Passing values from Page to Bean in JSF

refer to :
http://gik.firetrot.com/index.php/2013/07/19/passing-values-from-page-to-bean-in-jsf/


There are three ways to pass values from page to JSF ManagedBean:

1. Passing value with f:param tag – using action attribute
2. Passing value with f:attribute tag – using actionListener attribute
3. Passing value with f:setPropertyActionListener tag – no need for additional dealing, value allplies directly to bean property!

example : 

case 1:

<p:commandButton value="Pass Param" action="#{PassParamBean.passParam}">

        <f:param name="someParamHolder" value="THIS is VALUE_OF_PARAM !!!" />    </p:commandButton>

case 2:

<p:commandButton value="Pass Attribute" actionListener="#{PassParamBean.passAttributeListener}"

        ajax="true" update="someAttributeId">

        <f:attribute name="someAttributeHolder" value="THIS is VALUE_OF_ATTRIBUTE !!!" />    </p:commandButton>

case 3: 

 <p:commandButton value="Pass Property"

       ajax="true" update="somePropertyId">

       <f:setPropertyActionListener target="#{PassParamBean.someProperty}" 

           value="THIS is VALUE_OF_PROPERTY !!!" />

</p:commandButton>

in managed  bean:

 package passvalue;

import java.io.Serializable;

import java.util.Map;

import javax.faces.component.UIComponent;

import javax.faces.context.ExternalContext;

import javax.faces.context.FacesContext;

import javax.faces.event.ActionEvent;

public class PassParamBean implements Serializable {

    private static final String DEFAULT_OUTCOME = "pass_value";

    private String someParam;

    private String someAttribute;

    private String someProperty;

    public String passParam() {

        FacesContext facesContext = FacesContext.getCurrentInstance();

        ExternalContext externalContext = facesContext.getExternalContext();

        Map<String, String> params = externalContext.getRequestParameterMap();

        someParam = params.get("someParamHolder");

        return DEFAULT_OUTCOME;

    }

    public void passAttributeListener(ActionEvent event) {

        UIComponent component = event.getComponent();

        Map<String, Object> attrs = component.getAttributes();

        someAttribute = (String) attrs.get("someAttributeHolder");

    }

// setters and getters

}