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【导出Excel】 JS的Excel导出库 Export2Excel

开发技术 开发技术 2022-07-26 次浏览

Export2Excel库默认放在ElementUI-Admin项目的src/vendor包中

不是通过package.json安装的依赖

 

 

这里直接贴库的源码:

/* eslint-disable */
require('script-loader!file-saver');
import XLSX from 'xlsx'

function generateArray(table) {
  var out = [];
  var rows = table.querySelectorAll('tr');
  var ranges = [];
  for (var R = 0; R < rows.length; ++R) {
    var outRow = [];
    var row = rows[R];
    var columns = row.querySelectorAll('td');
    for (var C = 0; C < columns.length; ++C) {
      var cell = columns[C];
      var colspan = cell.getAttribute('colspan');
      var rowspan = cell.getAttribute('rowspan');
      var cellValue = cell.innerText;
      if (cellValue !== "" && cellValue == +cellValue) cellValue = +cellValue;

      //Skip ranges
      ranges.forEach(function (range) {
        if (R >= range.s.r && R <= range.e.r && outRow.length >= range.s.c && outRow.length <= range.e.c) {
          for (var i = 0; i <= range.e.c - range.s.c; ++i) outRow.push(null);
        }
      });

      //Handle Row Span
      if (rowspan || colspan) {
        rowspan = rowspan || 1;
        colspan = colspan || 1;
        ranges.push({
          s: {
            r: R,
            c: outRow.length
          },
          e: {
            r: R + rowspan - 1,
            c: outRow.length + colspan - 1
          }
        });
      };

      //Handle Value
      outRow.push(cellValue !== "" ? cellValue : null);

      //Handle Colspan
      if (colspan)
        for (var k = 0; k < colspan - 1; ++k) outRow.push(null);
    }
    out.push(outRow);
  }
  return [out, ranges];
};

function datenum(v, date1904) {
  if (date1904) v += 1462;
  var epoch = Date.parse(v);
  return (epoch - new Date(Date.UTC(1899, 11, 30))) / (24 * 60 * 60 * 1000);
}

function sheet_from_array_of_arrays(data, opts) {
  var ws = {};
  var range = {
    s: {
      c: 10000000,
      r: 10000000
    },
    e: {
      c: 0,
      r: 0
    }
  };
  for (var R = 0; R != data.length; ++R) {
    for (var C = 0; C != data[R].length; ++C) {
      if (range.s.r > R) range.s.r = R;
      if (range.s.c > C) range.s.c = C;
      if (range.e.r < R) range.e.r = R;
      if (range.e.c < C) range.e.c = C;
      var cell = {
        v: data[R][C]
      };
      if (cell.v == null) continue;
      var cell_ref = XLSX.utils.encode_cell({
        c: C,
        r: R
      });

      if (typeof cell.v === 'number') cell.t = 'n';
      else if (typeof cell.v === 'boolean') cell.t = 'b';
      else if (cell.v instanceof Date) {
        cell.t = 'n';
        cell.z = XLSX.SSF._table[14];
        cell.v = datenum(cell.v);
      } else cell.t = 's';

      ws[cell_ref] = cell;
    }
  }
  if (range.s.c < 10000000) ws['!ref'] = XLSX.utils.encode_range(range);
  return ws;
}

function Workbook() {
  if (!(this instanceof Workbook)) return new Workbook();
  this.SheetNames = [];
  this.Sheets = {};
}

function s2ab(s) {
  var buf = new ArrayBuffer(s.length);
  var view = new Uint8Array(buf);
  for (var i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF;
  return buf;
}

export function export_table_to_excel(id) {
  var theTable = document.getElementById(id);
  var oo = generateArray(theTable);
  var ranges = oo[1];

  /* original data */
  var data = oo[0];
  var ws_name = "SheetJS";

  var wb = new Workbook(),
    ws = sheet_from_array_of_arrays(data);

  /* add ranges to worksheet */
  // ws['!cols'] = ['apple', 'banan'];
  ws['!merges'] = ranges;

  /* add worksheet to workbook */
  wb.SheetNames.push(ws_name);
  wb.Sheets[ws_name] = ws;

  var wbout = XLSX.write(wb, {
    bookType: 'xlsx',
    bookSST: false,
    type: 'binary'
  });

  saveAs(new Blob([s2ab(wbout)], {
    type: "application/octet-stream"
  }), "test.xlsx")
}

export function export_json_to_excel({
  multiHeader = [],
  header,
  data,
  filename,
  merges = [],
  autoWidth = true,
  bookType=  'xlsx'
} = {}) {
  /* original data */
  filename = filename || 'excel-list'
  data = [...data]
  data.unshift(header);

  for (let i = multiHeader.length-1; i > -1; i--) {
    data.unshift(multiHeader[i])
  }

  var ws_name = "SheetJS";
  var wb = new Workbook(),
    ws = sheet_from_array_of_arrays(data);

  if (merges.length > 0) {
    if (!ws['!merges']) ws['!merges'] = [];
    merges.forEach(item => {
      ws['!merges'].push(XLSX.utils.decode_range(item))
    })
  }

  if (autoWidth) {
    /*设置worksheet每列的最大宽度*/
    const colWidth = data.map(row => row.map(val => {
      /*先判断是否为null/undefined*/
      if (val == null) {
        return {
          'wch': 10
        };
      }
      /*再判断是否为中文*/
      else if (val.toString().charCodeAt(0) > 255) {
        return {
          'wch': val.toString().length * 2
        };
      } else {
        return {
          'wch': val.toString().length
        };
      }
    }))
    /*以第一行为初始值*/
    let result = colWidth[0];
    for (let i = 1; i < colWidth.length; i++) {
      for (let j = 0; j < colWidth[i].length; j++) {
        if (result[j]['wch'] < colWidth[i][j]['wch']) {
          result[j]['wch'] = colWidth[i][j]['wch'];
        }
      }
    }
    ws['!cols'] = result;
  }

