前言
今天再开发中遇到一件事情，就是怎样用查询到的表格导出excel文件？网上有许多方法，最多的就是用数据流的方式。后端给出的方案也是提供一个借口，访问后的到一个文件，然后前端建立虚拟dom进行下载。 我看到网上有说这一块工作也可以前端去实现便使我灵光一闪。
导入依赖
// npm
npm install -S file-saver xlsx
npm install -D script-loader
复制代码导入Bolb.js与Export2Excel.js
首先拷贝以下两个文件代码： Export2Excel.js
/* eslint-disable */
require('script-loader!file-saver');
require('script-loader!vendor/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")
}
复制代码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));
复制代码因为我们在Export2Excel.js中设置的Blob路径为vendor，所以我们要在src下建立相关文件夹并放入这两个js。
设置导出表格数据
假设我们需要导出一个这样的表格
数据
// data
dataList: [
{ name: "张明", loginTime: 16, id: 1, department: "生产部", sex: "男" },
{ name: "小金", loginTime: 11, id: 2, department: "生产部", sex: "女" },
{ name: "小凌", loginTime: 21, id: 3, department: "生产部", sex: "男" },
{ name: "盖伦", loginTime: 5, id: 4, department: "测试部", sex: "男" }
]
复制代码html
<table border>
<tr>
<th>ID</th>
<th>名称</th>
<th>登陆次数</th>
<th>部门</th>
</tr>
<tr v-for="item in dataList" :key="item.id">
<td>{{ item.id }}</td>
<td>{{ item.name }}</td>
<td>{{ item.loginTime }}</td>
<td>{{ item.department }}</td>
</tr>
</table>
<button @click="exportExcel">导出信息</button>
复制代码methods
// 导出excel
exportExcel() {
// 引入文件
const { export_json_to_excel } = require("vendor/Export2Excel.js");
// 表头
const tHeader = ["ID", "名称", "登陆次数", "部门"];
// table表格中对应的属性名
const filterVal = ["id", "name", "loginTime", "department"];
// 表格绑定数据转json
const data = this.formatJson(filterVal, this.dataList);
export_json_to_excel(
tHeader,
data,
"部门登陆信息" + new Date().toLocaleDateString()
); // 对应下载文件的名字
},
// 导出列表格式化数据的方法
formatJson(filterVal, jsonData) {
return jsonData.map(v => filterVal.map(j => v[j]));
}
复制代码展示效果
到此，前端导出功能实现。这种方式的优势在于:1.不用请求后端获取文件。2.所见即所得，前端可有灵活地把控输出的数据，不用因为导出的数据有差错而拉着后端一起联调。
多sheet导出
我们可能有时候会遇到对Excel多sheet的操作，比如部门的多季度绩效分多sheet导出。
我们需要在Export2Excel.js中添加一个方法:
/**
* 多sheet导出
* @param {Array} th 表头
* @param {Array} jsonDatas 数据集
* @param {String} defaultTitle 导出的excel名称
* @param {Array} sheetNames sheet名称集
*/
export function export_season_to_excel(th, jsonDatas, defaultTitle, sheetNames) {
var wb = new Workbook()
jsonDatas.forEach((item, index) => {
var data = item;
data.unshift(th);
var ws_name = sheetNames[index];
var 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")
}
复制代码页面中的data内容：
// data 季度绩效数据
seasonDatas: [
[
{ name: "张明", score: 72 },
{ name: "小金", score: 21 },
{ name: "小凌", score: 16 },
{ name: "盖伦", score: 84 }
],
[
{ name: "张明", score: 32 },
{ name: "小金", score: 54 },
{ name: "小凌", score: 45 },
{ name: "盖伦", score: 26 }
],
[
{ name: "张明", score: 67 },
{ name: "小金", score: 87 },
{ name: "小凌", score: 45 },
{ name: "盖伦", score: 78 }
],
[
{ name: "张明", score: 54 },
{ name: "小金", score: 34 },
{ name: "小凌", score: 26 },
{ name: "盖伦", score: 34 }
]
]
复制代码html
<div class="season">
<template v-for="(item, index) in seasonDatas">
<div :key="index">
{{ `第${index + 1}季度绩效` }}
<table border>
<tr>
<th>名称</th>
<th>绩效分</th>
</tr>
<tr v-for="(scoreItem, scoreindex) in item" :key="scoreindex">
<td>{{ scoreItem.name }}</td>
<td>{{ scoreItem.score }}</td>
</tr>
</table>
</div>
</template>
</div>
<button @click="exportSeason">导出绩效信息</button>
复制代码执行方法
// methods 导出绩效信息excel
exportSeason() {
// 引入文件
const { export_season_to_excel } = require("vendor/Export2Excel.js");
// 表头
const tHeader = ["名称", "绩效分"];
// table表格中对应的属性名
const filterVal = ["name", "score"];
let datas = [];
let sheets = [];
this.seasonDatas.forEach((item, index) => {
// 表格绑定数据转json
datas.push(this.formatJson(filterVal, item));
sheets.push(`第${index + 1}季度绩效`);
});
export_season_to_excel(
tHeader,
datas,
"部门季度绩效" + new Date().toLocaleDateString(),
sheets
); // 对应下载文件的名字
},
复制代码展示效果：
至此，多Sheet导出我们也完成了。
项目地址
存疑解析
大数据导出和自定义表头名称
在文章发出后大家对大数据导出和怎么自定义表头存在疑惑，我这边设置了一个可以自定义导出规模的例子。
html部分
<p><input type="number" v-model="rows" />行</p>
<p><input type="number" v-model="cols" />列</p>
<button @click="outPutBigData">导出自定义大小表格信息</button>
复制代码js部分
// data
rows: 100, // 行
cols: 100 // 列
// methods
// 导出自定义数据
outPutBigData() {
// 引入文件
const { export_json_to_excel } = require("vendor/Export2Excel.js");
// 表头
let tHeader = [];
// table表格中对应的属性名
let filterVal = [];
// 需要导出的内容
let pushData = [];
// 自定义生成列
for (let i = 0; i < this.cols * 1; i++) {
tHeader.push(`第${i + 1}列数据`);
filterVal.push(i);
}
// 生成自定义数据
for (let j = 0; j < this.rows * 1; j++) {
let pushObj = {};
for (let i = 0; i < this.cols * 1; i++) {
// 这边为展示数据不一致性设置为随机数
pushObj[i] = Math.random();
}
// 插入一条数据
pushData.push(pushObj);
}
// ---至此模拟后端请求数据结束---
// 表格绑定数据转json
const data = this.formatJson(filterVal, pushData);
export_json_to_excel(
tHeader,
data,
"自定义导出数据" + new Date().toLocaleDateString()
); // 对应下载文件的名字
},
复制代码演示效果:
为方便大家直观的看到，我们这次导出10000行10列的随机数据.可以看到，其中的列名称我也是自动生成的。