How can I set the Cache-Control header for every response in Catalyst?

Question

It seems that by default Catalyst does not output Cache-Control:, etc. headers. I know I can output them in a given controller method like this:

$c->response->headers->last_modified(time);
$c->response->headers->expires(time + $self->{cache_time});
$c->response->headers->header(cache_control => "public, max-age=$self->{cache_time}");

It'd get pretty painful doing that in each method, though! What I'd prefer is:

• A default set of headers (expires now, last modified now, cache-control: no-cache, pragma: no-cache)
• A way to, per-method, override the default.

Is there a good way to accomplish this?

Answer 1

Update: Based on your response to my earlier suggestion, I decided to bite the bullet and look at the Catalyst docs. It seems to me, the place to do this is in:

  sub end : Private {
    my ( $self, $c ) = @_;

    # handle errors etc.

    if ( $c->res->body ) {
        if ( "some condition" ) {
            set_default_response_headers( $c->response->headers );
            return;
        }
        else {
            do_something_else();
            return;
        }
    }
    $c->forward( 'MyApp::View::TT' ); # render template
}

Earlier response: I do not use Catalyst, but couldn't you just write a sub for your application?

sub set_default_response_headers {
    my ($h) = @_;
    $h->last_modified(time);
    $h->expires(time + $self->{cache_time});
    $h->header(cache_control => "public, max-age=$self->{cache_time}");
    return $h;    
}

Call with set_default_response_headers( $c->response->headers ).

Answer 2

derobert:

Excellent question. I covered exactly this in an article for the Catalyst advent calendar.

Basically you create a stash variable that defines your cache time for the given action, and then you process it in your Root end routine. See the article for all the details.

JayK