Create LocalStorageState.svelte.ts

Author: hhvrc

src/lib/stores/LocalStorageState.svelte.ts

@@ -0,0 +1,30 @@
+import { browser } from '$app/environment';
+
+export class LocaleStorageState<T> {
+  #key: string;
+  #default: T;
+  #value: T;
+
+  constructor(key: string, defaultValue: T) {
+    this.#key = key;
+    this.#default = defaultValue;
+
+    const existingValue = browser ? localStorage.getItem(key) : null;
+    this.#value = $state<T>(
+      existingValue === null ? defaultValue : (JSON.parse(existingValue) as T)
+    );
+  }
+
+  get Value() {
+    return this.#value;
+  }
+  set Value(value: T) {
+    this.#value = value;
+    localStorage.setItem(this.#key, JSON.stringify(value));
+  }
+
+  Reset() {
+    this.#value = this.#default;
+    localStorage.removeItem(this.#key);
+  }
+}