javascript - 如何从对象中递归地删除子对象？

Question

我正在研究解决方案

我已经创建了基本的树型表格，每当用户点击展开时，与点击行相关的数据将根据行数据显示在其下方

我已经实现了展开/折叠到 N 层嵌套的基本功能。

但我只遇到一个问题，所以基本上所有行都有基于具有多个值的数组的条件展开按钮

假设它是一个包含 3 个条目 county,city,state 的拆分数组

默认加载的数据将从 api 获取，现在我必须检查数组是否有可用的拆分!如果是，我会让展开按钮可见

考虑这个场景

const split = ["country","city","state"]

这是 Ui 的样子

+ Data_1
+ Data_2

单击按钮 + 新数据表行将根据下一个可用拆分呈现，在我们的例子中它是国家/地区，因此视觉表示就像

- Data_1
   Country_1
   Country_2
+ Data_2

这里的国家/地区没有展开按钮，因为用户还没有添加下一个拆分，让我们添加城市，并假设用户点击了 Country_1，这样数据会像

    - Data_1
       - Country_1
           City_1
           City_2
       + Country_2
    + Data_2

我的解决方案工作正常，直到这个级别现在假设用户已经从拆分中删除了国家和城市的所有节点应该删除并且 - data_1 的图标应该更改为 +

这是我的代码

import React, {useState, useEffect, useRef, Fragment} from "react";
  import _ from "lodash";
  import axios from "axios";

  class TableRowData extends React.Component {
    state = {
      showIcon: false,
      selection: [],
      data: [],
      splitOption: ["campid"]
    };
    constructor(props) {
      super(props);
    }

    componentDidMount() {
      const checkIfSplitExistOnMount = (currentSplit) => {
        const i = _.findIndex(this.state.splitOption, function(el) {
          return el === currentSplit;
        });

        if (this.state.splitOption[i + 1]) {
          return this.state.splitOption[i + 1];
        } else {
            return null;
        }
      }
      const getReportData = () => {
        axios.get("https://jsonplaceholder.typicode.com/users?_start=0&_limit=1").then((res) => {
          const rowData = res.data.map((row) => {
            row.name = this.state.splitOption[0];
            row.isExpanded = false;
            row.currentSplit = this.state.splitOption[0];
            row.nextSplit = checkIfSplitExistOnMount(this.state.splitOption[0])
            row.parentId = 0;
            row.isVisble = true;
            //console.log(row)
            return row;
          });
          this.setState({
            data: rowData
          }, () => { //console.log(this.state.data)
          });
        });
      }
      getReportData()
    }

    render() {
      // update state function
      const updateState = () => {
        this.setState({
          data: [...this.state.data],
          splitOption: [...this.state.splitOption],
          selection: [...this.state.selection],
        }, () => {})
      }

      // recusively update parent and child
      const recursion = (obj) => {
         let row = obj;
         row.isExpanded = row.isExpanded;
         row.currentSplit = row.currentSplit;
         row.nextSplit = checkIfSplitExist(row.currentSplit)

         if (row.children && row.children.length > 0) { // check if has children
            row.children.forEach(v => { // if has children do the same recursion for every children
              recursion(v);
            });
         }
         return row; // return final new object
       }

       const recursionDel = (obj,split) => {
           var row = obj;
           row.currentSplit = row.currentSplit;
           row.nextSplit = checkIfSplitExist(row.currentSplit)
           if (row.children && row.children.length > 0) { // check if has children
             row.children.forEach(v => { // if has children do the same recursion for every children
               recursionDel(v);
             });
          }
          return row; // return final new object
        }

      // function to check if next split is there or not if there than return nextsplit
      const checkIfSplitExist = (currentSplit) => {
        const i = _.findIndex(this.state.splitOption, function(el) {
          return el === currentSplit;
        });
        if(i !== -1) {
          if (this.state.splitOption[i + 1]) {
            return this.state.splitOption[i + 1];
           } else {
            return null;
          }
        }

      }

      // recursive update whenever split added
      const recursiveUpdate = (data) => {
        const prevData = [...data];
        return prevData.map((row) => {
          const updatedData =  recursion(row);
          return row;
        });
      }

