~~~
export default function combineReducers(reducers){
let reducerKeys = Object.keys(reducers);//[counter1,counter2]
return function (state={},action){
let hasChanged = false;//此次派發動作是否引起了狀態的修改，或者說狀態的改變
const nextState = {};
for(let i=0;i<reducerKeys.length;i++){
const key = reducerKeys[i];//counter1
const previousStateForKey = state[key];//{number:0}
const reducer = reducers[key];//counter1
let nextStateForKey = reducer(previousStateForKey,action);//{type:'ADD1'} {number:1}
nextState[key] = nextStateForKey;
hasChanged = hasChanged||nextStateForKey!==previousStateForKey;
}
return hasChanged?nextState:state;
}
}
~~~
~~~
export default function bindActionCreators(actionCreators,dispatch){
function bindActionCreator(actionCreator, dispatch){
return (...args)=>dispatch(actionCreator(...args));
}
if(typeof actionCreators == 'function'){
return bindActionCreator(actionCreators,dispatch);
}
let boundActionCreators = {};
for(let key in actionCreators){
boundActionCreators[key] = bindActionCreator(actionCreators[key],dispatch);
}
return boundActionCreators;
}
~~~
