AJAX返回值应用场景
1. 字符串:
- 短字符串:
应用场景: 一般返回较短,具有标志的字符串,如,0/1, succ/fail, 已注册,未注册等.
function chk() {
var xhr = new XMLHttpRequest();
var uri = '01.php?username=' + document.getElementsByTagName('input')[0].value;
xhr.open('get',uri,true);
xhr.onreadystatechange = function () {
if(xhr.readyState == 4) {
if(xhr.responseText == 1) {
alert('用户名已被占用');
} else if(xhr.responseText == 0) {
alert('用户名可用');
} else {
alert('异常错误');
}
}
};
xhr.send(null);
}$username = $_GET['username'];
$arr = array('zhangsan','lisi','wangwu');
echo in_array($username,$arr)?1:0;- Json格式字符串:
应用场景: 返回数组或对象等格式化数据
<h1>商品编辑</h1>
43 商品id：<input type="text" name="goods_id" onblur="mod();" /><br />
44 商品名称：<input type="text" name="goods_name" /><br />
45 商品价格：<input type="text" name="shop_price" /><br />
46 商品库存：<input type="text" name="goods_number" /><br />
47 <input type="submit" value="修改" />
9 function mod(){
10 var gid = document.getElementsByName('goods_id')[0].value;
11 var patt = /^\d+$/;
12 if(!patt.test(gid)){
13 alert('请输入正确的id');
14 return false;
15 }
16 var xhr = new XMLHttpRequest();
17 var uri = '05.php?goods_id=' +gid;
18 xhr.open('get',uri,true);
19 xhr.onreadystatechange = function(){
20 if(xhr.readyState == 4){
21 var rs = eval('('+xhr.responseText+')');
22 if(rs.errno != 0){
23 alert(rs.errstr);
24 return false;
25 }
26 document.getElementsByName('goods_name')[0].value = rs.name;
27 document.getElementsByName('shop_price')[0].value=rs.price;
28 document.getElementsByName('goods_number')[0].value=rs.number;
29 }
30 };
31 xhr.send(null);
32
33 }
1 <?php
2 $goods_id = $_GET['goods_id'] + 0;
3 if(!is_int($goods_id)){
4 $info = array('errno'=>1,'errstr'=>'id有误');
5 echo json_encode($info);
6 exit;
7 }
8 $conn = mysql_connect($host,$user,$pwd);
9 $sql = 'use **';
10 mysql_query($sql,$conn);
11
12 $sql = 'set names utf8';
13 mysql_query($sql,$conn);
14
15 $sql = 'select name,price,number from person where id ='.$goods_id;
16 $rs = mysql_query($sql,$conn);
17
18 $goods = mysql_fetch_assoc($rs);
19
20 //var_dump($goods);
21
22 if(empty($goods)){
23 $info = array('errno'=>2,'errstr'=>'无此商品');
24 echo json_encode($info);
25 }else{
26 $info = $goods;
27 $info['errno'] = 0;
28 $info['errstr'] = '正确';
29 echo json_encode($info);
30 exit;
31 }
- javascript object notation, javascript原生对象格式
- Html代码: 一整段html代码
应用场景: 当页面上有大块的数据变化时, 用数组要牵涉到大量的DOM操作,
这时,可以用PHP+Html,预先生成需要的html代码, 然后以字符串形式返回.
再innerHTML到页面中去.
9 function top3(type){
10 var xhr = new XMLHttpRequest();
11 var uri = '04.php?type='+type;
12 xhr.open('get',uri,true);
13
14 xhr.onreadystatechange = function(){
15 if(xhr.readyState == 4){
16 var rs = xhr.responseText;
17 document.getElementById('show').innerHTML = rs;
18 }
19
20 };
21 xhr.send(null);
22 }
23
24
25 </script>
26
27 <style type="text/css">
28 </style>
29 </head>
30 <body>
31 <input type="button" value="搞笑三人组" onclick="top3('is_fun');">
32 <input type="button" value="杀猪三人组" onclick="top3('is_pig');">
33 <input type="button" value="肌肉三人组" onclick="top3('is_ma');">
34
35 <div id="show">
36 </div>
37 </body>
38 </html>
1 <?php
2 $type = $_GET['type'];
3 if(!in_array($type,array('is_pig','is_ma','is_fun'))){
4 echo 'error';
5 exit;
6 }
7
8 $dbh = new PDO("$dbms:host=$host;dbname=$dbname",$user,$pwd);
9 $rs = $dbh->query("select id,name from person where $type = 1 limit 3");
10 $list = array();
11 while($row = $rs -> fetch(PDO::FETCH_ASSOC)){
12 $list[] = $row;
13 }
14 //var_dump($list);
15 ?>
16
17 <table border="1">
18 <tr><td>id</td><td>name</td></tr>
19 <?php foreach($list as $v) { ?>
20 <tr><td><?php echo $v['id'] ?></td><td><?php echo $v['name'] ?></td></tr>
21 <?php }?>
22
23
24
25
26 </table>
27
Jsonp:
2. XML
应用场景:返回大量的格式化数据时
如果返回XML来使用在客户端用 responseXML
- 服务器端的返回明确指定返回类型XML