merge new_starr_app@qas history into apps/web

git-subtree-dir: apps/web
git-subtree-mainline: eaa6d2276a
git-subtree-split: 459af9d46a

apps/web/lib/ocaml/AnnotationStorage.res

@@ -0,0 +1,20 @@
+@val external localStorage: {..} = "localStorage"
+
+let storageKey = (courseId: string, lessonId: string) =>
+  `annotation:${courseId}:${lessonId}`
+
+let saveNote = (courseId: string, lessonId: string, note: string) => {
+  let key = storageKey(courseId, lessonId)
+  localStorage["setItem"](key, note)
+}
+
+let loadNote = (courseId: string, lessonId: string) => {
+  let key = storageKey(courseId, lessonId)
+  let value: Nullable.t<string> = localStorage["getItem"](key)
+  Nullable.toOption(value)
+}
+
+let deleteNote = (courseId: string, lessonId: string) => {
+  let key = storageKey(courseId, lessonId)
+  localStorage["removeItem"](key)
+}