/*************************************************************
* @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).
*************************************************************/
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 ;
}
}
// If this is a call, we must respond
if (isIncomingCall)
SetError(Error::kNoResponseToCall) ;
// Nobody returned a response
return NULL ;
}
