolf, housePet=false]
Animal[name=Snake, housePet=true]