1 files changed, 14 insertions, 0 deletions
diff --git a/Timeline/ClientApp/src/app/data/queue.ts b/Timeline/ClientApp/src/app/data/queue.ts
new file mode 100644
index 00000000..001340a9
--- /dev/null
+++ b/Timeline/ClientApp/src/app/data/queue.ts
@@ -0,0 +1,14 @@
+const queueMap = new Map<string, Promise<null>>();
+
+export function queue<T>(key: string, func: () => Promise<T>): Promise<T> {
+  const last = queueMap.get(key);
+  if (last == null) {
+    const promise = func();
+    queueMap.set(key, promise.then(null, null));
+    return promise;
+  } else {
+    const promise = last.then(() => func());
+    queueMap.set(key, promise.then(null, null));
+    return promise;
+  }
+}