vue：前端json数据 导出excel（Export2Excel）

一、背景：

导出的功能，通常后端处理好，前端直接通过地址进行下载即可，能不能是前端直接自己导出json文件，形成excel呢，当然可以。

二、实现步骤：

2.1、安装三个插件，分别是：file-saver、 xlsx、script-loader

npm install -S file-saver xlsx

npm install -D script-loader

2.2、utils目录下创建文件

2.3、Export2Excel.js

/* eslint-disable */
require('script-loader!file-saver');
// require('script-loader!src/vendor/Blob');
require('./Blob');
require('script-loader!xlsx/dist/xlsx.core.min');
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);
  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;
  /*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 };
      } else if (val.toString().charCodeAt(0) > 255) {
        /*再判断是否为中文*/
        return { wch: val.toString().length*2 + 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;
  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")
}

2.3、Blob.js

/* 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
));

2.4、业务代码测试：

    // 引入Export2Excel
    const {export_json_to_excel} = require('../../utils/Export2Excel');
    // json数据-导出Excel
    exportToExcel() {
      require.ensure([], () => {
        const tHeader = ['字段1', '字段2', '字段3', '字段4', '字段5'];
        const filterVal = ['name1', 'name2', 'name3', 'name4', 'name5'];
        this.listQuery.limit = 9999
        // 调用接口，获取数据
        getJsonList(this.listQuery).then(response => {
          if(response.code == 200){
            const exceldata = this.formatJson(filterVal, response.data.records);
            export_json_to_excel(tHeader, exceldata, '西药列表');  //对应下载文件的名字
          }
        });
        
      })
    },

经过测试下载成功，打开后内容显示正确，可放心使用。

三、欢迎交流指正，关注我，一起学习。

四、参考链接：

vue项目中最近使用的插件整理---（一）_沈尛的博客-CSDN博客

2分钟快速解决vue表格导出问题_李夏洛的博客-CSDN博客