From 270de59b0dfe9670e6fd75ff034385289b37d072 Mon Sep 17 00:00:00 2001
From: Michel Hunziker <info@michelhunziker.com>
Date: Thu, 20 Aug 2015 15:41:31 +0200
Subject: [PATCH] Move cache prevention logic to the Cache-Control object

---
 src/CacheUtil.php                        | 19 +++++++++++--------
 src/Header/ResponseCacheControl.php      | 11 +++++++++++
 test/Header/ResponseCacheControlTest.php | 11 +++++++++++
 3 files changed, 33 insertions(+), 8 deletions(-)

diff --git a/src/CacheUtil.php b/src/CacheUtil.php
index f025c38..46df371 100644
--- a/src/CacheUtil.php
+++ b/src/CacheUtil.php
@@ -40,10 +40,11 @@ class CacheUtil
      */
     public function withCache(ResponseInterface $response, $public = false, $maxAge = 600)
     {
-        $type = $public ? 'public' : 'private';
-        $age = max(0, (int) $maxAge);
+        $control = new ResponseCacheControl();
+        $control = $public ? $control->withPublic() : $control->withPrivate();
+        $control = $control->withMaxAge($maxAge);
 
-        return $this->withCacheControl($response, $type . ', max-age=' . $age);
+        return $this->withCacheControl($response, $control);
     }
 
     /**
@@ -58,7 +59,10 @@ public function withCache(ResponseInterface $response, $public = false, $maxAge
      */
     public function withCachePrevention(ResponseInterface $response)
     {
-        return $this->withCacheControl($response, 'no-cache, no-store, must-revalidate');
+        $control = new ResponseCacheControl();
+        $control = $control->withCachePrevention();
+
+        return $this->withCacheControl($response, $control);
     }
 
     /**
@@ -154,17 +158,16 @@ public function withLastModified(ResponseInterface $response, $time)
     }
 
     /**
-     * Method to add a Cache-Control header to the provided PSR-7 message. The cache control
-     * parameter can either be a string or a Cache-Control object.
+     * Method to add a Cache-Control header to the provided PSR-7 message.
      *
      * @link https://tools.ietf.org/html/rfc7234#section-5.2
      *
      * @param MessageInterface $message PSR-7 message to add the Cache-Control header to
-     * @param string|CacheControl $cacheControl Cache-Control string or object
+     * @param CacheControl $cacheControl Cache-Control object to add to the message
      * @return MessageInterface The PSR-7 message with the added Cache-Control header
      * @throws InvalidArgumentException If the Cache-Control header is invalid
      */
-    public function withCacheControl(MessageInterface $message, $cacheControl)
+    public function withCacheControl(MessageInterface $message, CacheControl $cacheControl)
     {
         return $message->withHeader('Cache-Control', (string) $cacheControl);
     }
diff --git a/src/Header/ResponseCacheControl.php b/src/Header/ResponseCacheControl.php
index b8cbbad..98ed680 100644
--- a/src/Header/ResponseCacheControl.php
+++ b/src/Header/ResponseCacheControl.php
@@ -177,6 +177,17 @@ public function hasProxyRevalidate()
         return $this->hasDirective('proxy-revalidate');
     }
 
+    /**
+     * Convenience method to set flags which should prevent the client from caching.
+     * Adds `no-cache, no-store, must-revalidate`.
+     *
+     * @return static
+     */
+    public function withCachePrevention()
+    {
+        return $this->withNoCache()->withNoStore()->withMustRevalidate();
+    }
+
     /**
      * Sets the flag for the public and private directives.
      *
diff --git a/test/Header/ResponseCacheControlTest.php b/test/Header/ResponseCacheControlTest.php
index 8915b86..e525cae 100644
--- a/test/Header/ResponseCacheControlTest.php
+++ b/test/Header/ResponseCacheControlTest.php
@@ -216,4 +216,15 @@ public function testHasProxyRevalidate()
         $control = $this->getControlWithHasFlag('proxy-revalidate');
         $this->assertReturn($control->hasProxyRevalidate());
     }
+
+    /**
+     * @covers Micheh\Cache\Header\ResponseCacheControl::withCachePrevention
+     */
+    public function testWithCachePrevention()
+    {
+        $control = $this->cacheControl->withCachePrevention();
+        $directives = ['no-cache' => true, 'no-store' => true, 'must-revalidate' => true];
+
+        $this->assertAttributeSame($directives, 'directives', $control);
+    }
 }