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前端实现文件导出Excel

2022-05-05 15:03:55  阅读:121  来源: 互联网

标签:function URL Excel 前端 导出 let type data view


 工作中实现文件导出功能,记录一波。

downloadExcel() {
      this.$postJSON(`后端接口`,`接口传参`).then(res => {
        if (res.code !== 200 || !res) {
          this.$message({ message: '导出查询异常!', type: 'error' })
          return
        }
        const data = res.data
        if (!data || data.length === 0) {
          this.$message({ message: '没有可导出的数据!', type: 'warning' })
          return
        }
        require.ensure([], () => {
          const { export_json_to_excel } = require('../../utils/Export2Excel')
          const tHeader = ['表头名', '表头名'] 
          const filterVal = ['字段参数', '字段参数']
          const dataJson = this.formatJson(filterVal, data)
          export_json_to_excel(tHeader, dataJson, 'excel文件名', true)
        })
      })
    },
    formatJson(filterVal, jsonData) {
      return jsonData.map(v => filterVal.map(j => v[j]))
    }

 

Export2Excel.js
/* eslint-disable */

require('script-loader!file-saver');
require('./Blob');
require('script-loader!xlsx/dist/xlsx.core.min');
import XLSX from 'xlsx';
function generateArray(table) {
  let out = [];
  let rows = table.querySelectorAll('tr');
  let ranges = [];
  for (let R = 0; R < rows.length; ++R) {
    let outRow = [];
    let row = rows[R];
    let columns = row.querySelectorAll('td');
    for (let C = 0; C < columns.length; ++C) {
      let cell = columns[C];
      let colspan = cell.getAttribute('colspan');
      let rowspan = cell.getAttribute('rowspan');
      let 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 (let 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 (let k = 0; k < colspan - 1; ++k) outRow.push(null);
    }
    out.push(outRow);
  }
  return [out, ranges];
}

function datenum(v, date1904) {
  if (date1904) v += 1462;
  let 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) {
  let ws = {};
  let 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;
      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);
  console.log(ws)
  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(id) {
  let theTable = document.getElementById(id);
  console.log('a')
  let oo = generateArray(theTable);
  let ranges = oo[1];

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

  let 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;

  let 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 formatJson(filterVal, jsonData) {
  return jsonData.map(v => filterVal.map(j => v[j]));
}

export function export_json_to_excel(th, jsonData, defaultTitle) {

  /* original data */
  let data = jsonData;
  data.unshift(th);
  let ws_name = "SheetJS";
  let wb = new Workbook(),
  ws = sheet_from_array_of_arrays(data);
  let excelWidth = [];
  th.forEach(item =>{
    let ew = {};
    ew.wpx = item.length * 25;
    excelWidth.push(ew);
  })

  ws["!cols"]=excelWidth;

  /* add worksheet to workbook */
  wb.SheetNames.push(ws_name);
  wb.Sheets[ws_name] = ws;

  let wbOut = XLSX.write(wb, {
    bookType: 'xlsx',
    bookSST: false,
    type: 'buffer'
  });
  let title = defaultTitle || '列表';
  saveAs(new Blob([s2ab(wbOut)], {
    type: "application/octet-stream"
  }), title + ".xlsx")
}

 

Blob.js
/* Blob.js  * A Blob implementation  * 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));

 

标签:function,URL,Excel,前端,导出,let,type,data,view
来源: https://www.cnblogs.com/hspl/p/16224745.html

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