问题描述
*** 这个问题很简单,我只是写了很多具体的。 ***
我在网上找了几个小时,似乎找不到答案。大多数分页是在您收到来自 API 调用的数据之后,或者用于使用它自己的服务器构建的后端 node.js。
我的问题,我有一个 API 请求,它返回一个包含 500 个 ID 的数组。然后是第二个多 API 调用,循环遍历每个 ID 进行承诺 API 调用。我使用 Promise.all 方法。 完成此请求需要 2-3 分钟。
目前,我做了一个快速过滤器来获取前十个结果,这样它就会显示出来,我可以渲染数据以处理其他事情,比如渲染组件和样式。
我的问题是,我希望能够在 API 调用仍在进行时对数据进行分页。
基本上,Promise.all 发送一个包含 10 个 id(10 个 API 调用)的数组,并不断获取。但是在第一组十个之后,我想开始接收要渲染的数据。
现在,我的过滤方法只能得到十个。或者等待 2-3 分钟让所有 500 个渲染。
这是我的 request.js 文件,(它是我的 App 组件的一部分,为了清楚起见,我只是将其分开)。
import axios from 'axios';
import BottleNeck from 'bottleneck'
const limiter = new BottleNeck({
maxConcurrent: 1,minTime: 333
})
export const Request = (setResults,searchBarType,setLoading) => {
const searchBar = type => {
const obj = {
'new': 'newstories','past': '','comments': 'user','ask': 'askstories','show': 'showstories','jobs': 'jobstories','top': 'topstories','best': 'beststories','user': 'user'
}
return obj[type] ? obj[type] : obj['new'];
}
let type = searchBar(searchBarType)
const getData = () => {
const options = type
const API_URL = `https://hacker-news.firebaseio.com/v0/${options}.json?print=pretty`;
return new Promise((resolve,reject) => {
return resolve(axios.get(API_URL))
})
}
const getIdFromData = (dataId) => {
const API_URL = `https://hacker-news.firebaseio.com/v0/item/${dataId}.json?print=pretty`;
return new Promise((resolve,reject) => {
return resolve(axios.get(API_URL))
})
}
const runAsyncFunctions = async () => {
setLoading(true)
const {data} = await getData()
let firstTen = data.filter((d,i) => i < 10);
Promise.all(
firstTen.map(async (d) => {
const {data} = await limiter.schedule(() => getIdFromData(d))
console.log(data)
return data;
})
)
.then((newresults) => setResults((results) => [...results,...newresults]))
setLoading(false)
// make conditional: check if searchBar type has changed,then clear array of results first
}
runAsyncFunctions()
}
还有帮助,这是我的 App.js 文件
import React,{ useState,useEffect } from 'react';
import './App.css';
import { SearchBar } from './search-bar';
import { Results } from './results';
import { Request } from '../helper/request'
import { Pagination } from './pagination';
function App() {
const [results,setResults] = useState([]);
const [searchBarType,setsearchBarType] = useState('news');
const [loading,setLoading] = useState(false);
const [currentPage,setCurrentPage] = useState(1);
const [resultsPerPage] = useState(3);
// Select search bar button type
const handleClick = (e) => {
const serachBarButtonId = e.target.id;
console.log(serachBarButtonId)
setsearchBarType(serachBarButtonId)
}
// API calls
useEffect(() => {
Request(setResults,setLoading)
},[searchBarType])
// Get current results
const indexOfLastResult = currentPage * resultsPerPage;
const indexOfFirstResult = indexOfLastResult - resultsPerPage;
const currentResults = results.slice(indexOfFirstResult,indexOfLastResult);
// Change page
const paginate = (pageNumber) => setCurrentPage(pageNumber);
return (
<div className="App">
<SearchBar handleClick={handleClick} />
<Results results={currentResults} loading={loading} />
<Pagination resultsPerPage={resultsPerPage} totalResults={results.length} paginate={paginate} />
</div>
);
}
export default App;
我希望它看起来足够通用以遵循指导方针。请问我任何帮助澄清的问题。我花了 8-10 个小时搜索并试图解决这个问题...
解决方法
您可以继续使用您的过滤器,但您必须进行一些更改,对于组件 Pagination 的 totalResults 道具,您必须设置 500 行,以便用户可以选择他想要的页面,因为如果你设置10行,用户可以选择的页面是1,2,3,4,但我们不需要,我们需要把所有的页面1到34页因为我们有 500 个 ID。第二点,我们需要逐页从服务器获取数据,页面大小等于 3 我们需要传递给 Request startIndex 和 lastIndex 给 Request。
请求.js
import axios from 'axios';
import BottleNeck from 'bottleneck'
const limiter = new BottleNeck({
maxConcurrent: 1,minTime: 333
})
export const Request = (setResults,searchBarType,setLoading,startIndex,lastIndex) => {
const searchBar = type => {
const obj = {
'new': 'newstories','past': '','comments': 'user','ask': 'askstories','show': 'showstories','jobs': 'jobstories','top': 'topstories','best': 'beststories','user': 'user'
}
return obj[type] ? obj[type] : obj['new'];
}
let type = searchBar(searchBarType)
const getData = () => {
const options = type
const API_URL = `https://hacker-news.firebaseio.com/v0/${options}.json?print=pretty`;
return new Promise((resolve,reject) => {
return resolve(axios.get(API_URL))
})
}
const getIdFromData = (dataId) => {
const API_URL = `https://hacker-news.firebaseio.com/v0/item/${dataId}.json?print=pretty`;
return new Promise((resolve,reject) => {
return resolve(axios.get(API_URL))
})
}
const runAsyncFunctions = async () => {
setLoading(true)
const {data} = await getData()
let ids = data.slice(firstIndex,lastIndex+1) // we select our ids by index
Promise.all(
ids.map(async (d) => {
const {data} = await limiter.schedule(() => getIdFromData(d))
console.log(data)
return data;
})
)
.then((newresults) => setResults((results) => [...results,...newresults]))
setLoading(false)
// make conditional: check if searchBar type has changed,then clear array of results first
}
runAsyncFunctions()
}
App.js
import React,{ useState,useEffect } from 'react';
import './App.css';
import { SearchBar } from './search-bar';
import { Results } from './results';
import { Request } from '../helper/request'
import { Pagination } from './pagination';
function App() {
const [results,setResults] = useState([]);
const [searchBarType,setsearchBarType] = useState('news');
const [loading,setLoading] = useState(false);
const [currentPage,setCurrentPage] = useState(1);
const [resultsPerPage] = useState(3);
// Select search bar button type
const handleClick = (e) => {
const serachBarButtonId = e.target.id;
console.log(serachBarButtonId)
setsearchBarType(serachBarButtonId)
}
// API calls
useEffect(() => {
Request(setResults,2) //we fetch the first 3 articles
},[searchBarType])
// Change page
const paginate = (pageNumber) => {
// Get current results
const indexOfLastResult = currentPage * resultsPerPage;
const indexOfFirstPost = indexOfLastResult - resultsPerPage;
Request(setResults,indexOfFirstPost,indexOfLastResult) //we fetch the 3 articles of selected page
setCurrentPage(pageNumber);
}
return (
<div className="App">
<SearchBar handleClick={handleClick} />
<Results results={results} loading={loading} />
<Pagination resultsPerPage={resultsPerPage} totalResults={500} paginate={paginate} />
</div>
);
}
export default App;