jsfactiononloadmanaged-bean

Invoke JSF managed bean action on page load

Is there a way to execute a JSF managed bean action when a page is loaded?

If that's relevant, I'm currently using JSF 1.2.

Solution

  • JSF 1.0 / 1.1

    Just put the desired logic in the constructor of the request scoped bean associated with the JSF page. 

    public Bean() {
    // Do your stuff here.
}

    JSF 1.2 / 2.x

    Use @PostConstruct annotated method on a request or view scoped bean. It will be executed after construction and initialization/setting of all managed properties and injected dependencies.

    @PostConstruct
public void init() {
    // Do your stuff here.
}

    This is strongly recommended over constructor in case you're using a bean management framework which uses proxies, such as CDI, because the constructor may not be called at the times you'd expect it.

    JSF 2.0 / 2.1

    Alternatively, use <f:event type="preRenderView"> in case you intend to initialize based on <f:viewParam> too, or when the bean is put in a broader scope than the view scope (which in turn indicates a design problem, but that aside). Otherwise, a @PostConstruct is perfectly fine too.

    <f:metadata>
    <f:viewParam name="foo" value="#{bean.foo}" />
    <f:event type="preRenderView" listener="#{bean.onload}" />
</f:metadata>

    public void onload() { 
    // Do your stuff here.
}

    JSF 2.2+

    Alternatively, use <f:viewAction> in case you intend to initialize based on <f:viewParam> too, or when the bean is put in a broader scope than the view scope (which in turn indicates a design problem, but that aside). Otherwise, a @PostConstruct is perfectly fine too.

    <f:metadata>
    <f:viewParam name="foo" value="#{bean.foo}" />
    <f:viewAction action="#{bean.onload}" />
</f:metadata>

    public void onload() { 
    // Do your stuff here.
}

    Note that this can return a String navigation case if necessary. It will be interpreted as a redirect (so you do not need a ?faces-redirect=true here).

    public String onload() { 
    // Do your stuff here.
    // ...
    return "some.xhtml";
}

    See also: