javascript - 如何使用 JavaScript 创建包含多个可选参数的搜索？

Question

我目前拥有的“有效”，但是每个参数都取决于最后一个。我的目标是允许用户使用任意数量的搜索字段来过滤帖子，但我似乎无法理解如何实际执行它。

搜索字段代码:

import React from "react";
import { Input, DropDown } from "../Form";
import "./index.css";

function Sidebar(props) {
  return (
    <div className="sidebar-container">
      <p>Search Posts: {props.carMake}</p>
      <div className="field-wrap">
        <Input
          value={props.carMake}
          onChange={props.handleInputChange}
          name="carMake"
          type="text"
          placeholder="Manufacturer"
        />
      </div>
      <div className="field-wrap">
        <Input
          value={props.carModel}
          onChange={props.handleInputChange}
          disabled={!props.carMake}
          name="carModel"
          type="text"
          placeholder="Model"
        />
      </div>
      <div className="field-wrap">
        <Input
          disabled={!props.carModel || !props.carMake}
          value={props.carYear}
          onChange={props.handleInputChange}
          name="carYear"
          type="text"
          placeholder="Year"
        />
      </div>
      <div className="field-wrap">
        <DropDown
          //disabled={!props.carModel || !props.carMake || !props.carYear}
          value={props.category}
          onChange={props.handleInputChange}
          name="category"
          type="text"
          id="category"
        >
          <option>Select a category...</option>
          <option>Brakes</option>
          <option>Drivetrain</option>
          <option>Engine</option>
          <option>Exhaust</option>
          <option>Exterior</option>
          <option>Intake</option>
          <option>Interior</option>
          <option>Lights</option>
          <option>Suspension</option>
          <option>Wheels & Tires</option>
        </DropDown>
      </div>
    </div>
  );
}

export default Sidebar;

这里是父组件的代码(真正过滤数据的地方):

import React, { Component } from 'react';
import Sidebar from '../../components/Sidebar';
import API from '../../utils/API';
import PostContainer from '../../components/PostContainer';
import { withRouter } from 'react-router';
import axios from 'axios';
import './index.css';

class Posts extends Component {
  constructor(props) {
    super(props);
    this.state = {
      posts: [],
      carMake: '',
      carModel: '',
      carYear: '',
      category: 'Select A Category...'
    };
    this.signal = axios.CancelToken.source();
  }

  componentDidMount() {
    API.getAllPosts({
      cancelToken: this.signal.token
    })
      .then(resp => {
        this.setState({
          posts: resp.data
        });
      })
      .catch(function(error) {
        if (axios.isCancel(error)) {
          console.log('Error: ', error.message);
        } else {
          console.log(error);
        }
      });
  }

  componentWillUnmount() {
    this.signal.cancel('Api is being canceled');
  }

  handleInputChange = event => {
    const { name, value } = event.target;
    this.setState({
      [name]: value
    });
  };

  handleFormSubmit = event => {
    event.preventDefault();
    console.log('Form Submitted');
  };

  render() {
    const { carMake, carModel, carYear, category, posts } = this.state;

    const filterMake = posts.filter(
      post => post.carMake.toLowerCase().indexOf(carMake.toLowerCase()) !== -1
    );
    const filterModel = posts.filter(
      post => post.carModel.toLowerCase().indexOf(carModel.toLowerCase()) !== -1
    );
    const filterYear = posts.filter(
      post => post.carYear.toString().indexOf(carYear.toString()) !== -1
    );
    const filterCategory = posts.filter(
      post => post.category.toLowerCase().indexOf(category.toLowerCase()) !== -1
    );

    return (
      <div className='container-fluid'>
        <div className='row'>
          <div className='col-xl-2 col-lg-3 col-md-4 col-sm-12'>
            <Sidebar
              carMake={carMake}
              carModel={carModel}
              carYear={carYear}
              category={category}
              handleInputChange={this.handleInputChange}
              handleFormSubmit={event => {
                event.preventDefault();
                this.handleFormSubmit(event);
              }}
            />
          </div>
          <div className='col-xl-8 col-lg-7 col-md-6 col-sm-12 offset-md-1'>
            {carMake && carModel && carYear && category
              ? filterCategory.map(post => (
                  <PostContainer post={post} key={post.id} />
                ))
              : carMake && carModel && carYear
              ? filterYear.map(post => (
                  <PostContainer post={post} key={post.id} />
                ))
              : carMake && carModel
              ? filterModel.map(post => (
                  <PostContainer post={post} key={post.id} />
                ))
              : carMake
              ? filterMake.map(post => (
                  <PostContainer post={post} key={post.id} />
                ))
              : posts.map(post => <PostContainer post={post} key={post.id} />)}
          </div>
        </div>
      </div>
    );
  }
}

export default withRouter(Posts);

从 API 返回的数据是对象数组的形式，如下所示:

[{

"id":4,
"title":"1995 Toyota Supra",
"desc":"asdf",
"itemImg":"https://i.imgur.com/zsd7N8M.jpg",
"price":32546,
"carYear":1995,
"carMake":"Toyota",
"carModel":"Supra",
"location":"Phoenix, AZ",
"category":"Exhaust",
"createdAt":"2019-07-09T00:00:46.000Z",
"updatedAt":"2019-07-09T00:00:46.000Z",
"UserId":1

},{

"id":3,
"title":"Trash",
"desc":"sdfasdf",
"itemImg":"https://i.imgur.com/rcyWOQG.jpg",
"price":2345,
"carYear":2009,
"carMake":"Yes",
"carModel":"Ayylmao",
"location":"asdf",
"category":"Drivetrain",
"createdAt":"2019-07-08T23:33:04.000Z",
"updatedAt":"2019-07-08T23:33:04.000Z",
"UserId":1

}]

如上所示，我试图只注释掉下拉菜单的“已禁用”属性，但这会导致它完全停止作为过滤器工作，并返回所有结果，无论选择如何。这是由于我检查每个过滤器的三元运算符困惑造成的。有没有更好的方法可以做到这一点？

Answer 1

尽管@Nina Lisitsinskaya 的回答是正确的，但我不会有一个庞大的 if 列表，并且所有这些都只是通过过滤器连接完成的。

这样添加另一种过滤方式更容易且可读性更强。解决方案虽然相似。

render() {
    const { carMake = '', carModel = '', carYear = '', category = '', posts } = this.state;

    let filtered = [...posts];

        filtered = filtered
            .filter(post => post.carMake.toLowerCase().indexOf(carMake.toLowerCase()) !== -1)
            .filter(post => post.carModel.toLowerCase().indexOf(carModel.toLowerCase()) !== -1)
            .filter(post => post.carYear.toString().indexOf(carYear.toString()) !== -1)
            .filter(post => post.category.toLowerCase().indexOf(category.toLowerCase()) !== -1)

    ...
}

当然之后你想在 JSX 表达式中使用类似于此的 filtered，否则没有任何显示。

  ...

  <div className='col-xl-8 col-lg-7 col-md-6 col-sm-12 offset-md-1'>
    {filtered.map(post => <PostContainer post={post} key={post.id} />)}
  </div>