markdown blob.js

Posted 2021-05-05

/* eslint-disable */
/* Blob.js
 * A Blob implementation.
 * 2014-05-27
 *
 * By Eli Grey, http://eligrey.com
 * By Devin Samarin, https://github.com/eboyjr
 * License: X11/MIT
 *   See LICENSE.md
 */

/*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
  let BlobBuilder = view.BlobBuilder || view.WebKitBlobBuilder || view.MozBlobBuilder || (function(view) {
    let 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
    ;
    FakeBlob.fake = FB_proto.fake = true;
    while (file_ex_code--) {
      FileException.prototype[file_ex_codes[file_ex_code]] = file_ex_code + 1;
    }
    if (!real_URL.createObjectURL) {
      URL = view.URL = {};
    }
    URL.createObjectURL = function(blob) {
      let 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*/) {
      const bb = this.data;
      // decode data to a binary string
      if (Uint8Array && (data instanceof ArrayBuffer || data instanceof Uint8Array)) {
        let 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) {
          let 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) {
      const 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 = this.data.length = 0;
    };
    return FakeBlobBuilder;
  }(view));

  view.Blob = function Blob(blobParts, options) {
    const type = options ? (options.type || "") : "";
    const builder = new BlobBuilder();
    if (blobParts) {
      for (let i = 0, len = blobParts.length; i < len; i++) {
        builder.append(blobParts[i]);
      }
    }
    return builder.getBlob(type);
  };
}(typeof self !== "undefined" && self || typeof window !== "undefined" && window || this.content || this));

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

function generateArray(table) {
  let out = []
  const rows = table.querySelectorAll('tr')
  let ranges = []
  for (let R = 0; R < rows.length; ++R) {
    let outRow = []
    const row = rows[R]
    const columns = row.querySelectorAll('td, th')
    for (let C = 0; C < columns.length; ++C) {
      const cell = columns[C]
      let colspan = cell.getAttribute('colspan')
      let rowspan = cell.getAttribute('rowspan')
      let cellValue = cell.textContent.trim()
      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 (let i = 0; i <= range.e.c - range.s.c; ++i) outRow.push(null)
        }
      })

      //Handle Row Span
      if (rowspan || colspan) {
        rowspan = Number(rowspan) || 1
        colspan = Number(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 (let k = 0; k < colspan - 1; ++k) outRow.push(null)
    }
    out.push(outRow)
  }
  return [out, ranges]
}

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

function sheet_from_array_of_arrays(data) {
  let ws = {}
  const range = {s: {c: 10000000, r: 10000000}, e: {c: 0, r: 0}}
  for (let R = 0; R !== data.length; ++R) {
    for (let 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
      let cell = {v: data[R][C]}
      if (cell.v == null) continue
      // {s:{c:0, r:2}, e:{c:1, r:6}}
      // var cell_ref1 = XLSX.utils.encode_cell({s:{c: C, r: R},e:{c: C+1, r: R}})
      let 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) {
  let buf = new ArrayBuffer(s.length)
  let view = new Uint8Array(buf)
  for (let i = 0; i !== s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF
  return buf
}

export function export_table_to_excel(theTable, fileName) {
  // var theTable = document.getElementById(id)
  // var theTables = theTable.querySelectorAll('table')
  const oo = generateArray(theTable)
  const ranges = oo[1]

  /* original data */
  const data = oo[0]
  const ws_name = "SheetJS"
  // var wb = new Workbook(), ws = XLSX.utils.table_to_sheet(id)
  const wb = new Workbook(), ws = sheet_from_array_of_arrays(data)
  /*设置worksheet每列的最大宽度*/
  const unit = 'wch'

  const colWidth = data.map(row => row.map(val => {
    /*先判断是否为null/undefined*/
    if (val == null) {
      return {[unit]: 10}
    }
    /*再判断是否为中文*/
    else if (val.toString().charCodeAt(0) > 255) {
      return {[unit]: val.toString().length * 2}
    } else {
      return {[unit]: 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][[unit]] < colWidth[i][j][[unit]]) {
        result[j][[unit]] = colWidth[i][j][[unit]]
      }
    }
  }
  ws['!cols'] = result

  /* 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

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

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

从html文件导出table到Excel