Question

我想定期对服务器进行AJAX调用，服务器脚本（PHP）应该创建一个新的XML文件。然后，XML文件由另一个javascript函数读取并显示在网页上。我该如何做到这一点？继承了我的Jquery代码：

setInterval(
    function(){
        $.Ajax({url: 'register.php'});}, 5000
    );

正在请求的PHP代码：

session_start();
$user = $_SESSION['username'];
$uID = $_SESSION['UserID'];
$host="127.0.0.1:3306";
$db_name='wf_db';
$tbl_name="tasks";
$connect = new mysqli("$host","root"," ","$db_name")or die('Can\'t connect to database!');
$sql = "SELECT * FROM $tbl_name WHERE UserID='$uID' and Task_Completed='0'";
$query_data = mysqli_query($connect,$sql)or die('Couldnt get data');
$row = mysqli_num_rows($query_data);
chmod("result".$uID.".xml", 0755);
if($row != 0){ 
    $file = fopen("result".$uID.".xml",'w')or die("Cannot Open File");
    $_xml = "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\r\n";
    $_xml .="<tasks>\r\n";
    while ($result = mysqli_fetch_array($query_data)) {
         if ($result["TaskID"]) {
            $_xml .="\t<task>\r\n";
            $_xml .="\t\t<AssignDate>" . $result["Assign_Date"] . "</AssignDate>\r\n";
            $_xml .="\t\t<TaskID>" . $result["TaskID"] . "</TaskID>\r\n";
            $_xml .="\t\t<TaskSubject>" . $result["Task_Subject"] . "</TaskSubject>\r\n";
            $_xml .="\t\t<Notes>" . $result["Notes"] . "</Notes>\r\n";
            $_xml .="\t</task>\r\n";
         } else {
            $_xml .="\t<task title=\"Nothing Returned\">\r\n";
            $_xml .="\t\t<AssignDate>none</Assign_Date>\r\n";
            $_xml .="\t\t<TaskID>none</TaskID>\r\n";
            $_xml .="\t\t<TaskSubject>none</TaskSubject>\r\n";
            $_xml .="\t\t<Notes>none</Notes>\r\n";
            $_xml .="\t</task>\r\n";
         }
    }

 $_xml .="</tasks>";

 fwrite($file, $_xml);

 fclose($file);

 } 
 else {
    echo 'Oops something went wrong!';
}

这是我到目前为止，我错过了什么？我是PHP和AJAX的新手，因此代码中可能存在错误。

Answer 1

尝试使用setTimeout JS函数进行调用。

var T = setTimeout("myAjaxFunction");

function myAjaxFunction(){
  //do what you want.
  $.ajax({...});
}

Answer 2

像

一样进行ajax调用

setInterval(
    function(){
        $.ajax({ 
         url: 'register.php',
         type:'GET',
         dataType:'text/xml',
         success:function(xml){
         //here is your xml sent from the server
         //parse it using $.parseXML
         //then manipulate it according to your will

         },
         error:function(jxhr){//error handler that will be called if something goes wrong
         console.log(jxhr.responseText);

         }//error handler ends
        });//ajax call ends
   }, 5000);

这里有一些你必须研究的有用链接

$.parseXML

Using jQuery to parse XML returned from PHP script (imgur.com API)

Parsing XML from php using jquery

AJAX调用服务器定期生成XML

2 个答案: