我正在构建一个React应用程序,其中用户输入搜索词,后端提供json数组。在结果页面上,我正在尝试实施分面搜索,因此我没有几个过滤器。我正在根据用户选择的复选框过滤获取的结果。这是UI。
这是我的搜索结果页面的js文件。
import React from 'react';
import NavigationBar from './NavigationBar';
import SearchPageResultsStyle from "../assets/css/SearchResultsPage.css"
import Pagination from './Pagination';
class SearchResultsPage extends React.Component{
constructor(props) {
super(props);
this.state = {
results: this.props.location.state.data.results,
keyword: this.props.location.state.data.keyword,
pageOfItems: [],
cities: {
'New York City (NYC)': false,
'Delhi': false,
'Bangkok': false,
'Paris': false,
'Mexico City': false
},
topics: {
'Environment': false,
'Crime': false,
'Politics': false,
'Social Unrest': false,
'Infrastructure': false
},
languages: {
'Hindi': false,
'English': false,
'Thai': false,
'French': false,
'Spanish': false
}
};
this.onChangePage = this.onChangePage.bind(this);
this.onCityChange = this.onCityChange.bind(this);
}
componentDidUpdate(prevProps, prevState) {
if (prevState !== this.state) {
console.log(this.state.cities);
const filteredCities = [];
for (let key in this.state.cities) {
if (this.state.cities[key] === true) {
filteredCities.push(key)
}
}
console.log(filteredCities);
const filteredResults = [];
this.state.results.forEach((result) => {
for (let i = 0; i < filteredCities.length; i++) {
if (result.city === filteredCities[i]) {
filteredResults.push(result)
}
}
})
console.log("fileterdPageOfItems", filteredResults)
this.updatePageOfItems(filteredResults)
}
}
// Function to filter the search results based on user chosen filters
updatePageOfItems(filteredResults) {
this.setState({
results: filteredResults
})
}
onChangePage(pageOfItems) {
// update local state with new page of items
this.setState({pageOfItems});
}
// setting each city in cities object (city chechboxes which are clicked on UI) to true
onCityChange(e) {
const val = e.target.checked;
const name = e.target.name;
let updatedCities = Object.assign({},this.state.cities,{[name]: val});
this.setState({
cities: updatedCities,
})
}
// rendering checkboxes for cities
renderCity() {
const cities = ['New York City (NYC)','Delhi','Bangkok','Paris','Mexico City']
return cities.map((city,i) => {
return (
<div>
<label key={i}>
{city}
<input
type="checkbox"
name={city}
onChange={this.onCityChange}
value={this.state.cities[city]}/>
</label>
</div>
)
})
}
render() {
const renderItems = this.state.pageOfItems.map((item, index) => {
return (
<div>
<h3 style={{color: '#1a0dab'}} key={index}>{item.text}</h3>
<a href={'https://google.com'} key={index}>{item.tweetUrl}</a>
<br/>
<p><span style={{fontWeight:'bold', textColor:'#6a6a6a'}} key={index}>topic: </span>{item.topic}</p>
<p><span style={{fontWeight:'bold', textColor:'#6a6a6a'}} key={index}>city: </span>{item.city}</p>
<p><span style={{fontWeight:'bold', textColor:'#6a6a6a'}} key={index}>lang: </span>{item.lang}</p>
<p><span style={{fontWeight:'bold', textColor:'#6a6a6a'}} key={index}>Hashtags: </span></p>
<hr/>
</div>
)
});
return (
<div>
<NavigationBar/>
<h4 style={{textAlign:'center', color:'#1a0dab'}}>Showing search results for <span style={{fontWeight:'bold', fontStyle:'Italic'}}>'{this.state.keyword}'</span></h4>
<hr/>
<div className={'wrap'} style={SearchPageResultsStyle}>
<div className={'fleft'}>
<h4>City</h4>
{this.renderCity()}
<hr/>
<h4>Topics</h4>
<hr/>
<h4>Language</h4>
<hr/>
</div>
<div className={'fcenter'}>
{renderItems}
<Pagination items={this.state.results} onChangePage={this.onChangePage}/>
</div>
<div className={'fright'}></div>
</div>
</div>
)
}
}
export default SearchResultsPage;
每当用户单击特定的复选框时,我都会将状态中的城市更新为true,然后根据阵列filteredCities
中的城市过滤(从后端)提取的结果,并进行收集过滤后的结果放入数组filteredResults
中,然后将该数组传递给函数updatePageOfItems
来更改状态,以便可以重新渲染过滤后的结果。但是,当我调用函数updatePageOfItems
时,应用程序进入了无限循环。
解决此问题的方法是什么?我是第一次来面对这个问题的新手。
答案 0 :(得分:0)
我能够解决此问题,而不是在函数componentDidUpdate
中过滤结果,而是在setState
函数内的onCityChange
的回调函数中进行了操作。
onCityChange(e) {
const val = e.target.checked;
const name = e.target.name;
let updatedCities = Object.assign({},this.state.cities,{[name]: val});
this.setState({
cities: updatedCities,
},function () {
const filteredCities = [];
for (let key in this.state.cities) {
if (this.state.cities[key] === true) {
filteredCities.push(key)
}
}
console.log("filteredCities", filteredCities);
const filteredResults = [];
this.state.results.forEach((result) => {
for (let i = 0; i < filteredCities.length; i++) {
if (result.city === filteredCities[i]) {
filteredResults.push(result)
}
}
})
this.setState({
results: filteredResults
},function () {
console.log(this.state.results)
})
})
}