ActionController: helper method for JSON errors

library/Director/Web/Controller/ActionController.php

@@ -166,6 +166,27 @@ abstract class ActionController extends Controller
         $this->prepareTable($name)->render('list/table', null, true);
     }
 
+    // TODO: just return json_last_error_msg() for PHP >= 5.5.0
+    protected function getLastJsonError()
+    {
+        switch (json_last_error()) {
+            case JSON_ERROR_DEPTH:
+                return 'The maximum stack depth has been exceeded';
+            case JSON_ERROR_CTRL_CHAR:
+                return 'Control character error, possibly incorrectly encoded';
+            case JSON_ERROR_STATE_MISMATCH:
+                return 'Invalid or malformed JSON';
+            case JSON_ERROR_SYNTAX:
+                return 'Syntax error';
+            case JSON_ERROR_UTF8:
+                return 'Malformed UTF-8 characters, possibly incorrectly encoded';
+            default:
+                return 'An error occured when parsing a JSON string';
+        }
+
+        return $this;
+    }
+
     protected function api($endpointName = null)
     {
         if ($this->api === null) {