Front-end implementation to export Excel

1. Prepare documents

1. Create excel folder

├─excel
   ├─Blob.js
   ├─Export2Excel.js

2. Blob.jsFolder contents↓

/* eslint-disable */
/* Blob.js*/

/*global self, unescape */
/*jslint bitwise: true, regexp: true, confusion: true, es5: true, vars: true, white: true,
  plusplus: true */

/*! @source http://purl.eligrey.com/github/Blob.js/blob/master/Blob.js */

(function (view) {
    
    
    "use strict";
  
    view.URL = view.URL || view.webkitURL;
  
    if (view.Blob && view.URL) {
    
    
      try {
    
    
        new Blob;
        return;
      } catch (e) {
    
    
      }
    }
  
    // Internally we use a BlobBuilder implementation to base Blob off of
    // in order to support older browsers that only have BlobBuilder
    var BlobBuilder = view.BlobBuilder || view.WebKitBlobBuilder || view.MozBlobBuilder || (function (view) {
    
    
      var
        get_class = function (object) {
    
    
          return Object.prototype.toString.call(object).match(/^\[object\s(.*)\]$/)[1];
        }
        , FakeBlobBuilder = function BlobBuilder() {
    
    
          this.data = [];
        }
        , FakeBlob = function Blob(data, type, encoding) {
    
    
          this.data = data;
          this.size = data.length;
          this.type = type;
          this.encoding = encoding;
        }
        , FBB_proto = FakeBlobBuilder.prototype
        , FB_proto = FakeBlob.prototype
        , FileReaderSync = view.FileReaderSync
        , FileException = function (type) {
    
    
          this.code = this[this.name = type];
        }
        , file_ex_codes = (
          "NOT_FOUND_ERR SECURITY_ERR ABORT_ERR NOT_READABLE_ERR ENCODING_ERR "
          + "NO_MODIFICATION_ALLOWED_ERR INVALID_STATE_ERR SYNTAX_ERR"
        ).split(" ")
        , file_ex_code = file_ex_codes.length
        , real_URL = view.URL || view.webkitURL || view
        , real_create_object_URL = real_URL.createObjectURL
        , real_revoke_object_URL = real_URL.revokeObjectURL
        , URL = real_URL
        , btoa = view.btoa
        , atob = view.atob
  
        , ArrayBuffer = view.ArrayBuffer
        , Uint8Array = view.Uint8Array
  
        , origin = /^[\w-]+:\/*\[?[\w\.:-]+\]?(?::[0-9]+)?/
      ;
      FakeBlob.fake = FB_proto.fake = true;
      while (file_ex_code--) {
    
    
        FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1;
      }
      // Polyfill URL
      if (!real_URL.createObjectURL) {
    
    
        URL = view.URL = function (uri) {
    
    
          var
            uri_info = document.createElementNS("http://www.w3.org/1999/xhtml", "a")
            , uri_origin
          ;
          uri_info.href = uri;
          if (!("origin" in uri_info)) {
    
    
            if (uri_info.protocol.toLowerCase() === "data:") {
    
    
              uri_info.origin = null;
            } else {
    
    
              uri_origin = uri.match(origin);
              uri_info.origin = uri_origin && uri_origin[1];
            }
          }
          return uri_info;
        };
      }
      URL.createObjectURL = function (blob) {
    
    
        var
          type = blob.type
          , data_URI_header
        ;
        if (type === null) {
    
    
          type = "application/octet-stream";
        }
        if (blob instanceof FakeBlob) {
    
    
          data_URI_header = "data:" + type;
          if (blob.encoding === "base64") {
    
    
            return data_URI_header + ";base64," + blob.data;
          } else if (blob.encoding === "URI") {
    
    
            return data_URI_header + "," + decodeURIComponent(blob.data);
          }
          if (btoa) {
    
    
            return data_URI_header + ";base64," + btoa(blob.data);
          } else {
    
    
            return data_URI_header + "," + encodeURIComponent(blob.data);
          }
        } else if (real_create_object_URL) {
    
    
          return real_create_object_URL.call(real_URL, blob);
        }
      };
      URL.revokeObjectURL = function (object_URL) {
    
    
        if (object_URL.substring(0, 5) !== "data:" && real_revoke_object_URL) {
    
    
          real_revoke_object_URL.call(real_URL, object_URL);
        }
      };
      FBB_proto.append = function (data/*, endings*/) {
    
    
        var bb = this.data;
        // decode data to a binary string
        if (Uint8Array && (data instanceof ArrayBuffer || data instanceof Uint8Array)) {
    
    
          var
            str = ""
            , buf = new Uint8Array(data)
            , i = 0
            , buf_len = buf.length
          ;
          for (; i < buf_len; i++) {
    
    
            str += String.fromCharCode(buf[i]);
          }
          bb.push(str);
        } else if (get_class(data) === "Blob" || get_class(data) === "File") {
    
    
          if (FileReaderSync) {
    
    
            var fr = new FileReaderSync;
            bb.push(fr.readAsBinaryString(data));
          } else {
    
