20219: Replace API & websocket log loading with webdav polling

[arvados-workbench2.git] / src / common / use-async-interval.ts

diff --git a/src/common/use-async-interval.ts b/src/common/use-async-interval.ts
new file mode 100644 (file)
index 0000000..8951a9b
--- /dev/null
+++ b/src/common/use-async-interval.ts
@@ -0,0 +1,35 @@
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
+var react = require("react");
+
+export const useAsyncInterval = function (callback, delay) {
+    const savedCallback = react.useRef();
+    const active = react.useRef(false);
+
+    // Remember the latest callback.
+    react.useEffect(() => {
+        savedCallback.current = callback;
+    }, [callback]);
+    // Set up the interval.
+    react.useEffect(() => {
+        // useEffect doesn't like async callbacks (https://github.com/facebook/react/issues/14326) so create nested async callback
+        (async () => {
+            // Make tick() async
+            async function tick() {
+                if (active.current) {
+                    // If savedCallback is not set yet, no-op until it is
+                    savedCallback.current && await savedCallback.current();
+                    setTimeout(tick, delay);
+                }
+            }
+            if (delay !== null) {
+                active.current = true;
+                setTimeout(tick, delay);
+            }
+        })(); // Call nested async function
+        // We return the teardown function here since we can't from inside the nested async callback
+        return () => {active.current = false;};
+    }, [delay]);
+};