Cancel data change

Server/mods/deathmatch/logic/CElement.cpp

@@ -709,22 +709,24 @@ bool CElement::GetCustomDataBool(const CStringName& name, bool& bOut, bool bInhe
     return false;
 }
 
-void CElement::SetCustomData(const CStringName& name, const CLuaArgument& Variable, ESyncType syncType, CPlayer* pClient, bool bTriggerEvent)
+bool CElement::SetCustomData(const CStringName& name, const CLuaArgument& Variable, ESyncType syncType, CPlayer* pClient, bool bTriggerEvent)
 {
     assert(name);
     if (name->length() > MAX_CUSTOMDATA_NAME_LENGTH)
     {
         // Don't allow it to be set if the name is too long
         CLogger::ErrorPrintf("Custom data name too long (%s)\n", *SStringX(name.ToCString()).Left(MAX_CUSTOMDATA_NAME_LENGTH + 1));
-        return;
+        return false;
     }
 
-    // Grab the old variable
+    // Grab the old variable and sync type
     CLuaArgument       oldVariable;
+    ESyncType          oldSyncType = ESyncType::LOCAL;
     const SCustomData* pData = m_CustomData.Get(name);
     if (pData)
     {
         oldVariable = pData->Variable;
+        oldSyncType = pData->syncType;
     }
 
     // Set the new data
@@ -737,18 +739,27 @@ void CElement::SetCustomData(const CStringName& name, const CLuaArgument& Variab
         Arguments.PushString(name);
         Arguments.PushArgument(oldVariable);
         Arguments.PushArgument(Variable);
-        CallEvent("onElementDataChange", Arguments, pClient);
+        if (!CallEvent("onElementDataChange", Arguments, pClient))
+        {
+            // Event was cancelled, restore previous value
+            if (pData)
+                m_CustomData.Set(name, oldVariable, oldSyncType);
+            else
+                m_CustomData.Delete(name);
+            return false;
+        }
     }
+    return true;
 }
 
-void CElement::DeleteCustomData(const CStringName& name)
+bool CElement::DeleteCustomData(const CStringName& name)
 {
     // Grab the old variable
     SCustomData* pData = m_CustomData.Get(name);
     if (pData)
     {
-        CLuaArgument oldVariable;
-        oldVariable = pData->Variable;
+        CLuaArgument oldVariable = pData->Variable;
+        ESyncType    oldSyncType = pData->syncType;
 
         // Delete the custom data
         m_CustomData.Delete(name);
@@ -758,8 +769,15 @@ void CElement::DeleteCustomData(const CStringName& name)
         Arguments.PushString(name);
         Arguments.PushArgument(oldVariable);
         Arguments.PushArgument(CLuaArgument());            // Use nil as the new value to indicate the data has been removed
-        CallEvent("onElementDataChange", Arguments);
+        if (!CallEvent("onElementDataChange", Arguments))
+        {
+            // Event was cancelled, restore previous value
+            m_CustomData.Set(name, oldVariable, oldSyncType);
+            return false;
+        }
+        return true;
     }
+    return false;
 }
 
 // Used to send the root element data when a player joins

Server/mods/deathmatch/logic/CElement.h

@@ -145,9 +145,9 @@ class CElement
     bool           GetCustomDataInt(const CStringName& name, int& iOut, bool bInheritData);
     bool           GetCustomDataFloat(const CStringName& name, float& fOut, bool bInheritData);
     bool           GetCustomDataBool(const CStringName& name, bool& bOut, bool bInheritData);
-    void           SetCustomData(const CStringName& name, const CLuaArgument& Variable, ESyncType syncType = ESyncType::BROADCAST, CPlayer* pClient = NULL,
+    bool           SetCustomData(const CStringName& name, const CLuaArgument& Variable, ESyncType syncType = ESyncType::BROADCAST, CPlayer* pClient = NULL,
                                  bool bTriggerEvent = true);
-    void           DeleteCustomData(const CStringName& name);
+    bool           DeleteCustomData(const CStringName& name);
     void           SendAllCustomData(CPlayer* pPlayer);
 
     CXMLNode* OutputToXML(CXMLNode* pNode);

Server/mods/deathmatch/logic/CGame.cpp

@@ -2738,25 +2738,45 @@ void CGame::Packet_CustomData(CCustomDataPacket& Packet)
                 return;
             }
 
