Updates to Sample Code

- Updated UI Presentation on samples
- Fixed Bugs

lib/PayPal/Validation/JsonValidator.php

@@ -14,14 +14,18 @@ class JsonValidator
      * Helper method for validating if string provided is a valid json.
      *
      * @param string $string String representation of Json object
+     * @param bool $silent Flag to not throw \InvalidArgumentException
      * @return bool
      */
-    public static function validate($string)
+    public static function validate($string, $silent = false)
     {
         json_decode($string);
         if (json_last_error() != JSON_ERROR_NONE) {
-            //Throw an Exception for string or array
-            throw new \InvalidArgumentException("Invalid JSON String");
+            if ($silent == false) {
+                //Throw an Exception for string or array
+                throw new \InvalidArgumentException("Invalid JSON String");
+            }
+            return false;
         }
         return true;
     }