Index: rest_server.module
===================================================================
RCS file: /cvs/drupal-contrib/contributions/modules/rest_server/Attic/rest_server.module,v
retrieving revision 1.1.2.1.2.2
diff -u -r1.1.2.1.2.2 rest_server.module
--- rest_server.module	12 Mar 2009 17:21:07 -0000	1.1.2.1.2.2
+++ rest_server.module	27 Aug 2009 01:13:59 -0000
@@ -74,8 +74,21 @@
     $result = rest_server_server_error($e->getMessage());
   }
 
-  drupal_set_header('Content-type: text/xml');
-  print rest_server_to_xml($result);
+  // Default to xml.
+  if (!isset($request['format'])) {
+    $request['format'] = 'xml';
+  }
+
+  switch ($request['format']) {
+    case 'json':
+      drupal_set_header('Content-type: application/json');
+      print rest_server_to_js($result);
+      break;
+    case 'xml':
+      drupal_set_header('Content-type: text/xml');
+      print rest_server_to_xml($result);
+      break;
+  }
 }
 
 /**
@@ -92,6 +105,24 @@
 }
 
 /**
+ * Convert data array to JSON representation.
+ *
+ * This function was copied from Drupal 7 code, and make use of PHP 5 JSON
+ * function. It makes sense to require PHP 5 here for performance since the XML
+ * encoder already requires PHP 5+ SimpleXML objects. 
+ *
+ * @param $var
+ *   Array or object with data to convert.
+ *
+ * @return
+ *   String, JSON representation.
+ */
+function rest_server_to_js($var) {
+  // json_encode() does not escape <, > and &, so we do it with str_replace().
+  return str_replace(array("<", ">", "&"), array('\x3c', '\x3e', '\x26'), json_encode($var));
+}
+
+/**
  * Convert data array to xml representation.
  *
  * @param $data