/// <summary>
/// Initializes a new instance.
/// </summary>
/// <param name="name"></param>
/// <param name="filterExpression"></param>
/// <param name="itemsExpression"></param>
/// <param name="requestIdExpression"></param>
/// <param name="accessor"></param>
/// <param name="settings"></param>
public StateMachineMultiRequest(
string name,
Expression <Func <TInstance, Guid, bool> > filterExpression,
Expression <Func <TInstance, IEnumerable <TState> > > itemsExpression,
Expression <Func <TState, Guid?> > requestIdExpression,
IMultiRequestStateAccessor <TInstance, TState, TRequest, TResponse> accessor,
MultiRequestSettings settings)
{
this.name = name ?? throw new ArgumentNullException(nameof(name));
this.filterFunc = filterExpression?.Compile() ?? throw new ArgumentNullException(nameof(filterExpression));
this.itemsFunc = itemsExpression?.Compile() ?? throw new ArgumentNullException(nameof(itemsExpression));
this.requestIdFunc = requestIdExpression?.Compile() ?? throw new ArgumentNullException(nameof(requestIdExpression));
this.accessor = accessor ?? throw new ArgumentNullException(nameof(accessor));
this.settings = settings;
}
/// <summary>
/// Declares a request that is sent by the state machine to a service, and the associated response, fault, and
/// timeout handling. The property is initialized with the fully built Request. The request must be declared
/// before it is used in the state/event declaration statements.
/// </summary>
/// <typeparam name="TState"></typeparam>
/// <typeparam name="TRequest"></typeparam>
/// <typeparam name="TResponse"></typeparam>
/// <param name="propertyExpression"></param>
/// <param name="itemsExpression"></param>
/// <param name="requestIdExpression"></param>
/// <param name="accessor"></param>
/// <param name="settings"></param>
protected void MultiRequest <TState, TRequest, TResponse>(
Expression <Func <MultiRequest <TInstance, TState, TRequest, TResponse> > > propertyExpression,
Expression <Func <TInstance, IEnumerable <TState> > > itemsExpression,
Expression <Func <TState, Guid?> > requestIdExpression,
IMultiRequestStateAccessor <TInstance, TState, TRequest, TResponse> accessor,
MultiRequestSettings settings = null)
where TRequest : class
where TResponse : class
{
// default settings
if (settings == null)
{
settings = new StateMachineMultiRequestConfigurator <TRequest>();
}
var property = propertyExpression.GetPropertyInfo();
// parameters reused within expressions
var instanceParameter = Expression.Parameter(typeof(TInstance), "instance");
var itemParameter = Expression.Parameter(typeof(TState), "item");
var requestIdParameter = Expression.Parameter(typeof(Guid), "requestId");
// filters an instance to that which contains the request
var filterExpression = Expression.Lambda <Func <TInstance, Guid, bool> >(
Expression.Call(
typeof(Enumerable),
nameof(Enumerable.Any),
new[] { typeof(TState) },
itemsExpression.Body.Replace(itemsExpression.Parameters[0], instanceParameter),
Expression.Lambda <Func <TState, bool> >(
Expression.Equal(
Expression.Convert(requestIdExpression.Body.Replace(requestIdExpression.Parameters[0], itemParameter), typeof(Guid?)),
Expression.Convert(requestIdParameter, typeof(Guid?))),
itemParameter)),
instanceParameter,
requestIdParameter);
var request = new StateMachineMultiRequest <TInstance, TState, TRequest, TResponse>(property.Name, filterExpression, itemsExpression, requestIdExpression, accessor, settings);
InitializeMultiRequest(this, property, request);
Event(propertyExpression, x => x.Finished);
// filters instances for the Completed event
var completedContextParameter = Expression.Parameter(typeof(ConsumeContext <TResponse>), "context");
var completedExpression = Expression.Lambda <Func <TInstance, ConsumeContext <TResponse>, bool> >(
Expression.Call(
typeof(Enumerable),
