observable memory impl

3 files changed, 39 insertions, 77 deletions

diff --git a/packages/web-util/src/hooks/index.ts b/packages/web-util/src/hooks/index.ts
index 393a6fcbb..e5cb54e21 100644
--- a/packages/web-util/src/hooks/index.ts
+++ b/packages/web-util/src/hooks/index.ts
@@ -1,5 +1,5 @@
 export { useLang } from "./useLang.js";
-export { useLocalStorage, useNotNullLocalStorage } from "./useLocalStorage.js";
+export { useLocalStorage } from "./useLocalStorage.js";
 export {
   useAsyncAsHook,
   HookError,
diff --git a/packages/web-util/src/hooks/useLang.ts b/packages/web-util/src/hooks/useLang.ts
index 5b02c5255..9888cc51a 100644
--- a/packages/web-util/src/hooks/useLang.ts
+++ b/packages/web-util/src/hooks/useLang.ts
@@ -14,17 +14,16 @@
  GNU Anastasis; see the file COPYING.  If not, see <http://www.gnu.org/licenses/>
  */
 
-import { useNotNullLocalStorage } from "./useLocalStorage.js";
+import { LocalStorageState, useLocalStorage } from "./useLocalStorage.js";
 
 function getBrowserLang(): string | undefined {
+  if (typeof window === "undefined") return undefined;
   if (window.navigator.languages) return window.navigator.languages[0];
   if (window.navigator.language) return window.navigator.language;
   return undefined;
 }
 
-export function useLang(
-  initial?: string,
-): [string, (s: string) => void, boolean] {
+export function useLang(initial?: string): Required<LocalStorageState> {
   const defaultLang = (getBrowserLang() || initial || "en").substring(0, 2);
-  return useNotNullLocalStorage("lang-preference", defaultLang);
+  return useLocalStorage("lang-preference", defaultLang);
 }
diff --git a/packages/web-util/src/hooks/useLocalStorage.ts b/packages/web-util/src/hooks/useLocalStorage.ts
index ab786db13..264919d37 100644
--- a/packages/web-util/src/hooks/useLocalStorage.ts
+++ b/packages/web-util/src/hooks/useLocalStorage.ts
@@ -19,92 +19,55 @@
  * @author Sebastian Javier Marchano (sebasjm)
  */
 
-import { StateUpdater, useEffect, useState } from "preact/hooks";
+import { useEffect, useState } from "preact/hooks";
+import { localStorageMap, memoryMap } from "../utils/observable.js";
 
+export interface LocalStorageState {
+  value?: string;
+  update: (s: string) => void;
+  reset: () => void;
+}
+
+const supportLocalStorage = typeof window !== "undefined";
+
+const storage = supportLocalStorage ? localStorageMap() : memoryMap<string>();
+
+export function useLocalStorage(
+  key: string,
+  initialValue: string,
+): Required<LocalStorageState>;
+export function useLocalStorage(key: string): LocalStorageState;
 export function useLocalStorage(
   key: string,
   initialValue?: string,
-): [string | undefined, StateUpdater<string | undefined>] {
+): LocalStorageState {
   const [storedValue, setStoredValue] = useState<string | undefined>(
     (): string | undefined => {
-      return typeof window !== "undefined"
-        ? window.localStorage.getItem(key) || initialValue
-        : initialValue;
+      return storage.get(key) ?? initialValue;
     },
   );
 
   useEffect(() => {
-    const listener = buildListenerForKey(key, (newValue) => {
+    return storage.onUpdate(key, () => {
+      const newValue = storage.get(key);
+      console.log("new value", key, newValue);
       setStoredValue(newValue ?? initialValue);
     });
-    window.addEventListener("storage", listener);
-    return () => {
-      window.removeEventListener("storage", listener);
-    };
   }, []);
 
-  const setValue = (
-    value?: string | ((val?: string) => string | undefined),
-  ): void => {
-    setStoredValue((p) => {
-      const toStore = value instanceof Function ? value(p) : value;
-      if (typeof window !== "undefined") {
-        if (!toStore) {
-          window.localStorage.removeItem(key);
-        } else {
-          window.localStorage.setItem(key, toStore);
-        }
-      }
-      return toStore;
-    });
-  };
-
-  return [storedValue, setValue];
-}
-
-function buildListenerForKey(
-  key: string,
-  onUpdate: (newValue: string | undefined) => void,
-): () => void {
-  return function listenKeyChange() {
-    const value = window.localStorage.getItem(key);
-    onUpdate(value ?? undefined);
-  };
-}
-
-//TODO: merge with the above function
-export function useNotNullLocalStorage(
-  key: string,
-  initialValue: string,
-): [string, StateUpdater<string>, boolean] {
-  const [storedValue, setStoredValue] = useState<string>((): string => {
-    return typeof window !== "undefined"
-      ? window.localStorage.getItem(key) || initialValue
-      : initialValue;
-  });
-
-  useEffect(() => {
-    const listener = buildListenerForKey(key, (newValue) => {
-      setStoredValue(newValue ?? initialValue);
-    });
-    window.addEventListener("storage", listener);
-    return () => {
-      window.removeEventListener("storage", listener);
-    };
-  });
-
-  const setValue = (value: string | ((val: string) => string)): void => {
-    const valueToStore = value instanceof Function ? value(storedValue) : value;
-    setStoredValue(valueToStore);
-    if (typeof window !== "undefined") {
-      if (!valueToStore) {
-        window.localStorage.removeItem(key);
-      } else {
-        window.localStorage.setItem(key, valueToStore);
-      }
+  const setValue = (value?: string): void => {
+    if (!value) {
+      storage.delete(key);
+    } else {
+      storage.set(key, value);
     }
   };
 
-  const isSaved = window.localStorage.getItem(key) !== null;
-  return [storedValue, setValue, isSaved];
+  return {
+    value: storedValue,
+    update: setValue,
+    reset: () => {
+      setValue(initialValue);
+    },
+  };
 }