1、需求引入
最近遇到的一个问题，特意写个笔记记录一下，iview的表格数据导出excel文件，然后去官网翻阅API，发现导出的csv后缀的文件,然后官网上明确的说明了只支持导出CSV类型的文件，但是公司需求给出的是需要XLSX，后来通过查阅资料找到了两种解决这类问题的方案：1.修改源码，添加一个导出XLSX文件后缀的方法，然后把这个方法类似于CSV的方法一样暴露出去 2. 利用Blob.js去解决
我今天使用的是通过Blob.js去处理的，下面写下详细的解决过程：
1.1、CSV后缀结尾的文件和XLSX后缀结尾的文件二者的区别
csv是文本文件,用记事本就能打开，XLS是二进制的文件只有用EXCEL才能打开。
1、xls文件就是Microsoft excel电子表格的文件格式。
2、csv是最通用的一种文件格式，它可以非常容易地被导入各种PC表格及数据库中。 此文件，一行即为数据表的一行。生成数据表字段用半角逗号隔开。
2、npm 安装
使用这种解决方法需要一定的插件库，因此，要先打开终端安装插件
npm install file-saver@1.3.3 用来保存文件的
npm install --save-dev script-loader 由于由于这几个文件不支持import引入，所以我们需要script-loader来将他们挂载到全局开发环境下面去。
npm install xlsx 指的是 js-xlsx
npm install jszip 压缩文件
3、在src目录下创建一个公共的js文件夹
我是在src目录下新建了一个叫vendor的文件夹，这里面将要放几个封装好的插件（详细了解的话可以查阅官网文档）
首先，先创建第一个js文件Blob.js
3.1、Blob.js
blob的存在，允许我们可以通过js直接操作二进制数据。
//Blog.js官网的，用来转二进制的。
(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));
3.2、Export2Excel.js
主要是处理好数据并且暴露了两个接口export_table_to_excel和export_json_to_excel,我们常用export_json_to_excel因为更加的可控一点，我们可以自由的处理数据。
/* eslint-disable */
require('script-loader!file-saver');
require('script-loader!@/vendor/Blob');
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({ header, data, filename = 'excel-list', autoWidth = true } = {}) {
/* original data */
data = [...data]
data.unshift(header);
var ws_name = "SheetJS";
var wb = new Workbook(),
ws = sheet_from_array_of_arrays(data);
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: 'xlsx', bookSST: false, type: 'binary' });
saveAs(new Blob([s2ab(wbout)], { type: "application/octet-stream" }), filename + ".xlsx");
}
3.3、Export2Zip.js
暴漏出export_txt_to_zip这个接口，用来导出压缩文件的
/* eslint-disable */
require('script-loader!file-saver');
import JSZip from 'jszip'
export function export_txt_to_zip(th, jsonData, txtName, zipName) {
const zip = new JSZip()
const txt_name = txtName || 'file'
const zip_name = zipName || 'file'
const data = jsonData
let txtData = `${th}\r\n`
data.forEach((row) => {
let tempStr = ''
tempStr = row.toString()
txtData += `${tempStr}\r\n`
})
zip.file(`${txt_name}.txt`, txtData)
zip.generateAsync({type:"blob"}).then((blob) => {
saveAs(blob, `${zip_name}.zip`)
}, (err) => {
alert('导出失败')
})
}
4、开始导出
4.1、首先我们要创建一个导出的按钮
我这里使用的是iview组件的
<Button type="primary" @click="exportData()">
<Icon type="ios-download-outline"></Icon>
导出excel
</Button>
4.2、调取后台接口拿到后台的数据
我这里的后台数据datalist这个数组数据，这个根据自身需求情况来
getData(pn) {
getLoglist(pn, this.ps, this.time_begin, this.time_end).then((res) => {
this.datalist = res.data.records;
this.totla = res.data.total;
});
}
4.3、在data选项中定义变量
listLoading: true,
downloadLoading: false,
filename: "系统日志", //这个是我的文件导出的名称
datalist: [],
4.4、在方法中开始处理导出
//导出.xlsx文件
exportData() {
import("@/vendor/Export2Excel").then((excel) => {
//表格的表头列表
const tHeader = [
"creator",
"roleName",
"createTime",
"ipAddr",
"description",
];
//相对应的数据中的字段
const filterVal = [
"creator",
"roleName",
"createTime",
"ipAddr",
"description",
];
const list = this.datalist;
const data = this.formatJson(filterVal, list);
excel.export_json_to_excel({
header: tHeader,
data,
filename: this.filename,
});
this.downloadLoading = false;
});
},
formatJson(filterVal, jsonData) {
return jsonData.map((v) =>
filterVal.map((j) => {
return v[j];
})
);
},
4.5、注意事项
切记要在formatJson传参的时候将后台数据(需要处理的数据)传入，否则是无法导出的，或者会出现报错。
5、效果展示
image.png
