~~~
function isPromise(obj){
return !!obj
&&(typeof obj ==='object' || typeof obj ==='function')
&&typeof obj.then == 'function';
}
export default function({getState,dispatch}){
//getState用來獲取倉庫狀態 dispatch用來重新開派發動作
return function(next){//next是為了調用原生的dispatch方法
return function(action){
return isPromise(action.payload)?action.payload.then(function(result){
dispatch({...action,payload:result});
}).catch(error=>{
dispatch({...action,payload:error,error:true});
return Promise.reject(error);
}):next(action);
}
}
}
~~~
## 附錄
* [redux](https://github.com/reduxjs/redux)
* [redux-logger](https://github.com/LogRocket/redux-logger)
* [redux-promise](https://github.com/redux-utilities/redux-promise)
* [redux-thunk](https://github.com/reduxjs/redux-thunk)
* [redux-persist](https://github.com/rt2zz/redux-persist)
* [redux-immutable](https://www.npmjs.com/package/redux-immutable)
* [immutable-js](https://immutable-js.github.io/immutable-js)
* [reselect](https://github.com/reduxjs/reselect)
