使用反应在商店文件中创建过滤器答案

【问题标题】：Create filter in a store file with react使用反应在商店文件中创建过滤器
【发布时间】：2021-06-26 22:09:35
【问题描述】：

大家晚上好我有这个过滤功能，我想在一个名为“post.action”的商店文件中使用：

filtering = (e) => {
    let filtering = e.target.value
    if(filtering === ""){
        this.setState({
            filters:filtering,
            posts:posts
        })
    } else {
        this.setState({
            filters:filtering,
            posts:posts.filter(posts=>{
                return country.filtres.indexOf(e.target.value)>=0
            })
        })

所以我想将此功能集成到我的商店中。到目前为止，我一直坚持这一点：

export const filterCountries = (posts, filtering) => (dispatch) => {
    return dispatch({
        type:FILTER_COUNTRY,
        payload:{
           
            ),

如何在“有效负载”之后集成它？希望它足够清楚。提前谢谢！

【问题讨论】：

在我看来，过滤操作应该只在状态中设置一个属性filter。实际的过滤可以在选择器函数中完成。

标签： reactjs redux filter store

【解决方案1】：

正如琳达所说；你应该过滤selector，这里是一个例子：

const { Provider, useDispatch, useSelector } = ReactRedux;
const { createStore, applyMiddleware, compose } = Redux;
const { createSelector } = Reselect;

const initialState = {
  data: ['aaa', 'aab', 'abb', 'bbb'],
  filter: '',
};
//action types
const SET_FILTER = 'SET_FILTER';
//action creators
const setFilter = (filter) => ({
  type: SET_FILTER,
  payload: filter,
});
const reducer = (state, { type, payload }) => {
  if (type === SET_FILTER) {
    return {
      ...state,
      filter: payload,
    };
  }
  return state;
};
//selectors
const selectData = (state) => state.data;
const createSelectFilteredData = (filter) =>
  createSelector(
    [selectData], //re use select data
    (data) => data.filter((d) => d.includes(filter))
  );
const selectFilter = (state) => state.filter;
//creating store with redux dev tools
const composeEnhancers =
  window.__REDUX_DEVTOOLS_EXTENSION_COMPOSE__ || compose;
const store = createStore(
  reducer,
  initialState,
  composeEnhancers(
    applyMiddleware(() => (next) => (action) =>
      next(action)
    )
  )
);
const Filter = React.memo(function FilterComponent() {
  const filter = useSelector(selectFilter);
  const dispatch = useDispatch();
  return (
    <label>
      Filter
      <input
        type="text"
        value={filter}
        onChange={(e) =>
          dispatch(setFilter(e.target.value))
        }
      />
    </label>
  );
});
const FilteredList = React.memo(
  function FilteredListComponent() {
    const filter = useSelector(selectFilter);
    const selectFiltered = React.useMemo(
      () => createSelectFilteredData(filter),
      [filter]
    );
    const data = useSelector(selectFiltered);
    return (
      <ul>
        {data.map((d, i) => (
          <li key={i}>{d}</li>
        ))}
      </ul>
    );
  }
);
const App = () => {
  return (
    <div>
      <Filter />
      <FilteredList />
    </div>
  );
};

ReactDOM.render(
  <Provider store={store}>
    <App />
  </Provider>,
  document.getElementById('root')
);

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.8.4/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.8.4/umd/react-dom.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/redux/4.0.5/redux.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-redux/7.2.0/react-redux.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/reselect/4.0.0/reselect.min.js"></script>
<div id="root"></div>

【讨论】：

非常感谢您的帮助！