JSF Passing Parameters via Method Expression

In this example we’ll talk about passing parameters via method expression. When you need to pass a parameter to a managed bean method, you can just pass the parameter between brackets. You can pass numeric values, String values and Objects.

Passing parameters via method expression

Just a simple POJO.

package com.memorynotfound;

public class Course {

    private Integer id;
    private String name;

    public Course(Integer id, String name) {
        this.id = id;
        this.name = name;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

The delete() method has the Course class as a parameter. We can simply reference a Course object from our view to the managed bean.

package com.memorynotfound;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

@ManagedBean
@SessionScoped
public class CourseBean implements Serializable {

    static List<Course> courseList = new ArrayList<Course>();

    public CourseBean(){
        courseList.add(new Course(1, "Programming JSF"));
        courseList.add(new Course(2, "Programming CDI"));
        courseList.add(new Course(3, "Programming Facelets"));
    }

    public List<Course> getCourses(){
        return courseList;
    }

    public String delete(Course course){
        courseList.remove(course);
        return null;
    }
}

Passing the parameter via method expressions

We have a data table which passes the Course object in every column in order to have a reference of which object to delet.

<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:h="http://xmlns.jcp.org/jsf/html">
<h:body>

    <h1>JSF Method Expression Example</h1>

    <h:form>
        <h:dataTable id="courses" var="course" value="#{courseBean.courses}">
            <h:column>
                <h:outputText value="#{course.name}"/>
            </h:column>
            <h:column>
                <h:commandLink value="delete" action="#{courseBean.delete(course)}"/>
            </h:column>
        </h:dataTable>
    </h:form>

</h:body>
</html>

Demo

URL: localhost:8080/jsf-method-expression/

jsf passing parameters via method expression

References

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