Method InvokeCallbacks

Core/ConnectionSML/src/sml_Connection.cpp:407–475

* @brief Invoke the list of callbacks matching the doctype of the incoming message. * * @param pIncomingMsg The SML message that should be passed to the callbacks. * @returns The response message (or NULL if there is no response from any callback). *************************************************************/

* @returns The response message (or NULL if there is no response from any callback).
*************************************************************/
ElementXML* Connection::InvokeCallbacks(ElementXML* pIncomingMsg)
{
    ClearError() ;
    
    MessageSML* pIncomingSML = (MessageSML*)pIncomingMsg ; // MessageSML is a soarxml::ElementXML, not sml::ElementXML
    
    // Check that we were passed a valid message.
    if (pIncomingMsg == NULL)
    {
        SetError(Error::kInvalidArgument) ;
        return NULL ;
    }
    
    // Retrieve the type of this message
    char const* pType = pIncomingSML->GetDocType() ;
    
    // Check that this message has a valid doc type (all valid SML do)
    if (pType == NULL)
    {
        SetError(Error::kNoDocType) ;
        return NULL ;
    }
    
    // Decide if this message is a "call" which requires a "response"
    bool isIncomingCall = pIncomingSML->IsCall() ;
    
    // See if we have a list of callbacks for this type
    CallbackList* pList = GetCallbackList(pType) ;
    
    // Nobody was interested in this type of message, so we're done.
    if (pList == NULL)
    {
        return NULL ;
    }
    
    CallbackListIter iter = pList->begin() ;
    
    // Walk the list of callbacks in turn until we reach
    // the end or one returns a message.
    while (iter != pList->end())
    {
        Callback* pCallback = *iter ;
        iter++ ;
        
        ElementXML* pResponse = pCallback->Invoke(pIncomingMsg) ;
        
        if (pResponse != NULL)
        {
            if (isIncomingCall)
            {
                return pResponse ;
            }
            
            // This callback was not for a call and should not return a result.
            // Delete the result and ignore it.
            pResponse->ReleaseRefOnHandle() ;
            pResponse = NULL ;
        }