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This article mainly introduces the relevant information for sharing the three parsing modes of ajax. Friends who need it can refer to it
1. JSON format in Ajax
html code:
<html> <body> <input type="button" value="Ajax" id="btn"> <script> var btn = document.getElementById("btn"); btn.onclick = function(){ var xhr = getXhr(); xhr.open("post","10.php"); xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); /* * 在客户端如何构建JSON格式 * * 构建符合JSON格式的字符串 */ var user = '{"name":"zhangwuji","pwd":"123456"}'; xhr.send("user="+user); xhr.onreadystatechange = function(){ if(xhr.readyState==4&&xhr.status==200){ var data = xhr.responseText; /* * 使用eval()函数进行转换 * * 使用"()"将其包裹,eval()函数强制将其转换为JSON格式(javascript代码) * * 不使用"()"将其包裹,eval()函数将其识别为一个空的代码块 */ var json = eval("("+data+")"); console.log(json); } } } function getXhr(){ var xhr = null; if(window.XMLHttpRequest){ xhr = new XMLHttpRequest(); }else{ xhr = new ActiveXObject("Microsoft.XMLHttp"); } return xhr; } </script> </body> </html>
PHP code:
<?php // 接收客户端发送的请求数据 $user = $_POST['user']; // 就是一个JSON格式的string字符串 //var_dump($user); $json_user = json_decode($user,true); //var_dump($json_user['name']); $json = '{"a":1,"b":2,"c":3,"d":4,"e":5}'; //var_dump(json_decode($json)); // 响应数据符合JSON格式的字符串 // 1. 手工方式构建 //echo '{"name":"zhouzhiruo","pwd":"123456"}'; // 2. 使用json_encode()函数 echo json_encode($json_user); ?>
2 XML format in Ajax
html page:
<html> <body> <input type="button" value="Ajax" id="btn"> <script> var btn = document.getElementById("btn"); btn.onclick = function(){ // 实现Ajax的异步交互 var xhr = getXhr(); xhr.open("post","07.php"); xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); /* * 如何构建符合XML格式的请求数据 * * 注意 * * 请求数据的格式 - key=value 不能改变的 * * 将value值构建成符合XML格式的数据 * * 数据类型 - 字符串(string) * * 格式符合XML的语法要求 * * 编写注意 * * 定义变量 - 专门构建XML格式的数据 * * 在send()方法进行拼串 */ var user = "<user><name>zhangwuji</name><pwd>123456</pwd></user>"; xhr.send("user="+user); xhr.onreadystatechange = function(){ if(xhr.readyState==4&&xhr.status==200){ // 接收服务器端的响应数据 var xmlDoc = xhr.responseXML; var nameEle = xmlDoc.getElementsByTagName("name")[0]; var txtEle = nameEle.childNodes[0]; console.log(txtEle.nodeValue); } } } function getXhr(){ var xhr = null; if(window.XMLHttpRequest){ xhr = new XMLHttpRequest(); }else{ xhr = new ActiveXObject("Microsoft.XMLHttp"); } return xhr; } </script> </body> </html>
PHP page code:
<?php // 接收客户端发送的请求数据 $user = $_POST['user'];//符合XML格式要求的string类型 //var_dump($user); // 创建DOMDocument对象 $doc = new DOMDocument(); // 调用loadXML()方法 $result = $doc->loadXML($user); //var_dump($doc); // 如何构建符合XML格式的数据 /* 修改响应头的Content-Type值为"text/xml" header('Content-Type:text/xml'); echo $user;// 符合XML格式的string类型 */ header('Content-Type:application/xml'); echo $doc->saveXML(); ?>
三 HTML format in Ajax
HTML page:
<html> <body> <select id="province"> <option>请选择</option> <option>山东省</option> <option>辽宁省</option> <option>吉林省</option> </select> <select id="city"> <option>请选择</option> </select> <script> /* * 需要思考哪些事情? * * 在什么时候执行Ajax的异步请求? * * 当用户选择具体的省份信息时 */ // 1. 为id为province元素绑定onchange事件 var provinceEle = document.getElementById("province"); provinceEle.onchange = function(){ // 清空 var city = document.getElementById("city"); var opts = city.getElementsByTagName("option"); for(var z=opts.length-1;z>0;z--){ city.removeChild(opts[z]); } if(provinceEle.value != "请选择"){ // 2. 执行Ajax异步请求 var xhr = getXhr(); xhr.open("post","06.php"); xhr.setRequestHeader("Content-Type","application/x-www-form-urlencoded"); xhr.send("provcince="+provinceEle.value); xhr.onreadystatechange = function(){ if(xhr.readyState==4&&xhr.status==200){ // 接收服务器端的数据内容 var data = xhr.responseText; // data是字符串,转换为数组 var cities = data.split(","); for(var i=0;i<cities.length;i++){ var option = document.createElement("option"); var textNode = document.createTextNode(cities[i]); option.appendChild(textNode); city.appendChild(option); } } } } } // 定义创建XMLHttpRequest对象的函数 function getXhr(){ var xhr = null; if(window.XMLHttpRequest){ xhr = new XMLHttpRequest(); }else{ xhr = new ActiveXObject("Microsoft.XMLHttp"); } return xhr; } </script> </body> </html>
php page:
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<?php // 用于处理客户端请求二级联动的数据 // 1. 接收客户端发送的省份信息 $province = $_POST['provcince']; // 2. 判断当前的省份信息,提供不同的城市信息 switch ($province){ case '山东省': echo '青岛市,济南市,威海市,日照市,德州市'; break; case '辽宁省': echo '沈阳市,大连市,铁岭市,丹东市,锦州市'; break; case '吉林省': echo '长春市,松原市,吉林市,通化市,四平市'; break; } // 服务器端响应的是字符串 ?>The above is what I compiled for everyone. I hope it will be helpful to everyone in the future. help. Related articles:
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