/// <summary>
/// This is helper method to get event field value from the <see cref="CompositeEvent{T}"/>.
/// </summary>
/// <typeparam name="TEvent">The type of the event handler.</typeparam>
/// <param name="evt">The <see cref="CompositeEvent{T}"/>.</param>
/// <returns>The value of the field holding event handlers.</returns>
///// <exception cref="InvalidOperationException">If the event represented by given <see cref="CompositeEvent{T}"/> is not stored using strong references.</exception>
///// <seealso cref="Qi4CS.Core.API.Model.EventStorage"/>
///// <seealso cref="Qi4CS.Core.API.Model.EventStorageStyleAttribute"/>
public static TEvent GetEventFieldValue <TEvent>(this CompositeEvent <TEvent> evt)
where TEvent : class
{
//// TODO this should actually be a method of CompositeEvent interfaces. Since it is not possible to write this same method cleanly as extension method for CompositeEvent (without the generic parameter)
//if ( ( (CompositeEventSPI) evt ).Model.GetEventStorageKind() != Qi4CS.Core.API.Model.EventStorage.STRONG_REFS )
//{
// throw new InvalidOperationException( "Getting field value of event is only possible for events stored as strong reference." );
//}
return(evt.InvokeFunctionWithRef <EventInfo, TEvent>(ReturnParam));
}
/// <summary>
/// Invokes the <see cref="CompositeStateParticipant{T}.TryInvokeFunctionWithRef"/> method with given delegate, assuming that field type is same as event type.
/// </summary>
/// <typeparam name="TEvent">The type of the property.</typeparam>
/// <param name="evt">The <see cref="CompositeEvent{T}"/>.</param>
/// <param name="function">The delegate to invoke.</param>
/// <returns>The result of <paramref name="function"/>.</returns>
/// <exception cref="InvalidOperationException">If <see cref="CompositeStateParticipant{T}.TryInvokeFunctionWithRef"/> returns <c>false</c>, that is, when the field type does not match <typeparamref name="TEvent"/>.</exception>
/// <remarks>
/// TODO link to documentation about how field type is deduced (it is not always the same as type of property or event).
/// </remarks>
/// <seealso cref="CompositeStateParticipant{T}.TryInvokeFunctionWithRef"/>
public static TEvent InvokeFunctionWithRefSameType <TEvent>(this CompositeEvent <TEvent> evt, FunctionWithRef <TEvent> function)
where TEvent : class
{
return(evt.InvokeFunctionWithRef(function));
}
