07. 从零开始编写Store
了解一下Redux的createStore()方法实际创建Store的过程
const createStore = (reducer) => {
let state;
let listeners = [];
const getState = () => state;
const dispatch =(action) => {
state = reducer(state, action);
listeners.forEach(listener => listener());
};
const subscribe = (listener) => {
listeners.push(listener);
return () => {
listeners = listeners.filter(l => l !== listener);
}
}
dispatch({});
return { getState, dispatch, subscribe };
}
//最终代码 http://jsbin.com/lecuwat/edit?js,output