Question

我有以下Redux + React组件

import {PropTypes, React, Component} from 'react';
import Select from 'react-select';

class DimensionPicker extends Component {
    componentDidMount() {
        const {onLoad} = this.props;
        onLoad();
    }
    render() {
        const {onChange, attributeList, currentAttribute} = this.props;
        return (
            <div>
                <Select value={currentAttribute} options={attributeList} onChange={onChange} />
            </div>
        )       
    }
}

DimensionPicker.propTypes = {
    dimensionName: PropTypes.string.isRequired,
    onChange: PropTypes.func.isRequired,
    attributeList: PropTypes.arrayOf(PropTypes.shape({
        value: PropTypes.string.isRequired,
        label: PropTypes.string.isRequired
    }).isRequired).isRequired,
    currentAttribute: PropTypes.string.isRequired
}

export default DimensionPicker;

以及以下容器组件

import React from 'react';
import DimensionPickerActions from '../actions/DimensionPickerActions';
import {connect} from 'react-redux';
import DimensionPicker from './controls/DimensionPicker.jsx';

const mapStateToProps = (state) => {
    return {
        dimensionName: state.dimensionName,
        attributeList: state.attributeList,
        currentAttribute: state.currentAttribute
    }
}

const mapDispatchToProps = (state) => {
    return {
        onChange: (newValue) => {
            dispatch(updateAttributeSelection(newValue));
        },
        onLoad: () => {
            dispatch(fetchDimensionAttributes(state.dimensionName));
        }
    }
}

export default connect(mapStateToProps, mapDispatchToProps)(DimensionPicker);

我还有一个缩小器，用于填充初始状态

// define the state tree for the dimenion picker.
const initialState = {
    dimenisionName: '',
    isLoading :'false',
    error : '',
    currentAttribute: '',
    attributeList: []
}

function dimensionPickerReducer(state = initialState, action) {

    switch(action.type) {
        case ATTRIBUTE_SELECTION_CHANGED: 
            return Object.assign({}, state, {currentAttribute: action.data});
            break;
        case REQUEST_DIMENSION_ATTRIBUTES:
            return Object.assign({}, state, {isLoading: 'true', error: ''})
            break;
        case DIMENSION_ATTRIBUTES_RECEIVED:
            return Object.assign({}, state, {attributeList: action.data, isLoading: 'false', error: action.error});
            break;
        case SET_DIMENSION_NAME:
            return Object.assign({}, state, {dimensionName: action.data})
            break;
        default:
            return state;
            break;
    }
}

export default dimensionPickerReducer;

我像这样构建我的状态商店

import React from 'react';
import { createStore, combineReducers, applyMiddleware } from 'redux';
import thunk from 'redux-thunk';
import { Provider } from 'react-redux';
import DataTableReducer from './reducers/DataTableReducer';
import DimensionPickerReducer from './reducers/DimensionPickerReducer';

const combinedReducer = combineReducers({
    dataTable: DataTableReducer,
    dimensionPicker: DimensionPickerReducer
});
export default applyMiddleware(thunk)(createStore)(combinedReducer);

我像

一样加载组件

import React from 'react';
import DimensionPicker from '../containers/DimensionPickerContainer';

const App = () => (
    <div>
    <DimensionPicker dimensionName="Genre"/>
    </div>
    )

export default App;

最后是我加载应用程序的方式

import React from 'react';
import {render} from 'react-dom';
import {Provider} from 'react-redux';
import App from './Reports/App.jsx';
import MovieLensAppStore from './stores/MovieLensAppStore';

render (
    <Provider store={MovieLensAppStore}>
        <App />
    </Provider>,
    document.getElementById('container')
    )

我的期望是

reducer将初始化状态
容器组件将使用容器组件中的2个方法将该状态映射到props
最后，当组件加载时，它将具有状态和可用的调度方法。

但这不会发生。相反，我得到一个警告，如

Warning: Failed propType: Required prop `dimensionName` was not specified in `DimensionPicker`. Check the render method of `Connect(DimensionPicker)`.

我已在此处发布了我的整个代码库

https://github.com/abhitechdojo/MovieLensReact

Answer 1

您将“初始状态”作为默认参数提供给reducer，但这仅用作该reducer实际调用时的默认状态。由于您尚未调度任何操作，因此初始状态取决于您提供给createStore的值，可能是MovieLensAppStore。

我不知道你如何创建你的商店，但这应该有用，例如：

createStore(
    combineReducers({
        dimensionPickerReducer
    }),
    {
        dimensionPicker: {
            dimenisionName: '',
            isLoading :'false',
            error : '',
            currentAttribute: '',
            attributeList: []
        }
    }
)

Answer 2

问题解决了。这里麻烦的一点是combineReducers没有正确初始化状态，这就是容器控件说没有指定道具的原因（因为状态是空的）。

此处记录了解决方案

combineReducers causes code to break

警告：propType失败：在'DimensionPicker`中未指定必需的prop'rensionName`。检查`Connect（DimensionPicker）`

2 个答案: