README.md

FreshMint Store

Another lightweight state management library that is compatible with Preact/React and has an external store interface to share state among Fresh islands. The library should offer a simple way to manage the state of your islands and allow for saving state data to different storage options, such as the window, sessionStorage, and localStorage.

Usage

First import the preactCreateStore function:

import { preactCreateStore } from "@mint/preact.ts";

Then create a store with an optional initial state and options:

const initialState = { count: 0 };
const [useStore, setState] = preactCreateStore(initialState);

Now, you can use the useStore hook in your components to access the state:

import { preactCreateStore } from "@mint/preact.ts";

const [useState, setState] = preactCreateStore(2);

export default function Counter() {
  const state = useState();
  return (
    <div class="flex gap-2 w-full">
      <p>Counter</p>
      <p class="flex-grow-1 font-bold text-xl">{state}</p>
      <Button
        onClick={() => {
          setState(state - 1);
        }}
      >
        -1
      </Button>
      <Button
        onClick={() => {
          setState(state + 1);
        }}
      >
        +1
      </Button>
    </div>
  );
}

If you need to access state from multiple islands, it can be useful to keep a storage file and import the preactCreateStore result hooks from there.

// store.ts
export const [useState, setState] = preactCreateStore({counter: 2});

// Counter.tsx
import { setState, useState } from "../stores.ts";
...

Note that you can pass namespaces to your stores if needed. However, keep in mind that stores with the same namespace will share the same object, which can break your components if not handled properly.

The CreateStoreOptions object allows you to configure the behavior of your store:

• namespace: A custom namespace for your store. Defaults to a random namespace.
• provider: The storage provider to use ("window", "sessionStore", "localStorage"). Defaults to "window". Be careful when choosing between session or localStorage. While it can be helpful to share state across pages, it can also add complexity and introduce non-deterministic bugs.
• forceInitial: A boolean indicating whether to use the initial state passed to the store, even if there's data in the storage. Defaults to false. For example:

const options = {
  namespace: "customNamespace",
  provider: "localStorage",
  forceInitial: true,
};

const [useStore, setState] = preactCreateStore(initialState, options);

preactCreateStore is a simplification of the following code. If you are using a library other than Preact, it can be useful to integrate this functionality.

import { useSyncExternalStore } from "preact/compat";
import { createStore, StoreAPI } from "@mint/mod.ts";

function useStore<State>(store: StoreAPI<State>) {
  return useSyncExternalStore(store.subscribe, store.getState);
}
const options = {};
const store = createStore(2, options);

export default function Counter() {
  const state = useStore(store);
  return (
    <Button
      onClick={() => {
        store.setState(state - 1);
      }}
    >
      -1
    </Button>
  );
}