vue项目，前端导出excel

Posted 2022-06-26 fqh123

今天研究一下前端如何导出excel，边查边实践，边记录

1.安装依赖库

 

xlsx：这是一个功能强大的excel处理库，但是上手难度也很大，还涉及不少二进制的东西

 

file-saver:ES5新增了相关file,blob,fileList等API，但不是所有浏览器都支持，file-saver在没有原生支持saveAs的浏览器上实现了saveAs()接口

script-loader: 在全局上下文环境中执行一次js脚本。

 

npm install -D xlsx file-saver
npm install -s script-loader

 

二、引入相关依赖

上述部分依赖不支持import引入，所以需要使用‘script-loader‘将他们挂载到全局环境下；

其中的blob.js是github上的一个开源文件，对于浏览器不能原生支持blob的情况，提供了兼容解决方案,其地址是：https://github.com/eligrey/Blob.js

 script-loader使用方法：

require(‘script-loader!file-saver‘); //保存文件用
require(‘script-loader!vendor/Blob‘); //转二进制用
require(‘script-loader!xlsx/dist/xlsx.core.min‘); //xlsx核心

 

/* 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
    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
                ;
            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) 
                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 = this.data.length = 0;
            ;
            return FakeBlobBuilder;
        (view));

    view.Blob = function Blob(blobParts, options) 
        var type = options ? (options.type || "") : "";
        var builder = new BlobBuilder();
        if (blobParts) 
            for (var 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));

Blob,js

 三、封装Export2Excel.js，它对外暴露两个接口：export_table_to_excel和export_json_to_excel

 Export2Excel.js:

 

/* 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`);