createEffect

Creates an effect that runs when the store’s state changes.

const effect = createEffect(store, effectFn, dependencyFn?);

Parameters

• store - The store instance to subscribe to
• effectFn - The function to run when dependencies change. Receives the current state as argument.
• dependencyFn? - Optional function that returns an array of dependencies. If provided, the effect will only run when these dependencies change.

Returns

An Effect object with the following methods:

• mount - Start listening to changes in the original store.
• unmount - Stop listening to changes in the original store.

Usage

import { createEffect } from "dharma-core";
import { counterStore } from "./counterStore";

const countLogger = createEffect(
  counterStore,
  (state) => console.log("count =", state.count),
  (state) => [state.count],
);

countLogger.mount();