Reactjs 使用React/Redux和React航路点问题实现无限滚动
我正在努力用我的test React/Redux应用程序实现无限滚动 下面简单介绍一下它的工作原理: 1) 在componentDidMount上,我发送了一个动作,在从API获取100张照片后设置Redux状态。所以我得到了Redux州的照片阵列 2) 我实现了react航路点,因此当您滚动到这些照片的底部时,它会触发一个方法,该方法将发送另一个操作,以获取更多照片并将其“附加”到照片数组中,然后 据我所知,状态已更改,因此redux正在启动setState,组件将完全重新绘制,因此我需要再次开始滚动,但现在它有200张照片。当我再次到达航路点时,一切都再次发生,组件完全重新启动,我现在需要从顶部滚动300张照片 当然,这不是我想要的工作方式 没有Redux的react航路点的简单示例如下:Reactjs 使用React/Redux和React航路点问题实现无限滚动,reactjs,redux,infinite-scroll,Reactjs,Redux,Infinite Scroll,我正在努力用我的test React/Redux应用程序实现无限滚动 下面简单介绍一下它的工作原理: 1) 在componentDidMount上,我发送了一个动作,在从API获取100张照片后设置Redux状态。所以我得到了Redux州的照片阵列 2) 我实现了react航路点,因此当您滚动到这些照片的底部时,它会触发一个方法,该方法将发送另一个操作,以获取更多照片并将其“附加”到照片数组中,然后 据我所知,状态已更改,因此redux正在启动setState,组件将完全重新绘制,因此我需要再次
export default function myReducer(state = initialState, action) {
switch (action.type) {
case types.RECEIVE_PHOTOS:
return {
...state,
photos: [
...state.photos,
...action.photos,
],
};
...
1) 获取第一张照片并将组件设置为初始状态
2) 滚动到航路点后,它触发一个方法,该方法向api发出另一个请求,构造新照片数组(附加新获取的照片),并使用新照片数组(!)调用setState
它是有效的。组件没有完全重新渲染。滚动位置保持不变,新项目显示在航路点下方
所以问题是-我遇到的问题是Redux状态管理问题,还是我实施Redux还原程序/操作不正确,或者
为什么在中设置组件状态(无重绘)会按照我想要的方式工作(无重绘整个组件)
谢谢你的帮助!谢谢大家!
减速器
import { combineReducers } from 'redux';
const data = (state = {}, action) => {
if (action.type === 'PHOTOS_FETCH_DATA_SUCCESS') {
const photos = state.photos ?
[...state.photos, ...action.data.photo] :
action.data.photo;
return {
photos,
numPages: action.data.pages,
loadedAt: (new Date()).toISOString(),
};
}
return state;
};
const photosHasErrored = (state = false, action) => {
switch (action.type) {
case 'PHOTOS_HAS_ERRORED':
return action.hasErrored;
default:
return state;
}
};
const photosIsLoading = (state = false, action) => {
switch (action.type) {
case 'PHOTOS_IS_LOADING':
return action.isLoading;
default:
return state;
}
};
const queryOptionsIntitial = {
taste: 0,
page: 1,
sortBy: 'interestingness-asc',
};
const queryOptions = (state = queryOptionsIntitial, action) => {
switch (action.type) {
case 'SET_TASTE':
return Object.assign({}, state, {
taste: action.taste,
});
case 'SET_SORTBY':
return Object.assign({}, state, {
sortBy: action.sortBy,
});
case 'SET_QUERY_OPTIONS':
return Object.assign({}, state, {
taste: action.taste,
page: action.page,
sortBy: action.sortBy,
});
default:
return state;
}
};
const reducers = combineReducers({
data,
photosHasErrored,
photosIsLoading,
queryOptions,
});
export default reducers;
import tastes from '../tastes';
// Action creators
export const photosHasErrored = bool => ({
type: 'PHOTOS_HAS_ERRORED',
hasErrored: bool,
});
export const photosIsLoading = bool => ({
type: 'PHOTOS_IS_LOADING',
isLoading: bool,
});
export const photosFetchDataSuccess = data => ({
type: 'PHOTOS_FETCH_DATA_SUCCESS',
data,
});
export const setQueryOptions = (taste = 0, page, sortBy = 'interestingness-asc') => ({
type: 'SET_QUERY_OPTIONS',
taste,
page,
sortBy,
});
export const photosFetchData = (taste = 0, page = 1, sort = 'interestingness-asc', num = 500) => (dispatch) => {
dispatch(photosIsLoading(true));
dispatch(setQueryOptions(taste, page, sort));
const apiKey = '091af22a3063bac9bfd2e61147692ecd';
const url = `https://api.flickr.com/services/rest/?api_key=${apiKey}&method=flickr.photos.search&format=json&nojsoncallback=1&safe_search=1&content_type=1&per_page=${num}&page=${page}&sort=${sort}&text=${tastes[taste].keywords}`;
// console.log(url);
fetch(url)
.then((response) => {
if (!response.ok) {
throw Error(response.statusText);
}
dispatch(photosIsLoading(false));
return response;
})
.then(response => response.json())
.then((data) => {
// console.log('vvvvv', data.photos);
dispatch(photosFetchDataSuccess(data.photos));
})
.catch(() => dispatch(photosHasErrored(true)));
};
动作创作者
import { combineReducers } from 'redux';
const data = (state = {}, action) => {
if (action.type === 'PHOTOS_FETCH_DATA_SUCCESS') {
const photos = state.photos ?
