Hit a bean method and redirect on a GET request
I'm using JSF 2 and PrimeFaces 2.1 on GlassFish.
I have a page that is intended to allow people to perform an action after following a callback URL (e.g. as link embedded in email or as callback URL parameter of some external authentication or payment service). In my case I need to reset the password. The callback URL has a token GET parameter like so:
http://example.com/app/resetPasswordForm.jsf?token=abc123
On page load of resetPasswordForm.jsf, I need to check if the token is valid and redirect to the main app screen if it's not valid.
My thinking is to have a bean method like:
public String resetPasswordHandler.showResetForm(String token) {
if /* token is valid */ {
return "resetPasswordForm.jsf";
} else {
return "main.jsf";
}
}
But how would I cause that method to get hit on page load?
Not sure how to proceed -- suggestions are welcome.
Answer
Use <f:viewAction> to trigger a bean method before rendering of the view and simply return a navigation outcome (which will implicitly be treated as a redirect).
E.g.
<f:metadata>
<f:viewParam name="token" value="#{authenticator.token}" />
<f:viewAction action="#{authenticator.check}" />
</f:metadata>
with
@ManagedBean
@RequestScoped
public class Authenticator {
private String token;
public String check() {
return isValid(token) ? null : "main.jsf";
}
// Getter/setter.
}
If you're not on JSF 2.2 yet, then you can use the <f:event type="preRenderView"> workaround in combination with ExternalContext#redirect().
<f:metadata>
<f:viewParam name="token" value="#{authenticator.token}" />
<f:event type="preRenderView" listener="#{authenticator.check}" />
</f:metadata>
with
@ManagedBean
@RequestScoped
public class Authenticator {
private String token;
public void check() throws IOException {
if (!isValid(token)) {
FacesContext.getCurrentInstance().getExternalContext().redirect("main.jsf");
}
}
// Getter/setter.
}