/// <summary>
/// Initializes a new instance of the <see cref="BasicEventStream"/> class.
/// </summary>
/// <param name="dataStream">The data stream.</param>
/// <param name="separator">The separator.</param>
public BasicEventStream(IDataStream dataStream, string separator)
{
_dataStream = dataStream;
_separator = separator;
_contextGenerator = new BasicContextGenerator(_separator);
if (_dataStream.HasNext())
{
_nextEvent = CreateEvent((string)_dataStream.NextToken());
}
}
/// <summary>
/// Returns the next Event object held in this EventStream. Each call to nextEvent advances the EventStream.
/// </summary>
/// <returns>
/// The Event object which is next in this EventStream if there are any events in the stream;
/// otherwise <c>null</c>.
/// </returns>
public override Event Next()
{
LoopForNextEvent();
Event currentEvent = _nextEvent;
if (_dataStream.HasNext())
{
_nextEvent = CreateEvent((string)_dataStream.NextToken());
}
else
{
_nextEvent = null;
}
return currentEvent;
}
private void LoopForNextEvent()
{
while (_nextEvent == null && _dataStream.HasNext())
{
_nextEvent = CreateEvent((string)_dataStream.NextToken());
}
}
private Event CreateEvent(string obs)
{
int lastSeparator = obs.LastIndexOf(_separator);
if (lastSeparator < 0)
{
return null;
}
Event e = new Event(obs.Substring(lastSeparator + 1), _contextGenerator.GetContext(obs.Substring(0, lastSeparator)));
return e;
}