Fixed default data if response is malformed

app/code/community/Emico/Tweakwise/Model/Bus/Type/Abstract.php

@@ -50,7 +50,7 @@ protected function setDataFromField(SimpleXMLElement $xmlElement, $field, $type,
         $data = $useProvidedAsData ? $xmlElement : $xmlElement->{$field};
 
         if (!is_object($data)) {
-            $this->setData($dataKey, '');
+            $this->setData($dataKey, $this->resolveDefaultValue($count));
 
             return $this;
         }
@@ -76,6 +76,22 @@ protected function setDataFromField(SimpleXMLElement $xmlElement, $field, $type,
         return $this;
     }
 
+    /**
+     * @param $count
+     * @return array|string|null
+     */
+    protected function resolveDefaultValue($count)
+    {
+        switch ($count) {
+            case self::ELEMENT_COUNT_ONE:
+            case self::ELEMENT_COUNT_NONE_OR_ONE:
+                return '';
+            case self::ELEMENT_COUNT_NONE_OR_MORE:
+            case self::ELEMENT_COUNT_ONE_OR_MORE:
+                return [];
+        }
+    }
+
     /**
      * @param SimpleXMLElement $xmlElement
      * @param string $type
@@ -120,4 +136,4 @@ protected function setDataFromAttribute(SimpleXMLElement $element, $attribute, $
             $this->setData($dataKey, $value);
         }
     }
-}
+}