[...state.photos, ...action.data.photo] :
action.data.photo;
return {
photos,
numPages: action.data.pages,
loadedAt: (new Date()).toISOString(),
};
}
return state;
};
const photosHasErrored = (state = false, action) => {
switch (action.type) {
case 'PHOTOS_HAS_ERRORED':
return action.hasErrored;
default:
return state;
}
};
const photosIsLoading = (state = false, action) => {
switch (action.type) {
case 'PHOTOS_IS_LOADING':
return action.isLoading;
default:
return state;
}
};
const queryOptionsIntitial = {
taste: 0,
page: 1,
sortBy: 'interestingness-asc',
};
const queryOptions = (state = queryOptionsIntitial, action) => {
switch (action.type) {
case 'SET_TASTE':
return Object.assign({}, state, {
taste: action.taste,
});
case 'SET_SORTBY':
return Object.assign({}, state, {
sortBy: action.sortBy,
});
case 'SET_QUERY_OPTIONS':
return Object.assign({}, state, {
taste: action.taste,
page: action.page,
sortBy: action.sortBy,
});
default:
return state;
}
};
const reducers = combineReducers({
data,
photosHasErrored,
photosIsLoading,
queryOptions,
});
export default reducers;
import tastes from '../tastes';
// Action creators
export const photosHasErrored = bool => ({
type: 'PHOTOS_HAS_ERRORED',
hasErrored: bool,
});
export const photosIsLoading = bool => ({
type: 'PHOTOS_IS_LOADING',
isLoading: bool,
});
export const photosFetchDataSuccess = data => ({
type: 'PHOTOS_FETCH_DATA_SUCCESS',
data,
});
export const setQueryOptions = (taste = 0, page, sortBy = 'interestingness-asc') => ({
type: 'SET_QUERY_OPTIONS',
taste,
page,
sortBy,
});
export const photosFetchData = (taste = 0, page = 1, sort = 'interestingness-asc', num = 500) => (dispatch) => {
dispatch(photosIsLoading(true));
dispatch(setQueryOptions(taste, page, sort));
const apiKey = '091af22a3063bac9bfd2e61147692ecd';
const url = `https://api.flickr.com/services/rest/?api_key=${apiKey}&method=flickr.photos.search&format=json&nojsoncallback=1&safe_search=1&content_type=1&per_page=${num}&page=${page}&sort=${sort}&text=${tastes[taste].keywords}`;
// console.log(url);
fetch(url)
.then((response) => {
if (!response.ok) {
throw Error(response.statusText);
}
dispatch(photosIsLoading(false));
return response;
})
.then(response => response.json())
.then((data) => {
// console.log('vvvvv', data.photos);
dispatch(photosFetchDataSuccess(data.photos));
})
.catch(() => dispatch(photosHasErrored(true)));
};
我还包括了渲染照片的主要组件,因为我认为这可能与我将此组件“连接”到Redux存储的事实有关
import React from 'react';
import injectSheet from 'react-jss';
import { connect } from 'react-redux';
import Waypoint from 'react-waypoint';
import Photo from '../Photo';
import { photosFetchData } from '../../actions';
import styles from './styles';
class Page extends React.Component {
loadMore = () => {
const { options, fetchData } = this.props;
fetchData(options.taste, options.page + 1, options.sortBy);
}
render() {
const { classes, isLoading, isErrored, data } = this.props;
const taste = 0;
const uniqueUsers = [];
const photos = [];
if (data.photos && data.photos.length > 0) {
data.photos.forEach((photo) => {
if (uniqueUsers.indexOf(photo.owner) === -1) {
uniqueUsers.push(photo.owner);
photos.push(photo);
}
});
}
return (
<div className={classes.wrap}>
<main className={classes.page}>
{!isLoading && !isErrored && photos.length > 0 &&
photos.map(photo =>
(<Photo
