<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>封装属于自己的AJAX类库</title>
</head>
<body>
<script>
//自执行函数
~function(){
class ajaxClass{
//=>AJAX四步操作：send ajax
init(){
//这里的this就是实例example
let xhr = new XMLHttpRequest();
xhr.onreadystatechange = ()=>{
if(xhr.readyState===4&&/^(2|3)\d{2}$/.test(xhr.status)){
let result = xhr.responseText;
//dataType的处理
try {
switch (this.dataType.toUpperCase()){
case 'TEXT':
case 'HTML':
break;
case 'JSON':
result = JSON.parse(result);
break;
case 'XML':
result = xhr.responseXML;
}
}catch (e){
console.log(e.message);
}
this.success(result);
}
}
//=>data的处理
if(this.data !==null){
this.formatData();
if(this.isGET){
//如果是get请求
this.url += this.querySymbol()+this.data;
this.data = null;
}
}
//=>cache的处理
this.isGET?this.cacheFn():null;
xhr.open(this.method,this.url,this.async);
xhr.send(this.data);
}
//把传递的对象格式data转换为字符串格式类型
formatData(){
//this指向当前实例example
//检测this.data是否是一个对象
if({}.toString.call(this.data)==='[object Object]'){
let obj = this.data,
str = ``;
for(let key in obj){
str += `${key}=${obj[key]}&`;
}
str = str.replace(/&$/,'');//把末尾的&进行替换
this.data = str;
}
}
cacheFn(){
//this指向当前实例example
!this.cache ?this.url +=`${this.querySymbol}_=${Math.random()}`:null;
}
//符号查询
querySymbol(){
//this孩纸指向当前实例example
return this.url.indexOf('?')>-1?'&':'?';
}
}
//=>参数初始化 init parameters
window.ajax = function ({
url=null,
method='GET',
type=null,
data=null,
dataType='JSON',
cache=true,
async=true,
success=null
}={}) {
let example = new ajaxClass();//example就是ajaxClass的实例
/*['url','method','data','dataType','cache','async','success'].forEach((item)=>{
if(item==='method'){
_this.method = type===null?method:type;
return;
}if(item === 'success'){
_this.success = typeof success === 'function'?success:new Function();
return;
}
_this[item] = eval(item);
})*/
example.url = url;
example.method = type===null?method:type;
example.data = data;
example.dataType = dataType;
example.async = async;
example.success = typeof success === 'function'?success:new Function();
example.isGET = /^(GET|DELETE|HEAD)$/i.test(example.method);
example.init();//执行init方法
return example;
};
}();
ajax({
url:'product.json',
method:'post',
cache:false,
data:{
name:'zhangsan',
age:18
},
dataType:'text',
success: result=>{
console.log(result);
}
})
</script>
</body>
</html>
