feat: allow configuring the reverse_proxy_ttl with cache control directives

Author: 94noni

Resources/doc/reference/configuration/headers.rst

@@ -315,13 +315,16 @@ keeping previously set Vary options:
 ``reverse_proxy_ttl``
 """""""""""""""""""""
 
-**type**: ``integer``
+**type**: ``integer`` or ``array``
 
-Set a custom TTL header for reverse proxy time-outs not driven by
+If defined as integer, set a custom TTL header for reverse proxy time-outs not driven by
 ``s-maxage``. This keeps your ``s-maxage`` free for use with reverse proxies
 not under your control. The default header name is ``X-Reverse-Proxy-TTL`` but
 you can customize the header name as explained in the next section.
 
+
+If defined as an array, it follows logic of ``cache_control`` for supported directives.
+
 .. warning::
 
     This is a custom header. You need to set up your caching proxy to respect
@@ -347,6 +350,25 @@ section:
 
 This example adds the header ``X-Reverse-Proxy-TTL: 3600`` to your responses.
 
+Or as an array:
+
+.. code-block:: yaml
+
+    # app/config/config.yml
+    fos_http_cache:
+        cache_control:
+            rules:
+                -
+                    headers:
+                        reverse_proxy_ttl:
+                            public: true
+                            max_age: 3600
+                        cache_control:
+                            public: true
+                            max_age: 0
+
+This example adds the header ``X-Reverse-Proxy-TTL: max-age=3600, public`` to your responses.
+
 ``ttl_header``
 --------------
 

src/DependencyInjection/Configuration.php

@@ -333,9 +333,9 @@ private function addCacheControlSection(ArrayNodeDefinition $rootNode): void
                         ->end()
                         ->info('Set a default last modified timestamp if none is set yet. Value must be parseable by DateTime')
                     ->end()
-                    ->scalarNode('reverse_proxy_ttl')
+                    ->scalarNode('reverse_proxy_ttl') // TODO: make it handle scalar int (BC) or array (new)
                         ->defaultNull()
-                        ->info('Specify a custom time to live in seconds for your caching proxy. This value is sent in the custom header configured in cache_control.ttl_header.')
+                        ->info('Specify a custom time to live in seconds for your caching proxy. This value is sent in the custom header configured in cache_control.ttl_header. You can also specify a map like cache_control.')
                     ->end()
                     ->arrayNode('vary')
                         ->beforeNormalization()->ifString()->then(function ($v) {

src/EventListener/CacheControlListener.php

@@ -120,7 +120,16 @@ public function onKernelResponse(ResponseEvent $event): void
             && null !== $options['reverse_proxy_ttl']
             && !$response->headers->has($this->ttlHeader)
         ) {
-            $response->headers->set($this->ttlHeader, $options['reverse_proxy_ttl'], false);
+            $reverseProxyTtl = $options['reverse_proxy_ttl'];
+
+            if (is_int($reverseProxyTtl)) { // BC layer: simple mode as integer
+                $response->headers->set($this->ttlHeader, $reverseProxyTtl, false);
+            } elseif (is_array($reverseProxyTtl)) { // config mode: similar to cache_control
+                // only handle normal directives, no extra
+                $directives = array_intersect_key($reverseProxyTtl, $this->supportedDirectives);
+                $directives = array_map(function ($key) {return str_replace('_', '-', $key);}, $directives);
+                $response->headers->set($this->ttlHeader, implode(' ', $directives), false);
+            }
         }
 
         if (!empty($options['vary'])) {