Native js achieve http request

Sometimes a page request is used, but do not want the introduction jquery, ajax case where it is not used, may be used directly encapsulate native js function. Native js conducted by the XMLHttpRequest object. Specific can be found W3school XMLHttpRequest object.

1, the function call request packaging:

function httpRequest(paramObj,fun,errFun) {
	var xmlhttp = null;
	/*创建XMLHttpRequest对象，
	 *老版本的 Internet Explorer（IE5 和 IE6）使用 ActiveX 对象：new ActiveXObject("Microsoft.XMLHTTP")
	 * */
	if(window.XMLHttpRequest) {
		xmlhttp = new XMLHttpRequest();
	}else if(window.ActiveXObject) {
		xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
	}
	/*判断是否支持请求*/
	if(xmlhttp == null) {
		alert('你的浏览器不支持XMLHttp');
		return;
	}
	/*请求方式，并且转换为大写*/
	var httpType = (paramObj.type || 'GET').toUpperCase();
	/*数据类型*/
	var dataType = paramObj.dataType || 'json';
	/*请求接口*/
	var httpUrl = paramObj.httpUrl || '';
	/*是否异步请求*/
	var async = paramObj.async || true;
	/*请求参数--post请求参数格式为：foo=bar&lorem=ipsum*/
	var paramData = paramObj.data || [];
	var requestData = '';
	for(var name in paramData) {
		requestData += name + '='+ paramData[name] + '&';
	}
	requestData = requestData == '' ? '' : requestData.substring(0,requestData.length - 1);
	console.log(requestData)
	
	/*请求接收*/
	xmlhttp.onreadystatechange = function() {
    if(xmlhttp.readyState == 4 && xmlhttp.status == 200) {
      /*成功回调函数*/
      fun(xmlhttp.responseText);
    }else{
    	/*失败回调函数*/
    	errFun;
    }
	}			
	
	/*接口连接，先判断连接类型是post还是get*/
	if(httpType == 'GET') {
		xmlhttp.open("GET",httpUrl,async);
	xmlhttp.send(null);
	}else if(httpType == 'POST'){
		xmlhttp.open("POST",httpUrl,async);
		//发送合适的请求头信息
		xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); 
		xmlhttp.send(requestData); 
	}
}

2, call the method:

/*请求参数*/
var paramObj = {
	httpUrl : '',
	type : 'post',
	data : {
		name : 'sss',
		sex : '男'
	}
}
/*请求调用*/
httpRequest(paramObj,function(respondDada) {
    //这里编写成功的回调函数
    console.log(respondDada)
},function() {
	alert('网络错误')
});