Vanilla Redux 示例(不含 React 或其他)
你可以点击此处查看正在运行的演示。
HTML:
<p>
<span>Counter State</span><br />
(<em>Will increase each minute</em>):
<p>
<span id="counter-state" style="font-weight: bolder"></span>
</p>
</p>
<p>
<button id="increment-action">+ Increase +</button>
<button id="decrement-action">- Decrease -</button>
</p>
REDUX LOGIC:
// ------------------------ reducer helpers ------------------------
let reducers = {}
let addReducer = (reducers, actionType, reducer) =>
reducers[actionType] = (state, action) => {
if (action.type == actionType) {
return reducer(state, action)
}
}
let reducer = (state, action) => {
if (reducers[action.type]) {
return reducers[action.type](state, action)
}
return state
}
// ------------------------ redux setup ------------------------
const {
createStore,
applyMiddleware
} = Redux
// apply logging middleware (not necessary)
// open the console to see the action logger output on each time new action dispatched
const actionLogger = ({ dispatch, getState }) => next => action => {
console.log("action logger: action.type=%s state=%d", action.type, getState())
return next(action)
}
// ------------------------ reducers ------------------------
// those will be creating new states and returning it,
// depending on the dispatched actions
addReducer(reducers, 'INCREMENT', (state, action) => ++state)
addReducer(reducers, 'DECREMENT', (state, action) => --state)
const DEFAULT_STATE = 0
const store = createStore(
reducer,
DEFAULT_STATE,
applyMiddleware(actionLogger)
);
console.log(createStore)
// ------------------------ rendering ------------------------
let render = () => document.getElementById('counter-state').innerHTML = store.getState()
//
// IMPORTANT BINDING:
//
// store will be dispatching the new state to the render method each time the state changes
//
store.subscribe(render)
//
// render with the state for the first time
//
render()
// ------------------------ redux actions ------------------------
// continously increment the counter (the state) each second
setInterval(() => store.dispatch({type: 'INCREMENT'}), 1000)
// only increment the counter on click to the increase button
document
.getElementById('increment-action')
.addEventListener('click', () => store.dispatch({type: 'INCREMENT'}))
// only decrement the counter on click to the decrease button
document
.getElementById('decrement-action')
.addEventListener('click', () => store.dispatch({type: 'DECREMENT'}))