key={photo.id}
taste={taste}
id={photo.id}
farm={photo.farm}
secret={photo.secret}
server={photo.server}
owner={photo.owner}
/>))
}
</main>
{!isLoading && !isErrored && photos.length > 0 && <div className={classes.wp}><Waypoint onEnter={() => this.loadMore()} /></div>}
{!isLoading && !isErrored && photos.length > 0 && <div className={classes.wp}>Loading...</div>}
</div>
);
}
}
const mapStateToProps = state => ({
data: state.data,
options: state.queryOptions,
hasErrored: state.photosHasErrored,
isLoading: state.photosIsLoading,
});
const mapDispatchToProps = dispatch => ({
fetchData: (taste, page, sort) => dispatch(photosFetchData(taste, page, sort)),
});
const withStore = connect(mapStateToProps, mapDispatchToProps)(Page);
export default injectSheet(styles)(withStore);
从“React”导入React;
从“react jss”导入表单;
从'react redux'导入{connect};
从“反应航路点”导入航路点;
从“../Photo”导入照片;
从“../../actions”导入{photofetchdata};
从“./styles”导入样式;
类页扩展了React.Component{
加载更多=()=>{
const{options,fetchData}=this.props;
fetchData(options.taste,options.page+1,options.sortBy);
}
render(){
const{classes,isLoading,isErrored,data}=this.props;
常量味觉=0;
const uniqueUsers=[];
常量照片=[];
如果(data.photos&&data.photos.length>0){
data.photos.forEach((照片)=>{
if(uniqueUsers.indexOf(photo.owner)=-1){
uniqueUsers.push(photo.owner);
照片。推送(照片);
}
});
}
返回(
{!isLoading&&!iErrored&&photos.length>0&&
photos.map(照片=>
())
}
{!isLoading&&!iErrored&&photos.length>0&&this.loadMore()}/>}
{!isLoading&&!isErrored&&photos.length>0&&Loading…}
);
}
}
常量mapStateToProps=状态=>({
数据:state.data,
选项:state.queryOptions,
haserroed:state.photoshaserroed,
isLoading:state.photosIsLoading,
});
const mapDispatchToProps=调度=>({
fetchData:(味道、页面、排序)=>dispatch(PhotoFetchData(味道、页面、排序)),
});
const withStore=connect(mapStateToProps、mapDispatchToProps)(第页);
导出默认图纸(样式)(带存储);
回答Eric Na
state.photos是一个对象,我只是检查它是否存在于状态中。对不起,在我的例子中,我只是试图简化事情
action.data.photo肯定是一个数组。Api给它起了这样的名字,我没有想过要给它改名
我提供了一些来自react开发工具的图片
所以我想说的是,这些照片是被提取和附加的,但它仍然会触发组件的整个重新渲染…EDIT2
尝试对整个uniqueUsers
部分进行注释(稍后让我们担心用户的唯一性)
而不是
photos.map(photo =>
(<Photo ..
编辑 你能确定它是
action.data.photo
,而不是action.data.photos
,甚至只是action.data
?您可以尝试将数据记录到控制台吗
而且
在这里,state.photos
将始终计算为true
-y值,即使它是一个空数组。你可以把它改成
state.photos.length ? .. : ..
在没有看到你如何在
还原器
和操作
中更新照片
的情况下很难判断,但我怀疑这是Redux如何管理状态的问题
当您从ajax请求中获得新照片时,新照片应该附加到存储区中照片数组的末尾
例如,如果当前Reduxstore
中的photos:[,…]
,并且action
中的新照片是photos:[,…]
,则store
中的照片应如下更新:
export default function myReducer(state = initialState, action) {
switch (action.type) {
case types.RECEIVE_PHOTOS:
return {
...state,
photos: [
...state.photos,
...action.photos,
],
};
...
我想我看到了问题所在
在您的组件中检查
{!isLoading && !isErrored && photos.length > 0 &&
photos.map(photo =>
(<Photo
key={photo.id}
taste={taste}
id={photo.id}
farm={photo.farm}
secret={photo.secret}
server={photo.server}
owner={photo.owner}
/>))
}
{!isLoading&&!iErrored&&photos.length>0&&
photos.map(照片=>
())
}
一旦发出另一个api请求,在action creator中将isLoading
设置为true
。这告诉react删除整个照片组件,然后将其设置为false
后,react将再次显示新照片
您需要在底部添加一个加载程序,而不是在抓取后删除整个照片组件,然后再次进行渲染。您可以发布代码(尤其是减速机和组件),以便我们能够看到哪里出了问题吗?刚刚添加。谢谢谢谢我发布了我的减速机代码。我想我是按照你说的做的,但它仍然工作相同
{!isLoading && !isErrored && photos.length > 0 &&
photos.map(photo =>
(<Photo
key={photo.id}
taste={taste}
id={photo.id}
farm={photo.farm}
secret={photo.secret}
server={photo.server}
owner={photo.owner}
/>))
}