问题描述
我正在学习本教程 → https://blog.logrocket.com/pagination-in-graphql-with-prisma-the-right-way/
我尝试像这样实现它:
import React from 'react'
import { useQuery } from 'urql'
import { Card } from '../components/index'
import {
GET_ALL_ACQUISITIONS,GET_ACQUISITIONS_BY_PRICE,} from '../graphql/index'
export const AcquisitionList = ({
minPrice,maxPrice,undisclosed,sortByDescPrice,sortByAscStartupName,}) => {
const [skip,setSkip] = React.useState(0)
const [result,reexecuteQuery] = useQuery({
query: GET_ACQUISITIONS_BY_PRICE,variables: {
minPrice,skip,take: 20,},})
const { data,fetching,error } = result
if (fetching) return <p className="mt-10 text-4xl text-center">Loading...</p>
if (error)
return (
<p className="mt-10 text-4xl text-center">Oh no... {error.message}</p>
)
return (
<>
<div className="flex flex-wrap justify-center mt-10">
{data.getAcquisitionsByPrice.map((startup,i) => {
return <Card key={i} startup={startup} index={i} />
})}
</div>
<div className="flex justify-center">
<button onClick={() => setSkip(skip + 20)}>Load More...</button>
</div>
</>
)
}
但是当我点击 Load More...
按钮时,我失去了之前的所有状态。它还用 Loading
替换了整个 UI,因为我的 if (fetching)
条件位于显示卡的顶部。
如何在使用新查询调用 prisma 时保留以前的状态,以便显示所有显示卡?
所以第一次,我有 20 张卡,第二次加载时应该有 40 张卡等等......
目前,它一次只显示 20 张卡片,如果我有 PrevIoUs
和 Next
按钮,这很好,但我希望它通过单击按钮像 Instagram 一样显示。
解决方法
必须将结果存储在单独的本地状态中,并且在每个新的查询结果中,只需添加:
import React from 'react'
import { useQuery } from 'urql'
import { Card } from '../components/index'
import {
GET_ALL_ACQUISITIONS,GET_ACQUISITIONS_BY_PRICE,} from '../graphql/index'
const Template = ({ children }) => (
<p className="mt-10 text-4xl text-center">{children}</p>
)
export const AcquisitionList = ({
minPrice,maxPrice,undisclosed,sortByDescPrice,sortByAscStartupName,}) => {
const [acq,setAcq] = React.useState([])
const [skip,setSkip] = React.useState(0)
const [result,reexecuteQuery] = useQuery({
query: GET_ACQUISITIONS_BY_PRICE,variables: {
minPrice,skip,take: 20,},})
const { data,fetching,error } = result
React.useEffect(() => {
setAcq([...acq,...data])
},[data])
if (fetching && !data) return <Template>Loading...</Template>
if (error && !data) return <Template>Oh no... {error.message}</Template>
return (
<>
{data.getAcquisitionsByPrice.length > 0 && (
<div className="flex flex-wrap justify-center mt-10">
{acq.length > 0 &&
acq.getAcquisitionsByPrice.map((startup,i) => {
return <Card key={i} startup={startup} index={i} />
})}
</div>
)}
{fetching && <Template>Loading...</Template>}
{error && <Template>Oh no... {error.message}</Template>}
{data.getAcquisitionsByPrice.length !== 0 && (
<div className="flex justify-center">
<button
className="inline-flex items-center px-4 py-2 mt-16 text-sm font-medium text-white border border-transparent rounded-md shadow-sm select-none transform hover:-translate-y-0.5 transition-all duration-150 bg-gradient-to-br from-indigo-600 hover:bg-gradient-to-br hover:from-indigo-700 focus:ring-indigo-500 focus:outline-none focus:ring-2 focus:ring-offset-2 hover:shadow-lg"
onClick={() => setSkip(skip + 20)}
>
<svg
className="w-6 h-6 text-white"
fill="none"
viewBox="0 0 24 24"
stroke="currentColor"
>
<path
strokeLinecap="round"
strokeLinejoin="round"
strokeWidth="2"
d="M15 13l-3 3m0 0l-3-3m3 3V8m0 13a9 9 0 110-18 9 9 0 010 18z"
></path>
</svg>
<span className="ml-2">Load More...</span>
</button>
</div>
)}
</>
)
}