Files
eewing cf73cd3b4c INIT
2026-02-17 14:10:16 -06:00

118 lines
4.3 KiB
JavaScript

import { defaultWindow } from "../../internal/configurable-globals.js";
import { on } from "svelte/events";
import { createSubscriber } from "svelte/reactivity";
function getStorage(storageType, window) {
switch (storageType) {
case "local":
return window.localStorage;
case "session":
return window.sessionStorage;
}
}
function proxy(value, root, proxies, subscribe, update, serialize) {
if (value === null || typeof value !== "object") {
return value;
}
const proto = Object.getPrototypeOf(value);
if (proto !== null && proto !== Object.prototype && !Array.isArray(value)) {
return value;
}
let p = proxies.get(value);
if (!p) {
p = new Proxy(value, {
get: (target, property) => {
subscribe?.();
return proxy(Reflect.get(target, property), root, proxies, subscribe, update, serialize);
},
set: (target, property, value) => {
update?.();
Reflect.set(target, property, value);
serialize(root);
return true;
},
});
proxies.set(value, p);
}
return p;
}
/**
* Creates reactive state that is persisted and synchronized across browser sessions and tabs using Web Storage.
* @param key The unique key used to store the state in the storage.
* @param initialValue The initial value of the state if not already present in the storage.
* @param options Configuration options including storage type, serializer for complex data types, and whether to sync state changes across tabs.
*
* @see {@link https://runed.dev/docs/utilities/persisted-state}
*/
export class PersistedState {
#current;
#key;
#serializer;
#storage;
#subscribe;
#update;
#proxies = new WeakMap();
constructor(key, initialValue, options = {}) {
const { storage: storageType = "local", serializer = { serialize: JSON.stringify, deserialize: JSON.parse }, syncTabs = true, } = options;
const window = "window" in options ? options.window : defaultWindow; // window is not mockable to be undefined without this, because JavaScript will fill undefined with `= default`
this.#current = initialValue;
this.#key = key;
this.#serializer = serializer;
if (window === undefined)
return;
const storage = getStorage(storageType, window);
this.#storage = storage;
const existingValue = storage.getItem(key);
if (existingValue !== null) {
this.#current = this.#deserialize(existingValue);
}
else {
this.#serialize(initialValue);
}
this.#subscribe = createSubscriber((update) => {
this.#update = update;
const cleanup = syncTabs && storageType === "local"
? on(window, "storage", this.#handleStorageEvent)
: null;
return () => {
cleanup?.();
this.#update = undefined;
};
});
}
get current() {
this.#subscribe?.();
const storageItem = this.#storage?.getItem(this.#key);
const root = storageItem ? this.#deserialize(storageItem) : this.#current;
return proxy(root, root, this.#proxies, this.#subscribe?.bind(this), this.#update?.bind(this), this.#serialize.bind(this));
}
set current(newValue) {
this.#serialize(newValue);
this.#update?.();
}
#handleStorageEvent = (event) => {
if (event.key !== this.#key || event.newValue === null)
return;
this.#current = this.#deserialize(event.newValue);
this.#update?.();
};
#deserialize(value) {
try {
return this.#serializer.deserialize(value);
}
catch (error) {
console.error(`Error when parsing "${value}" from persisted store "${this.#key}"`, error);
return;
}
}
#serialize(value) {
try {
if (value != undefined) {
this.#storage?.setItem(this.#key, this.#serializer.serialize(value));
}
}
catch (error) {
console.error(`Error when writing value from persisted store "${this.#key}" to ${this.#storage}`, error);
}
}
}