/// <summary>
/// Constructs an activity instance suitable for executing a local activity.
/// </summary>
/// <param name="client">The associated client.</param>
/// <param name="invokeInfo">The activity invocation information.</param>
/// <param name="contextId">The activity context ID or <c>null</c> for local activities.</param>
/// <returns>The constructed activity.</returns>
private static ActivityBase Create(CadenceClient client, ActivityInvokeInfo invokeInfo, long?contextId)
{
Covenant.Requires <ArgumentNullException>(client != null);
var activity = (ActivityBase)(invokeInfo.Constructor.Invoke(noArgs));
activity.Initialize(client, invokeInfo.ActivityType, invokeInfo.ActivityMethod, client.DataConverter, contextId);
return(activity);
}
/// <summary>
/// Registers an activity type.
/// </summary>
/// <param name="client">The associated client.</param>
/// <param name="activityType">The activity type.</param>
/// <param name="activityTypeName">The name used to identify the implementation.</param>
/// <returns><c>true</c> if the activity was already registered.</returns>
/// <exception cref="InvalidOperationException">Thrown if a different activity class has already been registered for <paramref name="activityTypeName"/>.</exception>
internal static bool Register(CadenceClient client, Type activityType, string activityTypeName)
{
Covenant.Requires <ArgumentNullException>(client != null);
CadenceHelper.ValidateActivityImplementation(activityType);
activityTypeName = GetActivityTypeKey(client, activityTypeName);
var constructInfo = new ActivityInvokeInfo();
constructInfo.ActivityType = activityType;
constructInfo.Constructor = constructInfo.ActivityType.GetConstructor(noTypeArgs);
if (constructInfo.Constructor == null)
{
throw new ArgumentException($"Activity type [{constructInfo.ActivityType.FullName}] does not have a default constructor.");
}
lock (syncLock)
{
if (nameToInvokeInfo.TryGetValue(activityTypeName, out var existingEntry))
{
if (!object.ReferenceEquals(existingEntry.ActivityType, constructInfo.ActivityType))
{
throw new InvalidOperationException($"Conflicting activity type registration: Activity type [{activityType.FullName}] is already registered for workflow type name [{activityTypeName}].");
}
return(true);
}
else
{
nameToInvokeInfo[activityTypeName] = constructInfo;
return(false);
}
}
}
/// <summary>
/// Returns the <see cref="ActivityInvokeInfo"/> for any activity type and activity type name.
/// </summary>
/// <param name="activityType">The targetr activity type.</param>
/// <param name="activityTypeName">The target activity type name.</param>
/// <returns>The <see cref="ActivityInvokeInfo"/>.</returns>
private static ActivityInvokeInfo GetActivityInvokeInfo(Type activityType, string activityTypeName)
{
Covenant.Requires <ArgumentNullException>(activityType != null);
Covenant.Requires <ArgumentNullException>(!string.IsNullOrEmpty(activityTypeName));
var info = new ActivityInvokeInfo();
// Locate the constructor.
info.Constructor = activityType.GetConstructor(noTypeArgs);
if (info.Constructor == null)
{
throw new ArgumentException($"Activity type [{activityType.FullName}] does not have a default constructor.");
}
// Locate the target method. Note that the activity type name will be
// formatted like:
//
// CLIENT-ID::TYPE-NAME
// or CLIENT-ID::TYPE-NAME::METHOD-NAME
var activityTypeNameParts = activityTypeName.Split(CadenceHelper.ActivityTypeMethodSeparator.ToCharArray(), 3);
var activityMethodName = (string)null;
Covenant.Assert(activityTypeNameParts.Length >= 2);
if (activityTypeNameParts.Length > 2)
{
activityMethodName = activityTypeNameParts[2];
}
if (string.IsNullOrEmpty(activityMethodName))
{
activityMethodName = null;
}
foreach (var method in activityType.GetMethods(BindingFlags.Public | BindingFlags.Instance))
{
var activityMethodAttribute = method.GetCustomAttribute <ActivityMethodAttribute>();
if (activityMethodAttribute == null)
{
continue;
}
var name = activityMethodAttribute.Name;
if (string.IsNullOrEmpty(name))
{
name = null;
}
if (name == activityMethodName)
{
info.ActivityMethod = method;
break;
}
}
if (info.ActivityMethod == null)
{
throw new ArgumentException($"Activity type [{activityType.FullName}] does not have an entry point method tagged with [ActivityMethod(Name = \"{activityMethodName}\")].");
}
return(info);
}
