From 9b34b949a62f90bb04127e94330eeeea5e0fb1e8 Mon Sep 17 00:00:00 2001
From: Hornwitser <github@hornwitser.no>
Date: Wed, 9 Jun 2021 13:18:24 +0200
Subject: [PATCH] Accept invalid IDs in useSlave and useInstance

Gracefully handle invalid IDs in useSlave and useInstance as this is
necessary when when the ID isn't known by the component using the hook,
since it can't conditionally call the hook.
---
 packages/web_ui/src/model/instance.jsx | 11 +++++------
 packages/web_ui/src/model/slave.jsx    |  9 ++++-----
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/packages/web_ui/src/model/instance.jsx b/packages/web_ui/src/model/instance.jsx
index 5b027d3a..ef4f27a2 100644
--- a/packages/web_ui/src/model/instance.jsx
+++ b/packages/web_ui/src/model/instance.jsx
@@ -10,21 +10,20 @@ export function useInstance(id) {
 	let [instance, setInstance] = useState({ loading: true });
 
 	function updateInstance() {
-		if (!Number.isInteger(id)) {
-			setInstance({ missing: true });
-			return;
-		}
-
 		libLink.messages.getInstance.send(control, { id }).then(result => {
 			setInstance({ ...result, present: true });
 		}).catch(err => {
-			logger.log(`Failed to get instance: ${err}`);
+			logger.error(`Failed to get instance: ${err}`);
 			setInstance({ missing: true });
 		});
 
 	}
 
 	useEffect(() => {
+		if (!Number.isInteger(id)) {
+			setInstance({ missing: true });
+			return undefined;
+		}
 		updateInstance();
 
 		function updateHandler(newInstance) {
diff --git a/packages/web_ui/src/model/slave.jsx b/packages/web_ui/src/model/slave.jsx
index c29e7405..729e671a 100644
--- a/packages/web_ui/src/model/slave.jsx
+++ b/packages/web_ui/src/model/slave.jsx
@@ -9,11 +9,6 @@ export function useSlave(id) {
 	let [slave, setSlave] = useState({ loading: true });
 
 	function updateSlave() {
-		if (!Number.isInteger(id)) {
-			setSlave({ missing: true });
-			return;
-		}
-
 		// XXX optimize by requesting only the slave in question
 		libLink.messages.listSlaves.send(control).then(result => {
 			let match = result.list.find(i => i.id === id);
@@ -26,6 +21,10 @@ export function useSlave(id) {
 	}
 
 	useEffect(() => {
+		if (!Number.isInteger(id)) {
+			setSlave({ missing: true });
+			return undefined;
+		}
 		updateSlave();
 
 		function updateHandler(newSlave) {