public static async Task <HttpResponseMessage> RunProjectionForQueryCommand(
[HttpTrigger(AuthorizationLevel.Function, "POST", Route = @"CQRS/RunProjectionForQuery/{queryIdentifier}")] HttpRequestMessage req,
string queryIdentifier
)
{
#region Tracing telemetry
Activity.Current.AddTag("Query Identifier", queryIdentifier);
#endregion
// 1 - Read the ProjectionRequestData from the body
ProjectionRequestedEventGridEventData data = await req.Content.ReadAsAsync <ProjectionRequestedEventGridEventData>();
if (data != null)
{
if (string.IsNullOrWhiteSpace(data.InstanceKey))
{
data.InstanceKey = queryIdentifier;
}
await RunProjectionForQuery(data);
return(req.CreateResponse(System.Net.HttpStatusCode.OK));
}
else
{
// The projection cannot be run if there is no body supplied
return(req.CreateResponse(System.Net.HttpStatusCode.BadRequest,
"The projection details were not correctly specified in the request body"));
}
}
public static async Task OnQueryProjectionHandler(
[EventGridTrigger] EventGridEvent eventGridEvent)
{
if (eventGridEvent != null)
{
// Get the data from the event that describes what projection is requested
ProjectionRequestedEventGridEventData projectionRequestData = eventGridEvent.Data.ToObjectFromJson <ProjectionRequestedEventGridEventData>();
await ProjectionHandlerFunctions.RunProjectionForQuery(projectionRequestData);
}
}
/// <summary>
/// A projection has been requested in processing a command.
/// This function will run it and attach the result back to the command
/// event stream when complete.
/// </summary>
public static async Task RunProjectionForCommand(ProjectionRequestedEventGridEventData projectionRequestData)
{
if (projectionRequestData != null)
{
// Process the projection
Projection projection = new Projection(
new ProjectionAttribute(
projectionRequestData.ProjectionRequest.ProjectionDomainName,
projectionRequestData.ProjectionRequest.ProjectionEntityTypeName,
projectionRequestData.ProjectionRequest.ProjectionInstanceKey,
projectionRequestData.ProjectionRequest.ProjectionTypeName
));
if (_projectionMap == null)
{
_projectionMap = ProjectionMaps.CreateDefaultProjectionMaps();
}
IProjection projectionToRun = _projectionMap.CreateProjectionClass(projectionRequestData.ProjectionRequest.ProjectionTypeName);
IProjection completedProjection = null;
if (projectionToRun != null)
{
completedProjection = await projection.Process(projectionToRun,
projectionRequestData.ProjectionRequest.AsOfDate);
}
// Attach the results back to the query event stream
Command cmdSource = new Command(projectionRequestData.DomainName,
projectionRequestData.EntityTypeName,
projectionRequestData.InstanceKey);
if (cmdSource != null)
{
int CurrentSequenceNumber = 0;
if (completedProjection != null)
{
CurrentSequenceNumber = completedProjection.CurrentSequenceNumber;
}
await cmdSource.PostProjectionResponse(projectionRequestData.ProjectionRequest.ProjectionDomainName,
projectionRequestData.ProjectionRequest.ProjectionEntityTypeName,
projectionRequestData.ProjectionRequest.ProjectionInstanceKey,
projectionRequestData.ProjectionRequest.ProjectionTypeName,
projectionRequestData.ProjectionRequest.AsOfDate,
projectionRequestData.ProjectionRequest.CorrelationIdentifier,
CurrentSequenceNumber,
completedProjection);
}
}
}
