Ajax Gets the page cached solution _ajax related

In this case, the native cache is checked first for Ajax acquisition, and if the native cache already has the same content, the remote server is not accessed. Such operations can improve speed and reduce server pressure. But the drawbacks are also obvious.

To solve this problem. We must add an extra parameter to the Fetch page. The simpler approach is to use a random number.

Examples are as follows

Copy Code code as follows:

function Idcheck () {//Parameter call functions
var f = document.modify_form;
var book_num = F.book_num.value;
if (book_num== "") {
Window.alert ("Book Number cannot be empty");
F.book_num.focus ();
return false;
}
Add a random number//////////////////////////////
var number = Math.random ();
Number = number * 1000000000;
Number = Math.ceil (number);
//////////////////////////////////////////
Send_request (' get_book.php?book_num= ' +book_num+ ' &ranum= ' +number); The "Ranum=number" in the back is a bonus.
}

This avoids the problem of returning the same content to the same parameter page.

There is also a way to add code to the page that is called to prevent this page from being cached

HTM Web page

Copy Code code as follows:

<metahttp-equiv= "Pragma" content= "No-cache" >
<metahttp-equiv= "Cache-control" content= "No-cache,must-revalidate" >
<metahttp-equiv= "Expires" content= "WED,26FEB199708:21:57GMT" >

or <metahttp-equiv= "expires" content= "0" >
ASP Web page

Copy Code code as follows:

Response.expires=-1
Response.expiresabsolute=now ()-1
Response.cachecontrol= "No-cache"

PHP Web page

Copy Code code as follows:

Header ("Expires:mon,26jul199705:00:00gmt");
Header ("Cache-control:no-cache,must-revalidate");
Header ("Pragma:no-cache");

JSP Web page

Copy Code code as follows:

Response.AddHeader ("Pragma", "no-cache");
Response.AddHeader ("Cache-control", "no-cache,must-revalidate");
Response.AddHeader ("Expires", "0");