想要返回不同的值從相同reducer在reactjs

-2

import {FETCH_OBSERVATION} from '../actions/index'; 
import {DELETE_OBSERVATION} from '../actions/index'; 

export default function(state={all:[],count:null},action){ 
    switch (action.type) { 
    case FETCH_OBSERVATION: 
    console.log("data for fetch observationCount",action.payload.data.model.observationInstanceList); 

    return{ 
     all:state.all.concat(action.payload.data.model.observationInstanceList), 
     count:action.payload.data.model.observationCount 
    } 
    case DELETE_OBSERVATION: 
    return state.all=[]; 
    default: 
    return state 

    } 
    return state; 
}

我使用行動/索引文件中的動作創建者定義從API中提取數據。有人可以告訴我爲什麼state.all.concat沒有定義？想要返回不同的值從相同reducer在reactjs

錯誤是這個樣子

Cannot read property 'concat' of undefined 
at ./src/reducers/reducer_observation.js.__webpack_exports__.a (reducer_observation.js:10) 
at combination (combineReducers.js:120) 
at dispatch (createStore.js:165) 
at redux-logger.js:1 
at index.js:28 
at dispatch (applyMiddleware.js:35) 
at action.payload.then._extends.payload (index.js:25) 
at <anonymous>

我結合減速這個樣子

import { combineReducers } from 'redux'; 
import SpeciesChartReducer from './reducer_chart_data'; 
import ObservationReducer from './reducer_observation'; 
import TaxonReducer from './reducer_taxon_list'; 
import UserGroupNames from './reducer_fetch_userGroup'; 
import UserGroupObservations from './reducer_fetch_groupobservations'; 
import HomeTotalCount from './reducer_home_total_count'; 

const rootReducer = combineReducers({ 
    Observation:ObservationReducer, 
    ChartData:SpeciesChartReducer, 
    treeData:TaxonReducer, 
    UserGroupNames:UserGroupNames, 
    UserGroupObservations:UserGroupObservations, 
    HomeTotalCount:HomeTotalCount 
}); 

export default rootReducer;

來源

2017-08-08 user2903536

你到底用'的console.log thing'是什麼意思？這個：'action.payload.data.model.observationInstanceList'？ – Denialos

用'return state.all = [];'你正在改變狀態並返回一個不同形狀的狀態。我很確定那不是你想要做的。您可能想要再次返回默認狀態。最好把它解壓到'const'。例如：'const DEFAULT_STATE = {all：[]，count：null};'在reducer外部，內部：'function（state = DEFAULT_STATE，action）{'及以後：case DELETE_OBSERVATION：return DEFAULT_STATE;'。 – Yoshi

其實我在觀察頁面上實現過濾器。因此，一旦新的過濾器應用我想刪除顯示的觀察，並加載新的觀察，這就是爲什麼我做這個「state.all：[]」後刪除前一個。如果你有任何想法，請分享考慮上述情況。我正在開發的項目是OpenSource，你可以在這裏看看功能網站。 http://indiabiodiversity.org/observation/list?view=list 上面的頁面是我想要實現的。 – user2903536

好了，所以如果u希望上面的函數的工作，然後做這樣的。

import {FETCH_OBSERVATION} from '../actions/index'; 
import {DELETE_OBSERVATION} from '../actions/index'; 
const DEFAULT_STATE={all:[],count:null} 
export default function(state=DEFAULT_STATE,action){ 
    switch (action.type) { 
    case FETCH_OBSERVATION: 
    return{ 
     all:state.all.concat(action.payload.data.model.observationInstanceList), 
     count:action.payload.data.model.observationCount 
    } 
    case DELETE_OBSERVATION: 
    return DEFAULT_STATE; 
    default: 
    return DEFAULT_STATE 

    } 
    return DEFAULT_STATE; 
}

來源

2017-08-12 22:56:29 user2903536

想要返回不同的值從相同reducer在reactjs

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