Added a configuration option to set a default lifetime on cache saves

system/config/system.yaml

@@ -27,6 +27,7 @@ cache:
     method: file                       # Method to check for updates in pages: file|folder|none
   driver: auto                         # One of: auto|file|apc|xcache|memcache|wincache
   prefix: 'g'                          # Cache prefix string (prevents cache conflicts)
+  lifetime: 86400                      # Lifetime of cached data in seconds (0 = infinite)
 
 twig:
   cache: true                          # Set to true to enable twig caching

system/src/Grav/Common/Cache.php

@@ -154,6 +154,10 @@ class Cache extends Getters
     public function save($id, $data, $lifetime = null)
     {
         if ($this->enabled) {
+
+            if ($lifetime == null) {
+                $lifetime = $this->config->get('system.cache.lifetime') ?: null;
+            }
             $this->driver->save($id, $data, $lifetime);
         }
     }