Javascript封装原生ajax请求

function ajax() {
var param = {
url: arguments[0].url || '',
type: arguments[0].type || "Get",
data: arguments[0].data,
dataType: arguments[0].dataType || "json",
contentType: arguments[0].contentType || "application/x-www-form-urlencoded",
async: arguments[0] || true,
beforSend: arguments[0].beforeSend || function () { },
success: arguments[0].success || function () { },
error: arguments.error || function () { },
complete: arguments[0].complete || function () { }
}
param.beforSend();
var xmlhttpRequest = createHttpRequest();
xmlhttpRequest.responseType = param.dataType;
xmlhttpRequest.open(param.type, param.url, param.async);
xmlhttpRequest.setRequestHeader("Content-Type", param.contentType);
xmlhttpRequest.send(converData(param.data));
xmlhttpRequest.onreadystatechange = function () {
if (xmlhttpRequest.readyState === 4) {
if (xmlhttpRequest.status === 200) {
param.success(xmlhttpRequest.response);
} else {
param.error();
}
param.complete();
}
}
}
//创建请求对象
function createHttpRequest() {
if (window.ActiveXObject) {
return new ActiveXObject("Microsoft.XMLHTTP");
} else if (window.XMLHttpRequest) {
return new XMLHttpRequest();
} else {
return null
}
}
//解析请求参数
function converData(dataPar) {
if (typeof dataPar === 'object') {
var result = "";
for (var i in dataPar) {
result += i + '=' + dataPar[i] + "&"
}
result = result.substring(0, result.length - 1);
return result;
} else {
return dataPar;
}
}