Merge pull request #84 from taniwallach/add_cache_control_expires

Add Cache-control and Expires headers for files under webwork2_files

lib/RenderApp.pm

@@ -69,6 +69,35 @@ sub startup {
 		});
 	}
 
+	# Add Cache-Control and Expires headers to static content from webwork2_files
+	if (my $STATIC_EXPIRES = $self->config('STATIC_EXPIRES')) {
+	    $STATIC_EXPIRES = int( $STATIC_EXPIRES );
+	    my $cache_control_setting = "max-age=$STATIC_EXPIRES";
+	    my $no_cache_setting = 'max-age=1, no-cache';
+	    $self->hook(after_dispatch => sub {
+		my $c = shift;
+
+		# Only process if file requested is under webwork2_files
+		return unless ($c->req->url->path =~ '^/webwork2_files/');
+
+		if ($c->req->url->path =~ '/tmp/renderer') {
+		    # Treat problem generated files as already expired.
+		    # They should not be cached.
+		    $c->res->headers->cache_control( $no_cache_setting );
+		    $c->res->headers->header(Expires =>
+		        Mojo::Date->new(time - 86400) # expired 24 hours ago
+		    );
+		} else {
+		    # Standard "static" files.
+		    # They can be cached
+		    $c->res->headers->cache_control( $cache_control_setting );
+		    $c->res->headers->header(Expires =>
+		        Mojo::Date->new(time + $STATIC_EXPIRES)
+			);
+		}
+	    });
+	}
+
 	# Models
 	$self->helper(newProblem => sub { shift; RenderApp::Model::Problem->new(@_) });
 

render_app.conf.dist

@@ -6,6 +6,7 @@
   webworkJWTsecret => 'private',
   SITE_HOST => 'http://localhost:3000',
   CORS_ORIGIN => '*',
+  STATIC_EXPIRES => 86400,
   STRICT_JWT => 0,
   hypnotoad => {
     listen => ['http://*:3000'],