tweeper.php: make jsonToXml() a static method

diff --git a/tweeper.php b/tweeper.php
index 817452b..f475856 100644 (file)
--- a/tweeper.php
+++ b/tweeper.php
@@ -221,7 +221,7 @@ class Tweeper {
   /**
    * Convert json to xml.
    */
-  private function jsonToXml($json, $root_node_name) {
+  private static function jsonToXml($json, $root_node_name) {
     // Apparently the ObjectNormalizer used afterwards is not able to handle
     // the stdClass object created by json_decode() with the default setting
     // $assoc = false; so use $assoc = true.
@@ -261,7 +261,7 @@ class Tweeper {
       return NULL;
     }
 
-    return $this->jsonToXml($matches[1], 'instagram');
+    return Tweeper::jsonToXml($matches[1], 'instagram');
   }
 
   /**