nameof(Enumerable.Any),
new[] { typeof(TState) },
itemsExpression.Body.Replace(itemsExpression.Parameters[0], instanceParameter),
Expression.Lambda <Func <TState, bool> >(
Expression.Equal(
requestIdExpression.Body.Replace(requestIdExpression.Parameters[0], itemParameter),
Expression.Property(completedContextParameter, typeof(MessageContext), nameof(MessageContext.RequestId))),
itemParameter)),
instanceParameter,
completedContextParameter);
// filters instances for the Faulted event
var faultedContextParameter = Expression.Parameter(typeof(ConsumeContext <Fault <TRequest> >), "context");
var faultedExpression = Expression.Lambda <Func <TInstance, ConsumeContext <Fault <TRequest> >, bool> >(
Expression.Call(
typeof(Enumerable),
nameof(Enumerable.Any),
new[] { typeof(TState) },
itemsExpression.Body.Replace(itemsExpression.Parameters[0], instanceParameter),
Expression.Lambda <Func <TState, bool> >(
Expression.Equal(
requestIdExpression.Body.Replace(requestIdExpression.Parameters[0], itemParameter),
Expression.Property(faultedContextParameter, typeof(MessageContext), nameof(MessageContext.RequestId))),
itemParameter)),
instanceParameter,
faultedContextParameter);
// filters instances for the TimeoutExpired event
var timeoutExpiredContextParameter = Expression.Parameter(typeof(ConsumeContext <RequestTimeoutExpired <TRequest> >), "context");
var timeoutExpiredExpression = Expression.Lambda <Func <TInstance, ConsumeContext <RequestTimeoutExpired <TRequest> >, bool> >(
Expression.Call(
typeof(Enumerable),
nameof(Enumerable.Any),
new[] { typeof(TState) },
itemsExpression.Body.Replace(itemsExpression.Parameters[0], instanceParameter),
Expression.Lambda <Func <TState, bool> >(
Expression.Equal(
requestIdExpression.Body.Replace(requestIdExpression.Parameters[0], itemParameter),
Expression.Convert(
Expression.Property(
Expression.Property(timeoutExpiredContextParameter, typeof(ConsumeContext <RequestTimeoutExpired <TRequest> >), nameof(ConsumeContext <RequestTimeoutExpired <TRequest> > .Message)),
typeof(RequestTimeoutExpired <TRequest>),
nameof(RequestTimeoutExpired <TRequest> .RequestId)),
typeof(Guid?))),
itemParameter)),
instanceParameter,
timeoutExpiredContextParameter);
Event(propertyExpression, x => x.Completed, x => x.CorrelateBy(completedExpression));
Event(propertyExpression, x => x.Faulted, x => x.CorrelateBy(faultedExpression));
Event(propertyExpression, x => x.TimeoutExpired, x => x.CorrelateBy(timeoutExpiredExpression));
Event(propertyExpression, x => x.FinishedSignal, x => x.CorrelateById(m => (Guid)m.CorrelationId));
State(propertyExpression, x => x.Pending);
DuringAny(
When(request.Completed, request.CompletedEventFilter)
.Add(new MultiRequestItemCompletedActivity <TInstance, TState, TRequest, TResponse>(request))
.Add(new MultiRequestItemFinishedActivity <TInstance, TState, TRequest, TResponse>(request))
.Add(new MultiRequestCancelItemTimeoutActivity <TInstance, TState, TRequest, TResponse>(request)),
When(request.Faulted, request.FaultedEventFilter)
.Add(new MultiRequestItemFaultedActivity <TInstance, TState, TRequest, TResponse>(request))
.Add(new MultiRequestItemFinishedActivity <TInstance, TState, TRequest, TResponse>(request))
.Add(new MultiRequestCancelItemTimeoutActivity <TInstance, TState, TRequest, TResponse>(request)),
When(request.TimeoutExpired, request.RequestTimeoutExpiredEventFilter)
.Add(new MultiRequestItemTimeoutExpiredActivity <TInstance, TState, TRequest, TResponse>(request))
.Add(new MultiRequestItemFinishedActivity <TInstance, TState, TRequest, TResponse>(request))
.Add(new MultiRequestCancelItemTimeoutActivity <TInstance, TState, TRequest, TResponse>(request)),
When(request.FinishedSignal, request.FinishedSignalEventFilter)
.Add(new MultiRequestFinishedActivity <TInstance, TState, TRequest, TResponse>(request)));
}