diff --git a/src/ESPUIclient.cpp b/src/ESPUIclient.cpp
index 9b7d561..62644a8 100644
--- a/src/ESPUIclient.cpp
+++ b/src/ESPUIclient.cpp
@@ -307,7 +307,7 @@ uint32_t ESPUIclient::prepareJSONChunk(uint16_t startindex,
 
             JsonObject item = items.createNestedObject();
             elementcount++;
-            control->MarshalControl(item, InUpdateMode);
+            control->MarshalControl(item, InUpdateMode, ClientTransferContext);
             
             if (rootDoc.overflowed())
             {
@@ -315,6 +315,7 @@ uint32_t ESPUIclient::prepareJSONChunk(uint16_t startindex,
                 if (1 == elementcount)
                 {
                     Serial.println(String(F("ERROR: prepareJSONChunk: Control ")) + String(control->id) + F(" is too large to be sent to the browser."));
+                    // Serial.println(String(F("ERROR: prepareJSONChunk: value: ")) + control->value);
                     rootDoc.clear();
                     item = items.createNestedObject();
                     control->MarshalErrorMessage(item);
@@ -330,7 +331,6 @@ uint32_t ESPUIclient::prepareJSONChunk(uint16_t startindex,
                 }
                 // exit the loop
                 control = nullptr;
-
             }
             else
             {
diff --git a/src/ESPUIclient.h b/src/ESPUIclient.h
index 5a34699..6a67fda 100644
--- a/src/ESPUIclient.h
+++ b/src/ESPUIclient.h
@@ -17,6 +17,12 @@ public:
         ReloadNeeded    = 3,
     };
 
+    struct ClientTransferContext_t
+    {
+        void       *control = nullptr;
+        uint16_t    Offset = 0;
+    };
+
 protected:
     // bool HasBeenNotified      = false;  // Set when a notification has been sent and we are waiting for a reply
     // bool DelayedNotification  = false;  // set if a delayed notification is needed
@@ -39,7 +45,8 @@ protected:
     fsm_EspuiClient_state* pCurrentFsmState = &fsm_EspuiClient_state_Idle_imp;
 
     time_t      EspuiClientEndTime = 0;
-
+    ClientTransferContext_t ClientTransferContext;
+    
     // bool        NeedsNotification() { return pCurrentFsmState != &fsm_EspuiClient_state_Idle_imp; }
 
     bool        CanSend();