      // function to delete child and parent node recursively
      const recursiveDelete = (data,split) => {
        const prevData = [...data];
        return prevData.map((row) => {
          const data =  recursionDel(row,split);
          return row;
        });
      }

      const addNewSplit = (split) => {
        const i = _.findIndex(this.state.splitOption, function(el) {
          return el === split;
        });
        if(i === -1) {
            this.setState(
              {
                splitOption:[...this.state.splitOption,split]
              },
              ()=>{
                var rowData = recursiveUpdate(this.state.data)
                this.setState({data:rowData})
              }
          );
        } else {
          const prevData = [...this.state.splitOption];
          var index = prevData.indexOf(split);
          prevData.splice(index,1)
          if(index!==-1) {
            this.setState(
                {
                    splitOption:prevData
                },
                ()=> {
                  var rowData = recursiveDelete(this.state.data,split)
                  this.setState({data:rowData})
                }
              )
          }
        }

      }

      // add lazyload expand data
      const ExpandableTableRow = ({rows}) => {

        const expandRow = (row) => {
          row.children = [
            {
              id: "_" + Math.random().toString(36).substr(2, 5),
              name: row.id + "_" + row.nextSplit,
              isExpanded: false,
              parentId: row.id,
              currentSplit: row.nextSplit,
              nextSplit: checkIfSplitExist(row.nextSplit),
              isVisble:true
            }, {
              id: "_" + Math.random().toString(36).substr(2, 5),
              name: row.id + "_" + row.nextSplit,
              isExpanded: false,
              parentId: row.id,
              currentSplit: row.nextSplit,
              nextSplit: checkIfSplitExist(row.nextSplit),
              isVisble:true
            }
          ];
          row.isExpanded = true;
          updateState();
        };

        // call whenever - click
        const collapseRow = (row) => {
          delete row.children;
          row.isExpanded = false;
          updateState();
        };

        // toggle
        const ExpandCollapsToggle = ({row, expandRow, collapseRow}) => {
          // display +/- only if nextsplit is not undefined or null
          if (row.nextSplit) {
            if (row.isExpanded === true) {
              return (<button type="button" onClick={() => collapseRow(row)}>
                -
              </button>);
            } else {
              return (<button type="button" onClick={() => expandRow(row)}>
                +
              </button>);
            }
          } else {
            return null;
          }
        };



        if (rows) {
          return rows.map((row) => {
          //  if(!_.isEmpty(row)) {
              return (<Fragment key={row.id}>
                <tr key={row.id}>
                  <td>
                    <ExpandCollapsToggle row={row} expandRow={expandRow} collapseRow={collapseRow}/>{" "}
                    {row.split}
                    - {row.id}
                  </td>
                  <td>{row.name}</td>
                </tr>
                <ExpandableTableRow rows={row.children}/>
              </Fragment>);
          //  }

          });
        } else {
          return null;
        }
      };

      const splitData = this.state.splitOption.map((ob) => {
        return (<Fragment key={ob}><span>{ob}</span> > </Fragment>)
      })

      if (this.state.data) {
        return (
          <Fragment>
            {splitData} <br/>
            <button onClick = {()=>addNewSplit("name")}>camp name</button>
            <button onClick = {()=>addNewSplit("os")}>os</button>
            <button onClick = {()=>addNewSplit("country")}>country</button>
          <ExpandableTableRow rows={this.state.data} />
        </Fragment>
        );
      } else {
        return null;
      }
    }
  }

  export default TableRowData;

我还创建了 codesandbox.io 示例 - Link

这是你如何使用 ui 来复制场景

• 首先点击营地名称，会出现展开图标
• 现在想展开就展开，可以看到数据按照split under
• 现在再添加一个拆分操作系统或国家/地区，您可以看到带有第二级行的展开图标
• 下一步是删除“营地名称”，这是营地名称被删除时的问题，表格应该根据可用的拆分重新呈现，在我们的例子中，用户的所有行都应该被删除，+ 图标必须在那里，我们有下一个拆分操作系统或国家/地区可用，我使用默认拆分 ID，它将始终存在

Answer 1

import React, { useState, useEffect, useRef, Fragment } from "react";
import axios from "axios";

const test_data = [{
  "id":1,
    "name":"Leanne Graham",
    "username":"Bret",
    "email":"Sincere@april.biz",
    "address":{
      "street":"Kulas Light",
      "suite":"Apt. 556",
      "city":"Gwenborough",
      "zipcode":"92998-3874",
      "geo":{
        "lat":"-37.3159",
        "lng":"81.1496"
      }
    },
    "phone":"1-770-736-8031 x56442",
    "website":"hildegard.org",
    "company":{
      "name":"Romaguera-Crona",
      "catchPhrase":"Multi-layered client-server neural-net",
      "bs":"harness real-time e-markets"
    }
}];

class TableRowData extends React.Component {

  constructor(props) {
    super(props);

    this.state = {
      showIcon: false,
      selection: [],
      data: [],
      splitOption: ["campid"]
    };
  }

