Question

I have a JSF 1.2 / Seam 2.2.2 application. I have button and on click of the button, I run validations on the objects in current page, query for some dependent objects and run validation. If the validation passes, then I need to redirect the user to the new page. Otherwise, I need to display validation errors in the same page. Below code works fine and error message is displayed. But how to I redirect to a new page?

<h:messages id="errorMsg" errorClass="errorMessages" />
<a4j:commandButton action="#{myController.shouldRedirectToNewPage()}"
                value="Button" styleClass="button" />

public void shouldRedirectToNewPage() {
    //Run validation on objects in the current page
    //Query for dependent objects and run validation
    if(validationFails) {
       facesContext.addMessage(null, new FacesMessage(FacesMessage.SEVERITY_ERROR,
          "ERROR MESSAGE", null)); 
       return;
   }
}

Answer 1

Either use ExternalContext#redirect():

public void shouldRedirectToNewPage() throws IOException {
    // ...

    if (validationFails) {
        facesContext.addMessage(null, new FacesMessage(FacesMessage.SEVERITY_ERROR, "ERROR MESSAGE", null));
    } else {
        facesContext.getExternalContext().redirect("otherpage.jsf");
    }
}

or return a navigation case string the usual way:

public String shouldRedirectToNewPage() {
    // ...

    if (validationFails) {
        facesContext.addMessage(null, new FacesMessage(FacesMessage.SEVERITY_ERROR, "ERROR MESSAGE", null));
        return null;
    } else {
        return "otherpage";
    }
}

with the following in faces-config.xml:

<navigation-case>
    <from-outcome>otherpage</from-outcome>
    <to-view-id>/otherpage.jsf</to-view-id>
    <redirect/>
</navigation-case>

(note the <redirect/>, this makes it a redirect instead of a (default) forward)

---

Unrelated to the concrete problem, doing validation inside the action method isn’t necessarily the best practice. It should be done by a Validator. If it throws a ValidatorException, then the action method simply won’t be invoked.