    
            // async FileReader won't work as BlobBuilder is sync
            throw new FileException("NOT_READABLE_ERR");
          }
        } else if (data instanceof FakeBlob) {
    
    
          if (data.encoding === "base64" && atob) {
    
    
            bb.push(atob(data.data));
          } else if (data.encoding === "URI") {
    
    
            bb.push(decodeURIComponent(data.data));
          } else if (data.encoding === "raw") {
    
    
            bb.push(data.data);
          }
        } else {
    
    
          if (typeof data !== "string") {
    
    
            data += ""; // convert unsupported types to strings
          }
          // decode UTF-16 to binary string
          bb.push(unescape(encodeURIComponent(data)));
        }
      };
      FBB_proto.getBlob = function (type) {
    
    
        if (!arguments.length) {
    
    
          type = null;
        }
        return new FakeBlob(this.data.join(""), type, "raw");
      };
      FBB_proto.toString = function () {
    
    
        return "[object BlobBuilder]";
      };
      FB_proto.slice = function (start, end, type) {
    
    
        var args = arguments.length;
        if (args < 3) {
    
    
          type = null;
        }
        return new FakeBlob(
          this.data.slice(start, args > 1 ? end : this.data.length)
          , type
          , this.encoding
        );
      };
      FB_proto.toString = function () {
    
    
        return "[object Blob]";
      };
      FB_proto.close = function () {
    
    
        this.size = 0;
        delete this.data;
      };
      return FakeBlobBuilder;
    }(view));
  
    view.Blob = function (blobParts, options) {
    
    
      var type = options ? (options.type || "") : "";
      var builder = new BlobBuilder();
      if (blobParts) {
    
    
        for (var i = 0, len = blobParts.length; i < len; i++) {
    
    
          if (Uint8Array && blobParts[i] instanceof Uint8Array) {
    
    
            builder.append(blobParts[i].buffer);
          }
          else {
    
    
            builder.append(blobParts[i]);
          }
        }
      }
      var blob = builder.getBlob(type);
      if (!blob.slice && blob.webkitSlice) {
    
    
        blob.slice = blob.webkitSlice;
      }
      return blob;
    };
  
    var getPrototypeOf = Object.getPrototypeOf || function (object) {
    
    
      return object.__proto__;
    };
    view.Blob.prototype = getPrototypeOf(new view.Blob());
  }(
    typeof self !== "undefined" && self
    || typeof window !== "undefined" && window
    || this
  ));

Export2Excel.jsFolder contents↓

/* eslint-disable */
require('script-loader!file-saver');
// require('script-loader!src/vendor/Blob');
require('./Blob');
require('script-loader!xlsx/dist/xlsx.core.min');

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);
  console.log('a')
  var oo = generateArray(theTable);
  var ranges = oo[1];

  /* original data */
  var data = oo[0];
  var ws_name = "SheetJS";
  console.log(data);

  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")
}

function formatJson(jsonData) {
    
    
  console.log(jsonData)
}

// export function export_json_to_excel(th, jsonData, defaultTitle) {
    
    

//   /* original data */

//   var data = jsonData;
//   data.unshift(th);
//   var ws_name = "SheetJS";

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


//   /* 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'});
//   var title = defaultTitle || '列表'
//   saveAs(new Blob([s2ab(wbout)], {type: "application/octet-stream"}), title + ".xlsx")
// }


export function export_json_to_excel(th, jsonData, defaultTitle, autoWidth=true, bookType = 'xlsx', myRowFont = '1') {
    
    

  /* original data */

  var data = jsonData;
  data.unshift(th);
  var ws_name = "SheetJS";

  var wb = new Workbook(), ws = sheet_from_array_of_arrays(data);
  // console.log(autoWidth)
  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: 'xlsx', bookSST: false, type: 'binary'});
  var title = defaultTitle || '列表'
  saveAs(new Blob([s2ab(wbout)], {
    
    type: "application/octet-stream"}), title + ".xlsx")
}

2. Export Excel file

  // 导出写好的文件
  const {
    
    
    export_json_to_excel
  } = require('/excel/Export2Excel');
  // 定义Excel文件的表头
  const tHeader = ['工號','姓名','課程系列','課程名稱','課程類別'];
  // 表头对应的字段
  const filterVal = ['empID','empName','courseSeriesName','courseName','courseType'];
  const data = list.map(v => filterVal.map(j => v[j]))
  export_json_to_excel(tHeader,data,'文件名');