// Register a new observable
// Returns null if it failed (due to RTD array-caller first call)
static object RegisterObservable(AsyncCallInfo callInfo, IExcelObservable observable)
{
// Check it's not registered already
Debug.Assert(!_asyncCallIds.ContainsKey(callInfo));
// Set up ObservableState and keep track of things
// Caller might be null if not from worksheet
ExcelReference caller = XlCall.Excel(XlCall.xlfCaller) as ExcelReference;
Guid id = Guid.NewGuid();
Debug.Print("AsyncObservableImpl.RegisterObservable - Id: {0}", id);
_asyncCallIds[callInfo] = id;
AsyncObservableState state = new AsyncObservableState(id, callInfo, caller, observable);
_observableStates[id] = state;
// Will spin up RTD server and topic if required, causing us to be called again...
object value;
if (!state.TryGetValue(out value))
{
Debug.Print("AsyncObservableImpl.RegisterObservable (GetValue Error) - Remove Id: {0}", id);
// Problem case - array-caller with RTD call that failed.
// Clean up state and return null - we'll be called again later and everything will be better.
_observableStates.Remove(id);
_asyncCallIds.Remove(callInfo);
return(null);
}
return(value);
}
// This is the most general RTD registration
// This should not be called from a ThreadSafe function. Checked in the callers.
public static object ProcessObservable(string functionName, object parameters, ExcelObservableSource getObservable)
{
if (!SynchronizationManager.IsInstalled)
{
throw new InvalidOperationException("ExcelAsyncUtil has not been initialized. This is an unexpected error.");
}
if (!ExcelDnaUtil.IsMainThread)
{
throw new InvalidOperationException("ExcelAsyncUtil.Run / ExcelAsyncUtil.Observe may not be called from a ThreadSafe function.");
}
// CONSIDER: Why not same problems with all RTD servers?
AsyncCallInfo callInfo = new AsyncCallInfo(functionName, parameters);
// Shortcut if already registered
Guid id;
if (_asyncCallIds.TryGetValue(callInfo, out id))
{
// Already registered.
Debug.Print("AsyncObservableImpl GetValueIfRegistered - Found Id: {0}", id);
AsyncObservableState state = _observableStates[id];
object value;
// The TryGetValue call here is a big deal - it eventually calls Excel's RTD function
// (or not, it the observable is complete).
// The return value of TryGetValue indicates the special array-call where RTD fails, which we ignore here.
bool unused = state.TryGetValue(out value);
return(value);
}
// Not registered before - actually register as a new Observable
IExcelObservable observable = getObservable();
return(RegisterObservable(callInfo, observable));
}
internal static void DisconnectObserver(Guid id)
{
AsyncObservableState state = _observableStates[id];
state.Unsubscribe();
_observableStates.Remove(id);
_asyncCallIds.Remove(state.GetCallInfo());
}
internal static void ConnectObserver(Guid id, ExcelRtdObserver rtdObserver)
{
// TODO: Checking...(huh?)
AsyncObservableState state = _observableStates[id];
// Start the work for this AsyncCallInfo, and subscribe the topic to the result
state.Subscribe(rtdObserver);
}
static bool GetValueIfRegistered(AsyncCallInfo callInfo, out object value)
{
Guid id;
if (_asyncCallIds.TryGetValue(callInfo, out id))
{
// Already registered.
AsyncObservableState state = _observableStates[id];
value = state.GetValue();
return(true);
}
value = null;
return(false);
}
// Register a new observable
static object RegisterObservable(AsyncCallInfo callInfo, IExcelObservable observable)
{
// Check it's not registered already
Debug.Assert(!_asyncCallIds.ContainsKey(callInfo));
// Set up a new Id and ObservableState and keep track of things
Guid id = Guid.NewGuid();
_asyncCallIds[callInfo] = id;
AsyncObservableState state = new AsyncObservableState(id, callInfo, observable);
_observableStates[id] = state;
// Will spin up RTD server and topic if required, causing us to be called again...
return(state.GetValue());
}
// Register a new observable
static object RegisterObservable(AsyncCallInfo callInfo, IExcelObservable observable)
{
// Check it's not registered already
Debug.Assert(!_asyncCallIds.ContainsKey(callInfo));
// Set up ObservableState and keep track of things
// Caller might be null if not from worksheet
ExcelReference caller = XlCall.Excel(XlCall.xlfCaller) as ExcelReference;
Guid id = Guid.NewGuid();
_asyncCallIds[callInfo] = id;
AsyncObservableState state = new AsyncObservableState(id, callInfo, caller, observable);
_observableStates[id] = state;
// Will spin up RTD server and topic if required, causing us to be called again...
return(state.GetValue());
}
// Register a new observable
static object RegisterObservable(AsyncCallInfo callInfo, IExcelObservable observable)
{
// Check it's not registered already
Debug.Assert(!_asyncCallIds.ContainsKey(callInfo));
// Set up a new Id and ObservableState and keep track of things
Guid id = Guid.NewGuid();
_asyncCallIds[callInfo] = id;
AsyncObservableState state = new AsyncObservableState(id, callInfo, observable);
_observableStates[id] = state;
// Will spin up RTD server and topic if required, causing us to be called again...
return state.GetValue();
}
