如何在 Redux 中为每个实例创建一个商店? [英] How to create one store per instance in Redux?
问题描述
有时在 Redux 应用程序中为每个实例创建一个存储会很有用.Redux 的创建者自己创建了一个 Gist，描述了如何实现这一点:https://gist.github.com/gaearon/eeee2f619620ab7b55673a4ee2bf8400
Sometimes it would be useful to create one store per instance in Redux applications. The creator of Redux itself created a Gist which describes how to achieve this: https://gist.github.com/gaearon/eeee2f619620ab7b55673a4ee2bf8400
我已经在 Gist 中问过这个问题，但我认为 StackOverflow 更适合回答这个问题:
I asked this question already in the Gist but I think StackOverflow would be a better place for this question:
我想知道如何将动作dispatch 到组件自己的特殊存储?有没有办法访问 <Provider/> 的 store-prop 的每个 <SubApp/>(以及它们的子组件)?
I wonder how to dispatch actions to the component's own special store? Is there a way to access the store-prop of the <Provider /> for each <SubApp /> (and their child-components)?
例如:我有一些 API 类在从远程服务器获取数据后调用 dispatch.但是由于我无法导入普通"存储，那么处理自定义存储以使它们可用于其他类/文件/服务的最佳方法是什么?
For example: I have some API classes that call dispatch after fetching data from a remote server. But since I can't import the "normal" store, what would be the best way to deal with custom stores to make them available for other classes/files/services?
所以我让它工作了，但我认为这是一种非常肮脏的方式(请注意代码中的 UGLY? 注释):
So I got it working, but I think it's a really dirty way (mind the UGLY? comments inside the code):
提供商:
通过在构造函数中创建商店来为每个实例创建一个商店:
Create a store per instance by creating the store inside the constructor:
export default class OffersGridProvider extends React.Component {
constructor(props) {
super(props)
this.store = createStore(reducers);
}
render() {
return (
<Provider store={this.store}>
<OffersGridContainer offers={this.props.offers} />
</Provider>
);
}
}
容器:
提供者为 this 存储注入了一个 dispatch 方法到我的 OffersGridContainer，我可以使用它来将操作分派到这个实例的存储:
The Provider injects a dispatch method for this store to my OffersGridContainer which I can use to dispatch actions just to the store of this instance:
class OffersGridContainer extends React.Component {
componentDidMount() {
// UGLY???
const { dispatch } = this.props;
let destinationIds = [];
this.props.offers.forEach((offer) => {
offer.to.forEach((destination) => {
destinationIds.push(destination.destination);
});
});
// MORE UGLY???
destinationsApi.getDestinations(dispatch, destinationIds);
}
render() {
return (
<OffersGridLayout destinations={this.props.destinations} />
);
}
}
const mapStateToProps = function(store) {
return {
destinations: store.offersGridState.destinations
};
}
export default connect(mapStateToProps)(OffersGridContainer);
API 方法:
只需使用我作为参数传递给 API 方法的 dispatch 方法:
Just use the dispatch-method that I've passed as argument to my API method:
export function getDestinations(dispatch, ids) {
const url = $('meta[name="site-url"]').attr('content');
const filter = ids.map((id) => {
return `filter[post__in][]=${id}`;
}).join('&');
return axios.get(`${url}/wp-json/wp/v2/destinations?filter[posts_per_page]=-1&${filter}`)
.then(response => {
dispatch(getOffersGridSuccess(response.data));
return response;
});
}
更新 2
刚刚在评论中收到一个关于 mapDispatchToProps 的提示，所以我的 Container 现在看起来像这样:
Update 2
Just received a hint about mapDispatchToProps in the comments, so my Container now looks like this:
class OffersGridContainer extends React.Component {
componentDidMount() {
let destinationIds = [];
this.props.offers.forEach((offer) => {
offer.to.forEach((destination) => {
destinationIds.push(destination.destination);
});
});
this.props.getDestinations(destinationIds);
}
render() {
return (
<OffersGridLayout destinations={this.props.destinations} />
);
}
}
const mapStateToProps = function(store) {
return {
destinations: store.offersGridState.destinations
};
}
const mapDispatchToProps = function(dispatch) {
return {
getDestinations: function(ids) {
return destinationsApi.getDestinations(dispatch, ids);
}
}
}
export default connect(mapStateToProps, mapDispatchToProps)(OffersGridContainer);
更新 3(最终答案)
现在一切正常！代码如下:
Update 3 (the final answer)
Now everything works! Here's to code:
提供商:
export default class OffersGridProvider extends React.Component {
constructor(props) {
super(props)
this.store = createStore(reducers, applyMiddleware(thunk));
}
render() {
return (
<Provider store={this.store}>
<OffersGridContainer offers={this.props.offers} />
</Provider>
);
}
}
容器:
class OffersGridContainer extends React.Component {
componentDidMount() {
const destinationIds = this.props.offers.reduce((acc, offer) => {
return [...acc, ...offer.to.map(d => d.destination)];
}, []);
this.props.getDestinations(destinationIds);
}
render() {
return (
<OffersGridLayout destinations={this.props.destinations} />
);
}
}
const mapStateToProps = function(store) {
return {
destinations: store.offersGridState.destinations
};
}
const mapDispatchToProps = function(dispatch) {
return {
getDestinations: function(ids) {
return dispatch(destinationsApi.getDestinations(ids));
}
}
}
export default connect(mapStateToProps, mapDispatchToProps)(OffersGridContainer);
API 方法:
export function getDestinations(ids) {
return function(dispatch) {
const url = $('meta[name="site-url"]').attr('content');
const filter = ids.map((id) => {
return `filter[post__in][]=${id}`;
}).join('&');
return axios.get(`${url}/wp-json/wp/v2/destinations?filter[posts_per_page]=-1&${filter}`)
.then(response => {
return dispatch(getOffersGridSuccess(response.data));
});
}
}
推荐答案
建议不要直接在组件中调用 api，建议使用 redux-thunk 包.
Instead of making api calls in components directly, I suggest you to use redux-thunk package.
接下来，您应该将 mapDispatchToProps 函数作为第二个参数传递给 connect 函数，以将动作创建器函数注入组件:
Next, you should pass mapDispatchToProps function as second argument to connect function, to inject action creator functions to component:
import { getDestinations } from '../actions';
class OffersGridContainer extends React.Component {
componentDidMount() {
// Tip.
const destinationIds = this.props.offers.reduce((acc, offer) => {
return [...acc, ...offer.to.map(d => d.destination)];
}, []);
// instead `destinationsApi.getDestinations(dispatch, destinationIds)`
// call action creator function
this.props.getDestinations(destinationIds);
}
render() {
return (
<OffersGridLayout destinations={this.props.destinations} />
);
}
}
const mapStateToProps = function(store) {
return {
destinations: store.offersGridState.destinations
};
}
const mapDispatchToProps = function(dispatch) {
return {
// this function will be available in component as
// `this.props.getDestinations`.
getDestinations: function(destinationIds) {
dispatch(getDestinations(destinationIds));
}
};
}
export default connect(mapStateToProps, mapDispatchToProps)(OffersGridContainer);
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