  // function to check if next split is there or not if there than return nextsplit
  checkIfSplitExist = (currentSplit) => {
    const i = this.state.splitOption.indexOf(currentSplit);

    if (i > -1 && this.state.splitOption[i + 1]) {
      return this.state.splitOption[i + 1];
    }
    return null;
  }

  getReportData = () => {
    // axios.get("https://jsonplaceholder.typicode.com/users?_start=0&_limit=1").then(({data}) => {
      this.setState({
        data: test_data.map((row) => {
        row.name = this.state.splitOption[0];
        row.isExpanded = false;
        row.currentSplit = this.state.splitOption[0];
        row.nextSplit = this.checkIfSplitExist(this.state.splitOption[0])
        row.parentId = 0;
        row.isVisble = true;
        console.log(row)
        return row;
      })
      });
    // });
  }
  
  componentDidMount() {
    this.getReportData()
  }

  render() {
    // update state function
    const updateState = () => {
      this.setState({
        data: [...this.state.data],
        splitOption: [...this.state.splitOption],
        selection: [...this.state.selection],
      }, () => { })
    }

    const recursionUpdateAndDeleteRow = (parentRow, childRow, split, index = 0) => {
      childRow.children && childRow.children.forEach((r) => {
        recursionUpdateAndDeleteRow(childRow, r, split, index + 1);
      });

      if (parentRow && split.indexOf(childRow.currentSplit) == -1) {
        delete parentRow.children;
      }

      childRow.currentSplit = split[index];
      childRow.nextSplit = split[index + 1] || null;
      if (!childRow.children) {
        childRow.isExpanded = false;
      }
    }

    const recursionUpdateAndDeleteRows = (rows, split) => {
      const _copy = [...rows];
      _copy.forEach((row) => {
        recursionUpdateAndDeleteRow(null, row, split);
      });
      return _copy;
    }

    const toggleSplit = (split) => {
      const index = this.state.splitOption.indexOf(split);
      let currentSplitOptions = [...this.state.splitOption];
      if (index > -1) {
        currentSplitOptions.splice(index, 1)
      }
      else {
        currentSplitOptions.push(split);
      }

      const _data = recursionUpdateAndDeleteRows(this.state.data, currentSplitOptions);

      this.setState({
        splitOption: currentSplitOptions,
        data: _data
      })
    }

    // add lazyload expand data
    const ExpandableTableRow = ({ rows }) => {

      const expandRow = (row) => {
        row.children = [
          {
            id: "_" + Math.random().toString(36).substr(2, 5),
            name: row.id + "_" + row.nextSplit,
            isExpanded: false,
            parentId: row.id,
            currentSplit: row.nextSplit,
            nextSplit: this.checkIfSplitExist(row.nextSplit),
            isVisble: true
          }, {
            id: "_" + Math.random().toString(36).substr(2, 5),
            name: row.id + "_" + row.nextSplit,
            isExpanded: false,
            parentId: row.id,
            currentSplit: row.nextSplit,
            nextSplit: this.checkIfSplitExist(row.nextSplit),
            isVisble: true
          }
        ];
        row.isExpanded = true;
        updateState();
      };

      // call whenever - click
      const collapseRow = (row) => {
        delete row.children;
        row.isExpanded = false;
        updateState();
      };

      // toggle
      const ExpandCollapsToggle = ({ row }) => {
        // display +/- only if nextsplit is not undefined or null
        if (row.nextSplit) {
          if (row.isExpanded) {
            return (
              <button type="button" onClick={() => collapseRow(row)}>
                -
              </button>
            );
          }
          return (
            <button type="button" onClick={() => expandRow(row)}>
              +
            </button>
          );
        }
        return null;
      };

      if (rows) {
        return rows.map((row) => {
          return (
            <Fragment key={row.id}>
            <tr key={row.id}>
              <td>
                <ExpandCollapsToggle
                  row={row}
                />
                {" "}{row.split} - {row.id}
              </td>
              <td>{row.name}</td>
            </tr>
            <ExpandableTableRow rows={row.children} />
          </Fragment>
          );
        });
      } else {
        return null;
      }
    };

    if (this.state.data) {
      return (
        <Fragment>
          {this.state.splitOption.join(', ')} <br />
          <button onClick={() => toggleSplit("name")}>
            camp name
          </button>
          <button onClick={() => toggleSplit("os")}>os</button>
          <button onClick={() => toggleSplit("country")}>country</button>
          <br />
          <ExpandableTableRow rows={this.state.data} />
        </Fragment>
      );
    } else {
      return null;
    }
  }
}

export default function App() {
  return (
    <div>
      <TableRowData />
    </div>
  );
}

在这里工作 example