private EvaluationDetail <T> Evaluate <T>(string featureKey, User user, LdValue defaultValue, LdValue.Converter <T> converter,
bool checkType, EventFactory eventFactory)
{
T defaultValueOfType = converter.ToType(defaultValue);
if (!Initialized)
{
if (_dataStore.Initialized())
{
_evalLog.Warn("Flag evaluation before client initialized; using last known values from data store");
}
else
{
_evalLog.Warn("Flag evaluation before client initialized; data store unavailable, returning default value");
return(new EvaluationDetail <T>(defaultValueOfType, null,
EvaluationReason.ErrorReason(EvaluationErrorKind.ClientNotReady)));
}
}
FeatureFlag featureFlag = null;
try
{
featureFlag = GetFlag(featureKey);
if (featureFlag == null)
{
_evalLog.Info("Unknown feature flag \"{0}\"; returning default value",
featureKey);
_eventProcessor.RecordEvaluationEvent(eventFactory.NewUnknownFlagEvaluationEvent(
featureKey, user, defaultValue, EvaluationErrorKind.FlagNotFound));
return(new EvaluationDetail <T>(defaultValueOfType, null,
EvaluationReason.ErrorReason(EvaluationErrorKind.FlagNotFound)));
}
if (user == null || user.Key == null)
{
_evalLog.Warn("Null user or null user key when evaluating flag \"{0}\"; returning default value", featureKey);
_eventProcessor.RecordEvaluationEvent(eventFactory.NewDefaultValueEvaluationEvent(
featureFlag, user, defaultValue, EvaluationErrorKind.UserNotSpecified));
return(new EvaluationDetail <T>(defaultValueOfType, null,
EvaluationReason.ErrorReason(EvaluationErrorKind.UserNotSpecified)));
}
Evaluator.EvalResult evalResult = _evaluator.Evaluate(featureFlag, user, eventFactory);
if (!IsOffline())
{
foreach (var prereqEvent in evalResult.PrerequisiteEvents)
{
_eventProcessor.RecordEvaluationEvent(prereqEvent);
}
}
var evalDetail = evalResult.Result;
EvaluationDetail <T> returnDetail;
if (evalDetail.VariationIndex == null)
{
returnDetail = new EvaluationDetail <T>(defaultValueOfType, null, evalDetail.Reason);
evalDetail = new EvaluationDetail <LdValue>(defaultValue, null, evalDetail.Reason);
}
else
{
if (checkType && !defaultValue.IsNull && evalDetail.Value.Type != defaultValue.Type)
{
_evalLog.Error("Expected type {0} but got {1} when evaluating feature flag \"{2}\"; returning default value",
defaultValue.Type,
evalDetail.Value.Type,
featureKey);
_eventProcessor.RecordEvaluationEvent(eventFactory.NewDefaultValueEvaluationEvent(
featureFlag, user, defaultValue, EvaluationErrorKind.WrongType));
return(new EvaluationDetail <T>(defaultValueOfType, null,
EvaluationReason.ErrorReason(EvaluationErrorKind.WrongType)));
}
returnDetail = new EvaluationDetail <T>(converter.ToType(evalDetail.Value),
evalDetail.VariationIndex, evalDetail.Reason);
}
_eventProcessor.RecordEvaluationEvent(eventFactory.NewEvaluationEvent(
featureFlag, user, evalDetail, defaultValue));
return(returnDetail);
}
catch (Exception e)
{
LogHelpers.LogException(_evalLog,
string.Format("Exception when evaluating feature flag \"{0}\"", featureKey),
e);
var reason = EvaluationReason.ErrorReason(EvaluationErrorKind.Exception);
if (featureFlag == null)
{
_eventProcessor.RecordEvaluationEvent(eventFactory.NewUnknownFlagEvaluationEvent(
featureKey, user, defaultValue, EvaluationErrorKind.Exception));
}
else
{
_eventProcessor.RecordEvaluationEvent(eventFactory.NewEvaluationEvent(
featureFlag, user, new EvaluationDetail <LdValue>(defaultValue, null, reason), defaultValue));
}
return(new EvaluationDetail <T>(defaultValueOfType, null, reason));
}
}