遍历多个对象的属性

Question

我正在为我的应用开发过滤引擎。现在，我遇到了对象数据之间的迭代问题，我需要检查用户应用的过滤器数组。最终目标是返回匹配一个或多个过滤器选择的对象。

这是我的代码：

const Results = () => {
const [dataStored, setDataStored] = useState([])
const filterArray = useSelector(state => state.filterArray);
const doctors = useSelector(state => state.doctors);

// let doctorsResult = doctors.map(doctor => doctor.indexOf(filterArray) !== -1 )

// let doctorsResult = doctors.map(doctor => {for(let key of Object.keys(doctor)){
//     if (key === 'price' || key === 'gender' || key === 'language'){
//     // setDataStored([...dataStored, doctor[key]])
//     console.log("dataStored",doctor[key])}
//     //  return (dataStored.indexOf(filterArray) !== -1 )

// }})

let doctorsResult = doctors.map(doctor => {
    Object.keys(doctor).forEach((key) => {
        if (key === 'price' || key === 'gender' || key === 'language') {
            setDataStored([...dataStored, doctor[key]])
            console.log("dataStored", dataStored)
        }
        return (dataStored.indexOf(filterArray) !== -1)
    })
})

每个对象都有多个属性，但我只需要检查“价格、性别和语言”值。属性不相等，有些只是字符串，有些是数组。到目前为止，我已经能够使用 for..in 和 forEach 循环通过属性进行迭代。我的问题是，我无法比较和返回任何数据，因为它不是数组，因此 indexOf() 给了我一个错误。当我尝试setDataStored([...dataStored, doctor[key]]) 时，状态进入无限循环。

我对这一切都很陌生。如果有人有更好的方法来实现这一点，我将不胜感激。

编辑：

这是 filterArray 的形状 这是一个动态过滤器，开始是空的，然后被填充

Answer 1

所以你想从两个选择器中获取状态并做一些工作，然后返回结果？这是reselect 的完美问题类型。 Reselect 是一个帮助器，可让您记住有关状态选择器的昂贵计算。

https://github.com/reduxjs/reselect

这对你来说可能是这样的。

$ yarn add reselect

import React from 'react';
import { useSelector } from 'react-redux';
import { createSelector } from 'reselect';

const filterArraySelector = (state) => state.filterArray;
const doctorsSelector = (state) => state.doctors;

const filteredDoctorsSelector = createSelector(doctorsSelector, filterArraySelector, (filterArray, doctors) => {
  return doctors.filter((doctor) => {
    return filterArray.all((key) => {
      // Do some comparison here, return true if you want to include the doctor in the results
      return doctor[key] !== undefined;
    });
  });
});

const Results = () => {
  const filteredDoctors = useSelector(filteredDoctorsSelector);

  return filteredDoctors.map((doctor) => <span>{doctor}</span>);
};

备选方案

无需使用createSelector 来记忆过滤，您可以在每次渲染时简单地过滤医生。像这样：

const Results = () => {
  const filterArray = useSelector((state) => state.filterArray);
  const doctors = useSelector((state) => state.doctors);

  const filteredDoctors = useMemo(
    () =>
      doctors.filter((doctor) => {
        return filterArray.all((key) => {
          // Do some comparison here, return true if you want to return the doctor
          return doctor[key] !== undefined;
        });
      }),
    [doctors, filterArray]
  );

  return filteredDoctors.map((doctor) => <span>{doctor}</span>);
};

更新：

给定一个 filterArray 的值，如下所示：

const filterArray = ['Female', 'English'];

我们可以更新过滤器函数以根据 filterArray 值测试 Objects 值。如果任何属性值与 filterArray 值匹配，那么我们可以将医生包含在生成的 filtersDoctors 列表中。

const Results = () => {
  const filterArray = useSelector((state) => state.filterArray);
  const doctors = useSelector((state) => state.doctors);

  const filteredDoctors = useMemo(() => {
    return doctors.filter((doctor) => {
      return filterArray.some((filter) => {
        return Object.values(doctor).some((value) => value === filter);
      });
    });
  }, [doctors, filterArray]);

  return filteredDoctors.map((doctor) => <span>{doctor}</span>);
};

更新：

聊天讨论后：

const Results = () => {
  const filterArray = useSelector((state) => state.filterArray);
  const doctors = useSelector((state) => state.doctors);

  const filteredDoctors = useMemo(() => {
    return doctors.filter((doctor) => {
      return filterArray.some((filter) => {
        return Object.values(doctor).some((value) => {
          // If the attribute value is an array
          if (Array.isArray(value)) {
            return value.some((value) => value === filter);
          }
          // If the attribute value is an object, get the values from the object
          if (typeof value === 'object') {
            return Object.values(value).some((value) => value === filter);
          }
          // By default, expect the value to be a string
          return value === filter;
        });
      });
    });
  }, [doctors, filterArray]);

  return filteredDoctors.map((doctor) => <span>{doctor}</span>);
};