This time I will show you how ajax implements network request encapsulation. What are the precautions for ajax to implement network request encapsulation. The following is a practical case, let's take a look.
Example code:
// 封装的ajax网络请求函数 // obj 是一个对象 function AJAX(obj){ //跨域请求 if (obj.dataType == "jsonp") { //在这里 callback 必须是全局变量 保证函数消失的时候 这个变量不可以被销毁 //处理一下函数名(防止多个网络请求 函数名字相同 出现紊乱的情况) var hehe = "callBack" + "_" + new Date().getTime() + "_" + String(Math.random()).replace(".",""); window[hehe] = obj.success; //创建 script标签 var sc = document.createElement("script"); sc.src = obj.url + "?" + "cb=" + hehe; console.log(sc.src); document.body.appendChild(sc); document.body.removeChild(sc); return; } //1、创建 ajax 对象 var ajaxObj = null; if (window.XMLHttpRequest) { ajaxObj = new XMLHttpRequest(); }else{ ajaxObj = new ActiveXObject("Microsoft.XMLHTTP"); } //设置请求的类型 obj.type = obj.type.toUpperCase() || "GET"; //如果是get请求 并且需要传递参数 则需要给 url 后面拼接参数 if (obj.type == "GET") { var arr = [];//定义数组 用于把对象存储到数据里面 for (var key in obj.data) { arr.push(key +"="+ obj.data[key]); } //用&分隔数组 让其转化为类似:name=lxl&age=18 的形式 var str = arr.join("&"); obj.url = obj.url +"?"+ str; //拨号 ajaxObj.open(obj.type,obj.url,true); //发送"name=123&age=18" ajaxObj.send(); }else{ var arr = [];//定义数组 用于把对象存储到数据里面 for (var key in obj.data) { arr.push(key +"="+ obj.data[key]); //console.log(arr); } //用&分隔数组 让其转化为类似:name=lxl&age=18 的形式 var str = arr.join("&"); //console.log(str); ajaxObj.open(obj.type,obj.url,true); ajaxObj.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); ajaxObj.send(str); } //监听 ajaxObj.onreadystatechange = function(){ if (ajaxObj.readyState == 4) { if (ajaxObj.status >= 200 && ajaxObj.status < 300 || ajaxObj.status == 304) { //请求成功 obj.success(ajaxObj.responseText); }else{ //请求失败 obj.error(ajaxObj.status); } } } }
I believe you have mastered the method after reading the case in this article. For more exciting information, please pay attention to other related articles on the PHP Chinese website !
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