Issue when converting GET request parameters on viewParam

Question

I'm trying to convert GET request parameters passed from another view like this:

<f:metadata>
    <f:viewParam name="id" 
                 value="#{targetViewBean.fooFromSourceView}" 
                 converter="fooConverter" 
                 converterMessage="Foo converter message"
                 required="true" requiredMessage="Foo required message"/>
    <f:viewAction action="#{targetViewBean.doSomethingWithFoo()}"/>
</f:metadata>

But only the Converter.getAsString(..., Object value) method is called and value is always null, even thou the GET parameter is really sent.

I found BalusC blog post about this and, AFAIK, I followed it to the letter. Still no good. Here's the full code:

Source view

<h:head>
    <title>Source view</title>
</h:head>
<h:body>
    <ul>
        <ui:repeat value="#{sourceViewBean.foos}" var="foo">
            <li>
                <h:link value="Foo \##{foo.id}" outcome="target-view">
                    <f:param name="id" value="#{foo.id}" />
                </h:link>
            </li>
        </ui:repeat>
    </ul>
</h:body>

Backing bean

@Named @ViewScoped
public class SourceViewBean implements Serializable {

    public Collection<Foo> getFoos() {
        return Db.INSTANCE.getFoos();
    }

    private static final long serialVersionUID = 1L;
}

Target view

<f:metadata>
    <f:viewParam name="id" 
                 value="#{targetViewBean.fooFromSourceView}" 
                 converter="fooConverter" 
                 converterMessage="Foo converter message"
                 required="true" requiredMessage="Foo required message"/>
    <f:viewAction action="#{targetViewBean.doSomethingWithFoo()}"/>
</f:metadata>
<h:head>
    <title>Target view</title>
</h:head>
<h:body>
    <h:outputText value="ID: #{targetViewBean.fooFromSourceView.id}" />
</h:body>

Target view backing bean

@Named 
@ViewScoped
public class TargetViewBean implements Serializable {
    private Foo fooFromSourceView;

    public void doSomethingWithFoo() {
        System.out.println("Foo is here? " + fooFromSourceView != null);
    }

    public Foo getFooFromSourceView() {
        return fooFromSourceView;
    }

    public void setFooFromSourceView(Foo fooFromSourceView) {
        this.fooFromSourceView = fooFromSourceView;
    }

    private static final long serialVersionUID = 1L;
}

The converter

@FacesConverter(value = "fooConverter")
public class FooConverter implements Converter {
    @Override
    public Object getAsObject(
            FacesContext context, UIComponent component, String value) {
        if (value == null || !value.matches("\\d+")) {
            return null;
        }

        for (Foo foo : Db.INSTANCE.getFoos()) {
            if (foo.getId().equals(Integer.parseInt(value))) {
                return foo;
            }
        }
        throw new ConverterException(new FacesMessage("No Foo found!"));
    }

    @Override
    public String getAsString(
            FacesContext context, UIComponent component, Object value) {
        if (!(value instanceof Foo) || ((Foo) value).getId() == null) {
            return null;
        }

        return ((Foo) value).getId().toString();
    }
}

Answer 1

I was able to find the problem after taking a look at the actual code you sent. The issue is not with the converter. It's with the xml namespaces at the top of your project. For instance, in source-view.xml you have

 xmlns:h="http://xmlns.jcp.org/jsf/html"
 xmlns:ui="http://xmlns.jcp.org/jsf/facelets"
 xmlns:f="http://xmlns.jcp.org/jsf/core"

But they should be

xmlns:h="http://java.sun.com/jsf/html"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:f="http://java.sun.com/jsf/core">

And target-view.xhtml should be

xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core">

GlassFish seems to change the namespaces for some reason. I didn't try to find out why it behaves like that though so keep that in mind. Anyway, once I changed it, the correct phases were being outputted in GlassFish's output window. So go and make the necessary change where needed.

Note: In case you are wondering why you are getting the following error

The metadata component needs to be nested within a f:metadata tag. Suggestion: enclose the necessary components within <f:metadata> 

This seems to be a reported issue with JSF 2.2

Also, I'm not sure why your h:link is nested inside an h:form. It's not needed.

UPDATE Seems like some of the taglibs are not fully functional or am I reading this wrong ?

https://java.net/jira/browse/JAVASERVERFACES-2868