Passing a parameter with h:commandButton

Question

I have a a4j:commandButton which is supposed to redirect me to an appropriate "Edit" page based on an Id, which I wanted to pass as a parameter, something like this:

<h:commandButton action="/details.jsf?faces-redirect=true" value="details">
    <f:attribute name="id" value="#{bean.id}" />
</h:commandButton>

The problem is, it doesn't work. I also tried replacing f:attribute with "f:param name="id" value="#{bean.id}" ", but it also failed. The only thing I got to work is an outputLink:

<h:outputLink  value="/details.jsf">
    link
    <f:param name="id" value="#{bean.id}" />
</h:outputLink>

But I'm not really happy with a link, so is there a way to make the commandButton work?

Oh and I also have a bean which is supposed to get that "id" after the redirect:

@PostConstruct
public void init(){
    id= resolve("id");
}

Solution 1

Have a look at this article about communication in JSF, by BalusC

f:param only works with h:commandLink and h:outputLink.

You can use an input hidden:

<h:form>
    <h:commandButton action="/details.jsf?faces-redirect=true" value="details"/>
    <input type="hidden" name="id" value="#{bean.id}" />
</h:form>

And then in your faces-config, I guess is request scoped. If you use the annotations of JSF2, just translate this to the proper annotations.

<managed-bean>
    <managed-bean-name>bean</managed-bean-name>
    <managed-bean-class>mypackage.Bean</managed-bean-class>
    <managed-bean-scope>request</managed-bean-scope>
    <managed-property>
        <property-name>id</property-name>
        <value>#{param.id}</value>
    </managed-property>
</managed-bean>

You need obviously to have getters and setters for that field in the backing bean.

or try to "paint" the link as a button through CSS.

Solution 2

Unless my JSF is extremely rusty, the action attribute on a command button or command link is used to specify the outcome string defined in your faces-config-nav file, or it should point to a method on the bean which will return an outcome (or redirect/whatever).

In your case, if you want to redirect to another page... you should define that in your config file, as a navigation link (with redirect if necessary). Then in your action button you should have something like

<h:commandButton action="showDetails" value="details">

...

<navigation-case>
        <from-outcome>showDetails</from-outcome>
        <to-view-id>/details.jsf?faces-redirect=true</to-view-id>
</navigation-case>

As an aside, the <f:atribute> tag will work, but it will only set the attribute onto the component. So if you got a hold of the command button in your bean, you could be able to get the attribute value by name. To pass a request param, use the hidden field technique like pakore mentioned