/// <summary>
/// Adjusts the contract and behavior of each operation that returns <see cref="System.IObservable{T}"/>.
/// </summary>
/// <param name="contractDescription">The contract description to be modified.</param>
/// <param name="endpoint">The endpoint that exposes the contract.</param>
/// <param name="dispatchRuntime">The dispatch runtime that controls service execution.</param>
public void ApplyDispatchBehavior(ContractDescription contractDescription, ServiceEndpoint endpoint, DispatchRuntime dispatchRuntime)
{
Contract.Assume(contractDescription != null);
foreach (var operation in contractDescription.Operations)
{
Contract.Assume(operation != null);
if (ObservableMethodInvoker.IsObservableMethod(operation.SyncMethod))
{
InitializeObservableOperation(operation, ReturnAsListDefault);
}
}
}
/// <summary>
/// Ensures that the method to which this attribute is applied is synchronous and returns <see cref="System.IObservable{T}"/>.
/// </summary>
/// <param name="operationDescription">The operation being examined. Use for examination only. If the operation
/// description is modified, the results are undefined.</param>
public void Validate(OperationDescription operationDescription)
{
Contract.Assume(operationDescription != null);
if (operationDescription.SyncMethod == null)
{
throw new InvalidOperationException(string.Format(CultureInfo.CurrentCulture, Errors.OperationIsNotSynchronous, operationDescription.Name));
}
if (!ObservableMethodInvoker.IsObservableMethod(operationDescription.SyncMethod))
{
throw new InvalidOperationException(string.Format(CultureInfo.CurrentCulture, Errors.OperationIsNotObservable, operationDescription.Name));
}
}
private static void InitializeObservableOperation(OperationDescription operation, bool returnAsListDefault)
{
Contract.Requires(operation != null);
Contract.Requires(operation.SyncMethod != null);
var hasObservableOperationBehavior = false;
var returnAsList = false;
foreach (var behavior in operation.Behaviors)
{
var observableOperationAttribute = behavior as ObservableOperationAttribute;
if (observableOperationAttribute != null)
{
returnAsList = observableOperationAttribute.ReturnAsList;
hasObservableOperationBehavior = true;
}
}
if (!hasObservableOperationBehavior)
{
operation.Behaviors.Add(
new ObservableOperationAttribute()
{
ReturnAsList = returnAsList = returnAsListDefault
});
}
Contract.Assume(operation.SyncMethod != null);
var dataType = ObservableMethodInvoker.GetObservableDataType(operation.SyncMethod.ReturnType);
var returnType = returnAsList ? Rxx.GeneralReflection.MakeGenericType(typeof(IList <>), dataType) : dataType;
foreach (var message in operation.Messages)
{
Contract.Assume(message != null);
if (message.Direction == MessageDirection.Output)
{
Contract.Assume(message.Body.ReturnValue != null);
message.Body.ReturnValue.Type = returnType;
}
}
}