  /* add worksheet to workbook */
  wb.SheetNames.push(ws_name);
  wb.Sheets[ws_name] = ws;

  var wbout = XLSX.write(wb, {
    bookType: bookType,
    bookSST: false,
    type: 'binary'
  });
  saveAs(new Blob([s2ab(wbout)], {
    type: "application/octet-stream"
  }), `${filename}.${bookType}`);
}

  

主要使用的API是这两个方法:

// 1、提供一个table表格的dom的id属性的元素值,生成excel数据并导出
export_table_to_excel()

// 2、提供JS数据来生成Excel文件
export_json_to_excel()

  

1、在使用的组件中引入导出库

import { export_json_to_excel } from '@/vendor/Export2Excel'

 

2、通用的做法是后台提供一个导出数据的接口

返回一个List数据,元素是对象,这里不赘述后台接口的开发

import { getVitalLimitConfigExportData } from '@/api/smrz/setting'

JSON数据格式:

{
  "code": 200,
  "data": [
    {
      "areaName": "连江县",
      "cityName": "福州市",
      "createDate": "2022-07-26 09:20:46",
      "id": 6,
      "liveScore": 233,
      "placeArea": "350122",
      "placeCity": "350100",
      "placeCode": "3501228412",
      "placeName": "天运网吧",
      "updateDate": "2022-07-26 09:22:06",
      "videoScore": 444
    },
    {
      "areaName": "吉州区",
      "cityName": "吉安市",
      "createDate": "2021-08-11 10:26:39",
      "id": 5,
      "liveScore": 0.06,
      "placeArea": "362401",
      "placeCity": "362400",
      "placeCode": "3624018888",
      "placeName": "电竞酒店扣点账号",
      "updateDate": "2021-08-11 14:47:38",
      "videoScore": 0.06
    },
    {
      "areaName": "玉山县",
      "cityName": "上饶市",
      "createDate": "2021-08-11 10:25:00",
      "id": 4,
      "liveScore": 0.06,
      "placeArea": "362323",
      "placeCity": "362300",
      "placeCode": "3623230555",
      "placeName": "万象测试",
      "updateDate": "2021-08-11 10:25:00",
      "videoScore": 0.06
    },
    {
      "areaName": "玉山县",
      "cityName": "上饶市",
      "createDate": "2021-08-11 10:21:24",
      "id": 2,
      "liveScore": 0.06,
      "placeArea": "362323",
      "placeCity": "362300",
      "placeCode": "3623230236",
      "placeName": "网盾236",
      "updateDate": "2021-08-11 10:21:24",
      "videoScore": 0.06
    },
    {
      "areaName": "信州区",
      "cityName": "上饶市",
      "createDate": "2021-08-11 09:50:26",
      "id": 1,
      "liveScore": 0.06,
      "placeArea": "362301",
      "placeCity": "362300",
      "placeCode": "3623230235",
      "placeName": "网盾235",
      "updateDate": "2021-09-03 09:17:22",
      "videoScore": 0.06
    }
  ],
  "message": "操作成功!",
  "status": "success"
}

  

3、编写导出方法:

页面编写触发组件,声明绑定的执行方法

<el-button
  icon="el-icon-upload2"
  @click="exportExcel"
>导出Excel</el-button>

  

方法实现:

export_json_to_excel的参数有3个必要参数

- sheet页标题头 

- sheet页标题头的key

- 格式化后的js数据

 

标题头 + 标题头的key

      excelHeader: [
        '场所名称',
        '场所编号',
        '所属区域',
        '图片活体阀值',
        '视频活体阀值',
        '创建时间',
        '更新时间'
      ],
      excelHeaderKey: [
        'placeName',
        'placeCode',
        'areaName',
        'liveScore',
        'videoScore',
        'createDate',
        'updateDate'
      ]

  

formatJson的作用是把【接口数据】按照【标题头的key】赋值

在这里可以翻译字段,处理特殊字段,或者自定义匹配

v是当前遍历的接口List的对象,j是标题头key的值,也就是字段名

    formatJson(filterVal, jsonData) {
      return jsonData.map(v => filterVal.map(j => {
        // console.log(v, j)
        if (j === 'areaName') return v['cityName'] + v['areaName']
        else return v[j]
      }))
    }

这里列举以前在外包写的比较复杂的处理:

【导出Excel】 JS的Excel导出库 Export2Excel

 

下面是最后的实现写法

    async exportExcel() {
      const { data: res } = await getVitalLimitConfigExportData(this.param)
      const fileName = spawnExcelFileName('百度云活体阈值配置表')

      const data = this.formatJson(this.excelHeaderKey, res)
      export_json_to_excel({
        header: this.excelHeader,
        data: data,
        filename: fileName
      })
    },

  

最后导出结果:

【导出Excel】 JS的Excel导出库 Export2Excel

 

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