Inserting element in an arraylist to render empty line - jsf

Question

I am using primefaces on the frontend and populating a selectOneList using an arraylist in my backing bean
I want to have the array list separated by new lines to make some logical separations
How can I add an element to an ArrayList that will be rendered as an empty line ?

Answer 1

The following code will help you to achieve the functionality you want, that is to enter some empty line in <p:selectOneListBox>. Now I am not sure if it is a feature of this component that to squeeze out the empty string. So "" will not work.
This is a sample managed bean:
package app.so.dev.web.controller;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import javax.annotation.PostConstruct;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.ViewScoped;
import app.so.dev.web.model.Student;
#ManagedBean(name = "so15350373")
#ViewScoped
public class SO15350373 implements Serializable{
private static final long serialVersionUID = 2190171095461884759L;
private List<Student> students;
private int selected;
#PostConstruct
public void init() {
students = new ArrayList<Student>();
students.add(new Student(1, "Student 1"));
students.add(new Student(2, " "));
students.add(new Student(3, "Student 3"));
students.add(new Student(4, " "));
students.add(new Student(5, "Student 5"));
students.add(new Student(6, "Student 6"));
}
public List<Student> getStudents() {
return students;
}
public void setStudents(List<Student> students) {
this.students = students;
}
public int getSelected() {
return selected;
}
public void setSelectedStudent(int selected) {
this.selected = selected;
}
}
The Student is a simple POJO having two field id and name. For the sake of brevity, I am not showing this class :P.
And this is the xhtml:
<ui:composition xmlns="http://www.w3.org/1999/xhtml" xmlns:ui="http://java.sun.com/jsf/facelets" xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core" xmlns:p="http://primefaces.org/ui" template="/WEB-INF/templates/globalTemplate.xhtml">
<ui:define name="title">15350373</ui:define>
<ui:define name="content">
<h:form>
<p:selectOneListbox value="#{so15350373.selected}" id="list">
<f:selectItems value="#{so15350373.students}" var="student" itemLabel="#{student.name}" itemValue="#{student.id}" />
</p:selectOneListbox>
</h:form>
</ui:define>
</ui:composition>