Pull the foreign document updating into a utility method and add it to the GenericPopoverMixin

module/Apps/GenericApp.mjs

@@ -1,4 +1,4 @@
-import { createItemFromElement, deleteItemFromElement, editItemFromElement } from "./utils.mjs";
+import { createItemFromElement, deleteItemFromElement, editItemFromElement, updateForeignDocumentFromEvent } from "./utils.mjs";
 import { DicePool } from "./DicePool.mjs";
 import { RichEditor } from "./RichEditor.mjs";
 import { toBoolean } from "../consts.mjs";
@@ -77,7 +77,7 @@ export function GenericAppMixin(HandlebarsApp) {
 			this.element.querySelectorAll(`input[data-foreign-update-on]`).forEach(el => {
 				const events = el.dataset.foreignUpdateOn.split(`,`);
 				for (const event of events) {
-					el.addEventListener(event, this.updateEmbedded);
+					el.addEventListener(event, updateForeignDocumentFromEvent);
 				};
 			});
 		};
@@ -150,22 +150,6 @@ export function GenericAppMixin(HandlebarsApp) {
 			});
 			app.render({ force: true });
 		};
-
-		/**
-		 * @param {Event} event
-		 */
-		async updateForeign(event) {
-			const target = event.currentTarget;
-			const data = target.dataset;
-			const document = await fromUuid(data.foreignUuid);
-
-			let value = target.value;
-			switch (target.type) {
-				case `checkbox`: value = target.checked; break;
-			};
-
-			await document?.update({ [data.foreignName]: value });
-		};
 		// #endregion
 	};
 	return GenericRipCryptApp;

module/Apps/popovers/GenericPopoverMixin.mjs

@@ -1,3 +1,5 @@
+import { updateForeignDocumentFromEvent } from "../utils.mjs";
+
 const { ApplicationV2 } = foundry.applications.api;
 
 /**
@@ -65,6 +67,23 @@ export function GenericPopoverMixin(HandlebarsApp) {
 			};
 		};
 
+		async _onRender(...args) {
+			await super._onRender(...args);
+
+			/*
+			Foreign update listeners so that we can easily update items that may not
+			be this document itself, but are useful to be able to be edited from this
+			sheet. Primarily useful for editing the Actors' Item collection, or an Items'
+			ActiveEffect collection.
+			*/
+			this.element.querySelectorAll(`input[data-foreign-update-on]`).forEach(el => {
+				const events = el.dataset.foreignUpdateOn.split(`,`);
+				for (const event of events) {
+					el.addEventListener(event, updateForeignDocumentFromEvent);
+				};
+			});
+		};
+
 		async close(options = {}) {
 			// prevent locked popovers from being closed
 			if (this.popover.locked && !options.force) { return };

module/Apps/utils.mjs

@@ -42,3 +42,24 @@ export async function deleteItemFromElement(target) {
 	const item = await fromUuid(itemId);
 	item.delete();
 };
+
+/**
+ * Updates a document using the UUID, expects there to be the following
+ * dataset attributes:
+ *   - "data-foreign-uuid" : The UUID of the document to update
+ *   - "data-foreign-name" : The dot-separated path of the value to update
+ *
+ * @param {Event} event
+ */
+export async function updateForeignDocumentFromEvent(event) {
+	const target = event.currentTarget;
+	const data = target.dataset;
+	const document = await fromUuid(data.foreignUuid);
+
+	let value = target.value;
+	switch (target.type) {
+		case `checkbox`: value = target.checked; break;
+	};
+
+	await document?.update({ [data.foreignName]: value });
+};