-            if (lastSyncType != ESyncType::LOCAL)
+            if (pElement->SetCustomData(szName, Value, lastSyncType, pSourcePlayer))
             {
-                // Tell our clients to update their data. Send to everyone but the one we got this packet from.
+                if (lastSyncType != ESyncType::LOCAL)
+                {
+                    // Tell our clients to update their data. Send to everyone but the one we got this packet from.
+                    unsigned short usNameLength = static_cast<unsigned short>(strlen(szName));
+                    CBitStream     BitStream;
+                    BitStream.pBitStream->WriteCompressed(usNameLength);
+                    BitStream.pBitStream->Write(szName, usNameLength);
+                    Value.WriteToBitStream(*BitStream.pBitStream);
+                    if (lastSyncType == ESyncType::BROADCAST)
+                        m_pPlayerManager->BroadcastOnlyJoined(CElementRPCPacket(pElement, SET_ELEMENT_DATA, *BitStream.pBitStream), pSourcePlayer);
+                    else
+                        m_pPlayerManager->BroadcastOnlySubscribed(CElementRPCPacket(pElement, SET_ELEMENT_DATA, *BitStream.pBitStream), pElement, szName,
+                                                                  pSourcePlayer);
+
+                    CPerfStatEventPacketUsage::GetSingleton()->UpdateElementDataUsageRelayed(szName, m_pPlayerManager->Count(),
+                                                                                             BitStream.pBitStream->GetNumberOfBytesUsed());
+                }
+            }
+            else
+            {
+                // Event was cancelled; sync the authoritative value back to the source player
                 unsigned short usNameLength = static_cast<unsigned short>(strlen(szName));
                 CBitStream     BitStream;
                 BitStream.pBitStream->WriteCompressed(usNameLength);
                 BitStream.pBitStream->Write(szName, usNameLength);
-                Value.WriteToBitStream(*BitStream.pBitStream);
-                if (lastSyncType == ESyncType::BROADCAST)
-                    m_pPlayerManager->BroadcastOnlyJoined(CElementRPCPacket(pElement, SET_ELEMENT_DATA, *BitStream.pBitStream), pSourcePlayer);
-                else
-                    m_pPlayerManager->BroadcastOnlySubscribed(CElementRPCPacket(pElement, SET_ELEMENT_DATA, *BitStream.pBitStream), pElement, szName,
-                                                              pSourcePlayer);
 
-                CPerfStatEventPacketUsage::GetSingleton()->UpdateElementDataUsageRelayed(szName, m_pPlayerManager->Count(),
-                                                                                         BitStream.pBitStream->GetNumberOfBytesUsed());
+                if (CLuaArgument* pServerValue = pElement->GetCustomData(szName, false))
+                {
+                    pServerValue->WriteToBitStream(*BitStream.pBitStream);
+                    pSourcePlayer->Send(CElementRPCPacket(pElement, SET_ELEMENT_DATA, *BitStream.pBitStream));
+                }
+                else
+                {
+                    BitStream.pBitStream->WriteBit(false);
+                    pSourcePlayer->Send(CElementRPCPacket(pElement, REMOVE_ELEMENT_DATA, *BitStream.pBitStream));
+                }
             }
-
-            pElement->SetCustomData(szName, Value, lastSyncType, pSourcePlayer);
         }
     }
 }

Server/mods/deathmatch/logic/CStaticFunctionDefinitions.cpp

@@ -1017,6 +1017,9 @@ bool CStaticFunctionDefinitions::SetElementData(CElement* pElement, CStringName
 
     if (!pCurrentVariable || *pCurrentVariable != Variable || lastSyncType != syncType)
     {
+        if (!pElement->SetCustomData(name, Variable, syncType))
+            return false; // The server cancelled the change in onElementDataChange
+
         if (syncType != ESyncType::LOCAL)
         {
             // Tell our clients to update their data
@@ -1037,8 +1040,6 @@ bool CStaticFunctionDefinitions::SetElementData(CElement* pElement, CStringName
         if (lastSyncType == ESyncType::SUBSCRIBE && syncType != ESyncType::SUBSCRIBE)
             m_pPlayerManager->ClearElementData(pElement, name);
 
-        // Set its custom data
-        pElement->SetCustomData(name, Variable, syncType);
         return true;
     }
     return false;
@@ -1053,6 +1054,9 @@ bool CStaticFunctionDefinitions::RemoveElementData(CElement* pElement, CStringNa
     // Check it exists
     if (pElement->GetCustomData(name, false))
     {
+        if (!pElement->DeleteCustomData(name))
+            return false; // The server cancelled the change in onElementDataChange
+
         // Tell our clients to update their data
         unsigned short usNameLength = static_cast<unsigned short>(name->length());
         CBitStream     BitStream;
@@ -1064,8 +1068,6 @@ bool CStaticFunctionDefinitions::RemoveElementData(CElement* pElement, CStringNa
         // Clean up after the data removal
         m_pPlayerManager->ClearElementData(pElement, name);
 
-        // Delete here
-        pElement->DeleteCustomData(name);
         return true;
     }