order_static add if nil

app/models/order_static.rb

@@ -26,10 +26,15 @@ class OrderStatic < ActiveRecord::Base
   end
 
   def begin_date_fomat
-    return self.begin_date.strftime
+
+    if self.begin_date !=nil?
+      return self.begin_date.strftime
+    end
   end
   def end_date_fomat
-    return self.end_date.strftime
+    if self.end_date !=nil?
+      return self.end_date.strftime
+    end
   end
 
   STATUS_ENUM = [["处理中,已完成,待收货",""],["未支付","unpay"],["已关闭","closed"],["待确认","unconfirmed"],["处理中","processing"],["已完成","complete"],["待收货","dispatch"],["已退款","refunded"]]