WIP

Author: Gudahtt

packages/base-controller/src/Messenger.ts

@@ -372,6 +372,14 @@ export class Messenger<
     getPayload: () => ExtractEventPayload<Event, EventType>;
   }) {
     this.#initialEventPayloadGetters.set(eventType, getPayload);
+    const delegationTargets =
+      this.#subscriptionDelegationTargets.get(eventType);
+    if (!delegationTargets) {
+      return;
+    }
+    for (const messenger of delegationTargets.keys()) {
+      messenger.registerDelegatedInitialEventPayload({ eventType, getPayload });
+    }
   }
 
   /**
@@ -619,10 +627,10 @@ export class Messenger<
         typeof eventType
       >;
       let delegatedEventSubscriptions =
-        this.#delegatedEventSubscriptions.get(eventType);
+        this.#subscriptionDelegationTargets.get(eventType);
       if (!delegatedEventSubscriptions) {
         delegatedEventSubscriptions = new Map();
-        this.#delegatedEventSubscriptions.set(
+        this.#subscriptionDelegationTargets.set(
           eventType,
           delegatedEventSubscriptions,
         );
@@ -639,6 +647,55 @@ export class Messenger<
     }
   }
 
+  /**
+   * Revoke delegated actions and/or events from another messenger.
+   *
+   * @param args - Arguments.
+   * @param args.actions - The action types to revoke.
+   * @param args.events - The event types to revoke.
+   * @param args.messenger - The messenger these actions/events were delegated to.
+   */
+  revoke<DelegatedAction extends Action, DelegatedEvent extends Event>({
+    actions = [],
+    events = [],
+    messenger,
+  }: {
+    actions?: DelegatedAction['type'][];
+    events?: DelegatedEvent['type'][];
+    messenger: DelegatedMessenger<DelegatedAction, DelegatedEvent>;
+  }) {
+    for (const actionType of actions) {
+      const delegationTargets = this.#actionDelegationTargets.get(actionType);
+      if (!delegationTargets || !delegationTargets.has(messenger)) {
+        // Nothing to revoke
+        continue;
+      }
+      messenger.unregisterDelegatedActionHandler(actionType);
+      delegationTargets.delete(messenger);
+      if (delegationTargets.size === 0) {
+        this.#actionDelegationTargets.delete(actionType);
+      }
+    }
+    for (const eventType of events) {
+      const delegationTargets =
+        this.#subscriptionDelegationTargets.get(eventType);
+      if (!delegationTargets) {
+        // Nothing to revoke
+        continue;
+      }
+      const delegatedSubscriber = delegationTargets.get(messenger);
+      if (!delegatedSubscriber) {
+        // Nothing to revoke
+        continue;
+      }
+      this.unsubscribe(eventType, delegatedSubscriber);
+      delegationTargets.delete(messenger);
+      if (delegationTargets.size === 0) {
+        this.#subscriptionDelegationTargets.delete(eventType);
+      }
+    }
+  }
+
   /**
    * Determine whether the given name is within the current namespace.
    *