从使用AJAX打开的页面访问父页面变量

问题描述：

i am looking for a way to directy access the variables of the page that loaded another page inside a div in it using ajax. i know i can do it using some kind of a get string pass it to the Javascript and open the son page with it and retrieve the variables using get normal GET function, i am looking for a better solution. i have this parent page:

<body onLoad="control_post_data(<?php
echo true;
//echo isset($_COOKIE['username']);  // allow after login is done
 ?>)">
<div id="publish_page">

</div>

and this is the script:

function control_post_data(bool){
var div = document.getElementById("publish_page");
var xmlhttp = createXmlHttpRequestObject();
if(bool){
    //user is registered presend post page
    xmlhttp.onreadystatechange=function()
    {
       if (xmlhttp.readyState==4 && xmlhttp.status==200)
       {

         var responseText = xmlhttp.responseText;

         div.innerHTML = responseText;
         //Use the response text to add the extra row
       }
    }
    xmlhttp.open("GET","sub_published.php",true);
    xmlhttp.send();
} else {
    //present log in/register page
    xmlhttp.onreadystatechange=function()
    {
       if (xmlhttp.readyState==4 && xmlhttp.status==200)
       {

         var responseText = xmlhttp.responseText;

         div.innerHTML = responseText;
         //Use the response text to add the extra row
       }
    }
    xmlhttp.open("GET","login.php",true);
    xmlhttp.send();
}
}

i am trying to acces the parent page variables in the sub_published.php page.

我正在寻找一种方法来直接访问在其中使用div加载另一个页面的页面的变量 ajax。 i知道我可以使用某种get字符串将它传递给Javascript并用它打开子页面并使用get normal GET函数检索变量，我正在寻找更好的解决方案。 i有这个父页面： p>

 ＆lt; body onLoad =“control_post_data（＆lt;？php 
echo true; 
 // echo isset（$ _ COOKIE ['username']）; /  /登录完成后允许
？＆gt;）“＆gt; 
＆lt; div id =”publish_page“＆gt; 
 
＆lt; / div＆gt; 
  code>  pre> 
 
 这是脚本： p> 
 
 
  function control_post_data（bool）{
var div = document.getElementById（“publish_page”）; 
var xmlhttp = createXmlHttpRequestObject（）; 
if  （bool）{
 //用户已注册presend post page 
 xmlhttp.onreadystatechange = function（）
 {
 if if（xmlhttp.readyState == 4＆amp;＆amp; xmlhttp.status == 200）
 {  
 
 var respo  nseText = xmlhttp.responseText; 
 
 div.innerHTML = responseText; 
 //使用响应文本添加额外的行
} 
} 
 xmlhttp.open（“GET”，“sub_published.php”  ，true）; 
 xmlhttp.send（）; 
} else {
 //存在登录/注册页面
 xmlhttp.onreadystatechange = function（）
 {
 if if（xmlhttp.readyState == 4＆amp;  ;＆安培;  xmlhttp.status == 200）
 {
 
 var responseText = xmlhttp.responseText; 
 
 div.innerHTML = responseText; 
 //使用响应文本添加额外的行
} 
}  
 xmlhttp.open（“GET”，“login.php”，true）; 
 xmlhttp.send（）; 
} 
} 
  code>  pre> 
 
  我试图访问sub_published.php页面中的父页面变量。 p> 
  div>

答

You could store all the parent page variables in the $_SESSION variable, like:

session_start();
$_SESSION['someid']['varname']=$var;

and then access it in the child page:

session_start();
$var=$_SESSION['someid']['varname'];

if you wish to allow users to have open multiple instances of your page with different values in variables, you should set the someid to something unique and send that with the ajax request, otherwise it can be static.

答

The simple answer is that you cannot. When the browser deals with the parent page, it has no knowledge of what/how generated it - all it sees is an HTML page, hence there are no variables of any kind that it knows about.

When you're invoking another PHP script using AJAX, the browser simply makes another call to the server. A new process is started on the server to run that script - and it has no knowledge of the parent page generation (which most likely has finished loading by now, anyway, and the script exited).

The only way to avoid using GET or POST values in the ajax request is to use cookies. You can set a cookie value (using setcookie() function) from the parent page and then read is in the ajax page (using $_COOKIE superglobal).

EDIT: Just realised the obvious: you can also use $_SESSION to store values between pages. See @Ratzor's answer for more info.

答

If you are talking about HTML then you can access the DOM-tree of a parent page via window.parent.document. If you are talking about PHP then it is not possible - I advise reading a bit more about client-server nature of PHP-HTML.

从使用AJAX打开的页面访问父页面变量

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