基础lucksheet实现前端导出excel文件

npm install exceljs
npm install file-saver

const Excel = require('exceljs')
const FileSaver = require('file-saver')

const EXCEL_TYPE ="application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=UTF-8";

var exportExcel = exports.exportExcel =  async function (luckysheet) { // 参数为luckysheet.getluckysheetfile()获取的对象
                                                                       // 1.创建工作簿，可以为工作簿添加属性
  const workbook = new Excel.Workbook()
  // 2.创建表格，第二个参数可以配置创建什么样的工作表
  luckysheet.every(function (table) {
    if (table.data.length === 0) return true
    const worksheet = workbook.addWorksheet(table.name)
    // 3.设置单元格合并,设置单元格边框,设置单元格样式,设置值
    setStyleAndValue(table.data, worksheet)
    setMerge(table.config.merge, worksheet)
    setBorder(table.config.borderInfo, worksheet)
    return true
  })
  // 4.写入 buffer
  const buffer = await workbook.xlsx.writeBuffer()
  const blob = new Blob([buffer], { type: EXCEL_TYPE });
  FileSaver.saveAs(blob, "download.xlsx");
}

var setMerge = function (luckyMerge = {}, worksheet) {
  const mergearr = Object.values(luckyMerge)
  mergearr.forEach(function (elem) { // elem格式：{r: 0, c: 0, rs: 1, cs: 2}
    // 按开始行，开始列，结束行，结束列合并（相当于 K10:M12）
    worksheet.mergeCells(elem.r + 1, elem.c + 1, elem.r + elem.rs, elem.c + elem.cs)
  })
}

var setBorder = function (luckyBorderInfo, worksheet) {
  if (!Array.isArray(luckyBorderInfo)) return
  luckyBorderInfo.forEach(function (elem) {
    let border = borderConvert(elem.borderType, elem.style, elem.color)
    let rang = elem.range[0]
    // console.log(rang.column_focus + 1, rang.row_focus + 1)
    worksheet.getCell(rang.row_focus + 1, rang.column_focus + 1).border = border
  })
}
var setStyleAndValue = function (cellArr, worksheet) {
  if (!Array.isArray(cellArr)) return
  cellArr.forEach(function (row, rowid) {
    row.every(function (cell, columnid) {
      if (!cell) return true
      let fill = fillConvert(cell.bg)
      let font = fontConvert(cell.ff, cell.fc, cell.bl, cell.it, cell.fs, cell.cl, cell.ul)
      let alignment = alignmentConvert(cell.vt, cell.ht, cell.tb, cell.tr)
      let value
      if (cell.f) {
        value = { formula: cell.f, result: cell.v }
      } else {
        value = cell.v
      }
      let target = worksheet.getCell(rowid + 1, columnid + 1)
      target.fill = fill
      target.font = font
      target.alignment = alignment
      target.value = value
      return true
    })
  })
}

var fillConvert = function (bg) {
  if (!bg) {
    return {}
  }
  let fill = {
    type: 'pattern',
    pattern: 'solid',
    fgColor: {argb: bg.replace('#', '')}
  }
  return fill
}

var fontConvert = function (ff = 0, fc = '#000000', bl = 0, it = 0, fs = 10, cl = 0, ul = 0) { // luckysheet：ff(样式), fc(颜色), bl(粗体), it(斜体), fs(大小), cl(删除线), ul(下划线)
  const luckyToExcel = {
    0: '微软雅黑',
    1: '宋体（Song）',
    2: '黑体（ST Heiti）',
    3: '楷体（ST Kaiti）',
    4: '仿宋（ST FangSong）',
    5: '新宋体（ST Song）',
    6: '华文新魏',
    7: '华文行楷',
    8: '华文隶书',
    9: 'Arial',
    10: 'Times New Roman ',
    11: 'Tahoma ',
    12: 'Verdana',
    num2bl: function (num) {
      return num === 0 ? false : true
    }
  }

  let font = {
    name: luckyToExcel[ff],
    family: 1,
    size: fs,
    color: {argb: fc.replace('#', '')},
    bold: luckyToExcel.num2bl(bl),
    italic: luckyToExcel.num2bl(it),
    underline: luckyToExcel.num2bl(ul),
    strike: luckyToExcel.num2bl(cl)
  }

  return font
}

var alignmentConvert = function (vt = 'default', ht = 'default', tb = 'default', tr = 'default') { // luckysheet:vt(垂直), ht(水平), tb(换行), tr(旋转)
  const luckyToExcel = {
    vertical: {
      0: 'middle',
      1: 'top',
      2: 'bottom',
      default: 'top'
    },
    horizontal: {
      0: 'center',
      1: 'left',
      2: 'right',
      default: 'left'
    },
    wrapText: {
      0: false,
      1: false,
      2: true,
      default: false
    },
    textRotation: {
      0: 0,
      1: 45,
      2: -45,
      3: 'vertical',
      4: 90,
      5: -90,
      default: 0
    }
  }

  let alignment = {
    vertical: luckyToExcel.vertical[vt],
    horizontal: luckyToExcel.horizontal[ht],
    wrapText: luckyToExcel.wrapText[tb],
    textRotation: luckyToExcel.textRotation[tr]
  }
  return alignment

}

var borderConvert = function (borderType, style = 1, color = '#000') { // 对应luckysheet的config中borderinfo的的参数
  if (!borderType) {
    return {}
  }
  const luckyToExcel = {
    type: {
      'border-all': 'all',
      'border-top': 'top',
      'border-right': 'right',
      'border-bottom': 'bottom',
      'border-left': 'left'
    },
    style: {
      0: 'none',
      1: 'thin',
      2: 'hair',
      3: 'dotted',
      4: 'dashDot', // 'Dashed',
      5: 'dashDot',
      6: 'dashDotDot',
      7: 'double',
      8: 'medium',
      9: 'mediumDashed',
      10: 'mediumDashDot',
      11: 'mediumDashDotDot',
      12: 'slantDashDot',
      13: 'thick'
    }
  }
  let template = {style: luckyToExcel.style[style], color: {argb: color.replace('#', '')}}
  let border = {}
  if (luckyToExcel.type[borderType] === 'all') {
    border['top'] = template
    border['right'] = template
    border['bottom'] = template
    border['left'] = template
  } else {
    border[luckyToExcel.type[borderType]] = template
  }
  return border
}