利用HTML/HTML5中的download属性来实现数据csv

纯前端实现文件的下载，将数据导出为csv文件。

download 属性规定被下载的超链接目标。

1. 基础写法

<a href="url" download="filename">下载文件</a>

2.浏览器兼容

http://7xtfps.com1.z0.glb.clouddn.com/1.png

检测测当前浏览器是否支持download属性
var isSupportDownload = 'download' in document.createElement('a');

3. CSV： 逗号分隔值文件格式

文件以纯文本形式存储表格数据（数字和文本）。纯文本意味着该文件是一个字符序列，不含必须像二进制数字那样被解读的数据。CSV文件由任意数目的记录组成，记录间以某种换行符分隔；每条记录由字段组成，字段间的分隔符是其它字符或字符串，最常见的是逗号或制表符。通常，所有记录都有完全相同的字段序列。
其文件内容为以下内容

"#","姓名","照片","手机","性别","生日","会员卡种类","会员卡号"
"1","arron","xxx","13890909090","male","930106","good","11809"
"2","steven","xxx","13890908890","male","930206","good","11209"
"3","jack","xxx","13890220090","male","930906","bad","11809"

实现原理：拼接字符串，生成csvstring，再利用a标签download的新属性实现csv文件的生成

4. 实践

data:
var people = [
    {
        "name": "Arron",
        "age: : "22",
        "sex" : "男",
        "birthday": "1993-01-06",
        "phone": "13187890289",
        "hobby": "basketball"
    },
    {
        "name": "Jack",
        "age: : "24",
        "sex" : "男",
        "birthday": "1991-02-22",
        "phone": "13567454389",
        "hobby": "football"
    },
    {
        "name": "Alice",
        "age: : "21",
        "sex" : "女",
        "birthday": "1996-11-26",
        "phone": "13187889509",
        "hobby": "reading"
    }
]

code: 

s1. 我们用一个数组来存一行数据,所以第一行用一个数组来保存字段名
var head = [['name','age','sex','birthday','phone','hobby']];

s2. 将数据push到大数组中
var p = people;
for(var i = 0 ; i < p.length; i++) {
    head.push([p[i].name, p[i].age, p[i].sex, p[i].birthday, p[i].phone, p[i].hobby]);
}

s3. 按照csv文件内容格式，把每个数组用 , 连接，形成一行，并存入新数组
var csvRows = [];
for(var i = 0 ; i < head.length; i++) {
    csvRows.push(head[i].join(','))
}

s4. 把新数组用 \n 回车连接，形成csvString

var csvString = csvRows.join('\n');

//BOM的方式解决EXCEL乱码问题
var BOM = '\uFEFF';
csvString = BOM + csvString;

s5. 创建a标签
var a = document.createElement('a');
a.href = 'data:attachment/csv,' +  encodeURI(csvString);
a.target = '_blank';
a.download = 'info.csv';
document.body.appendChild(a); // Firefox 中必须这么写，不然不会起效果
a.click();
document.body.removeChild(a);

在线Demo

顺便说一下：关于文件的操作还是交给后端处理吧-，-