public async Task Setup(string endpoint, Version version)
{
_endpoint = endpoint;
// Changes which affect minor version require a new projection, ignore revision and build numbers
_version = new Version(version.Major, version.Minor);
await _consumer.EnableProjection("$by_category").ConfigureAwait(false);
_cancelation = new CancellationTokenSource();
var discoveredEvents =
_messaging.GetHandledTypes().Where(x => typeof(IEvent).IsAssignableFrom(x)).OrderBy(x => x.FullName).ToList();
if (!discoveredEvents.Any())
{
Logger.Warn($"Event consuming is enabled but we did not detect any IEvent handlers");
return;
}
// Dont use - we dont need category projection projecting our projection
var stream = $"{_endpoint}.{_version}".Replace("-", "");
// Link all events we are subscribing to to a stream
var functions =
discoveredEvents
.Select(
eventType => $"'{_registrar.GetVersionedName(eventType)}': processEvent")
.Aggregate((cur, next) => $"{cur},\n{next}");
// endpoint will get all events regardless of version of info
// it will be up to them to handle upgrades
if (_allEvents)
{
functions = "$any: processEvent";
}
// Don't tab this '@' will create tabs in projection definition
var definition = @"
function processEvent(s,e) {{
linkTo('{1}', e);
}}
options({{
reorderEvents: false,
processingLag: 0
}})
fromStreams([{0}]).
when({{
{2}
}});";
// Todo: replace with `fromCategories([])` when available
var appDefinition = string.Format(definition, $"'$ce-{StreamTypes.Domain}','$ce-{StreamTypes.OOB}'", stream, functions);
await _consumer.CreateProjection($"{stream}.app.projection", appDefinition).ConfigureAwait(false);
}
