ActionGroup

@MainActor
public final class ActionGroup<ContentType> : ActionPerformableCollection where ContentType : ContentTypeable

A group of actions which run concurrently, merging their results into one content value.

The child requests all run concurrently and receive the same input content. When they complete, a ActionResultsMerging object merges their results into a single content value. The group passes this content value and all of the group’s child results via a single ActionResult, and passes the merged value on through its output conduit.

Child failure behavior

Each child’s shouldEndParentTaskOnFailure flag controls what happens when that child fails:

• true: The group immediately calls cancelAll() on its remaining siblings, builds a group-level ActionResult containing all results collected up to that point plus the failing child’s failure result, and returns cancelled(partialResults:). Siblings that had not yet completed are cancelled.

• false: The group records the failure and lets all remaining siblings run to completion. Once every child has finished, the group builds a single group-level ActionResult whose origin property includes child results for every task’s success or failure in declaration order, then returns cancelled(partialResults:). The merger is not called because not all children succeeded.

In both cases the caller receives one group ActionResult with a group(results:) origin. Use failedActions() on the partial results to inspect which children failed.

Usage

Build a group by composing child ActionConfiguration objects inside an ActionGroupConfiguration. You can either assign this configuration to interactorsData and run it via its associated event type, or you can build these configurations within a state model and call performActions(configuration:content:) on its Destination.

// Each child configuration represents one parallel Interactor request.
let retrievalChildren: [any ActionConfiguring<InteractorType, ContentType>] = [
    ActionConfiguration<InteractorType, ContentType, MyInteractor>(
        interactorType: .myType,
        action: .retrieveFile,
        assistant: .basicAsync,
        identifier: ActionIdentifier.retrieve),
    ActionConfiguration<InteractorType, ContentType, MyInteractor>(
        interactorType: .myType,
        action: .retrieveFile,
        assistant: .basicAsync,
        identifier: ActionIdentifier.retrieve)
]

// The merger combines each child's result into a single ContentType value.
let retrievals = ActionGroupConfiguration<InteractorType, ContentType>(
    actions: retrievalChildren,
    merger: FileMerger(),
    identifier: ActionIdentifier.retrievalGroup)

let result = await destination.performActions(configuration: retrievals, content: nil)

if case .success(let outputs) = result,
   let groupResult = outputs.last(identifier: ActionIdentifier.retrievalGroup) {
    // groupResult.content holds the merged value from all parallel children.
}