From 13341c323d43eb47562d8ae72eae730e3e0e2cee Mon Sep 17 00:00:00 2001
From: Andy Miller <rhuk@mac.com>
Date: Wed, 26 Jul 2017 12:33:35 -0600
Subject: [PATCH] Added cache-control property #1591

---
 CHANGELOG.md                         |  6 ++++++
 system/blueprints/config/system.yaml |  6 ++++++
 system/config/system.yaml            |  1 +
 system/src/Grav/Common/Grav.php      | 11 ++++++++++-
 system/src/Grav/Common/Page/Page.php | 20 ++++++++++++++++++++
 5 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index eefb41e0e..dd094ed19 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,9 @@
+# v1.3.2
+## 07/xx/2017
+
+1. [](#new)
+    * Added a new `cache-control` system and page level property [#1591](https://github.com/getgrav/grav/issues/1591)
+
 # v1.3.1
 ## 07/19/2017
 
diff --git a/system/blueprints/config/system.yaml b/system/blueprints/config/system.yaml
index c9b959e86..4021255f3 100644
--- a/system/blueprints/config/system.yaml
+++ b/system/blueprints/config/system.yaml
@@ -377,6 +377,12 @@ form:
                     validate:
                         type: number
                         min: 1
+                pages.cache_control:
+                    type: text
+                    size: medium
+                    label: PLUGIN_ADMIN.CACHE_CONTROL
+                    help: PLUGIN_ADMIN.CACHE_CONTROL_HELP
+                    placeholder: 'e.g. public, max-age=31536000'
                 pages.last_modified:
                     type: toggle
                     label: PLUGIN_ADMIN.LAST_MODIFIED
diff --git a/system/config/system.yaml b/system/config/system.yaml
index 5d6ca443f..9f25ff9b6 100644
--- a/system/config/system.yaml
+++ b/system/config/system.yaml
@@ -53,6 +53,7 @@ pages:
   types: [txt,xml,html,htm,json,rss,atom]        # list of valid page types
   append_url_extension: ''                       # Append page's extension in Page urls (e.g. '.html' results in /path/page.html)
   expires: 604800                                # Page expires time in seconds (604800 seconds = 7 days)
+  cache_control:                                 # Can be blank for no setting, or a valid `cache-control` text value
   last_modified: false                           # Set the last modified date header based on file modification timestamp
   etag: false                                    # Set the etag header tag
   vary_accept_encoding: false                    # Add `Vary: Accept-Encoding` header
diff --git a/system/src/Grav/Common/Grav.php b/system/src/Grav/Common/Grav.php
index a260ec95f..ef2125e33 100644
--- a/system/src/Grav/Common/Grav.php
+++ b/system/src/Grav/Common/Grav.php
@@ -227,15 +227,24 @@ public function header()
 
         header('Content-type: ' . Utils::getMimeByExtension($format, 'text/html'));
 
+        $cache_control = $page->cacheControl();
+
         // Calculate Expires Headers if set to > 0
         $expires = $page->expires();
 
         if ($expires > 0) {
             $expires_date = gmdate('D, d M Y H:i:s', time() + $expires) . ' GMT';
-            header('Cache-Control: max-age=' . $expires);
+            if (!$cache_control) {
+                header('Cache-Control: max-age=' . $expires);
+            }
             header('Expires: ' . $expires_date);
         }
 
+        // Set cache-control header
+        if ($cache_control) {
+            header('Cache-Control: ' . strtolower($cache_control));
+        }
+
         // Set the last modified time
         if ($page->lastModified()) {
             $last_modified_date = gmdate('D, d M Y H:i:s', $page->modified()) . ' GMT';
diff --git a/system/src/Grav/Common/Page/Page.php b/system/src/Grav/Common/Page/Page.php
index 164ec8792..2395697ba 100644
--- a/system/src/Grav/Common/Page/Page.php
+++ b/system/src/Grav/Common/Page/Page.php
@@ -42,6 +42,7 @@ class Page
     protected $parent;
     protected $template;
     protected $expires;
+    protected $cache_control;
     protected $visible;
     protected $published;
     protected $publish_date;
@@ -429,6 +430,9 @@ public function header($var = null)
             if (isset($this->header->expires)) {
                 $this->expires = intval($this->header->expires);
             }
+            if (isset($this->header->cache_control)) {
+                $this->cache_control = $this->header->cache_control;
+            }
             if (isset($this->header->etag)) {
                 $this->etag = (bool)$this->header->etag;
             }
@@ -1250,6 +1254,22 @@ public function expires($var = null)
         return !isset($this->expires) ? Grav::instance()['config']->get('system.pages.expires') : $this->expires;
     }
 
+    /**
+     * Gets and sets the cache-control property.  If not set it will return the default value (null)
+     * https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Cache-Control for more details on valid options
+     *
+     * @param null $var
+     * @return null
+     */
+    public function cacheControl($var = null)
+    {
+        if ($var !== null) {
+            $this->cache_control = $var;
+        }
+
+        return !isset($this->cache_control) ? Grav::instance()['config']->get('system.pages.cache_control') : $this->cache_control;
+    }
+
     /**
      * Gets and sets the title for this Page.  If no title is set, it will use the slug() to get a name
      *