How to retain the filled-in information after PHP fails to submit the form_PHP Tutorial

This article will introduce to you some summary methods on how to retain the filled-in information after PHP fails to submit the form. The most commonly used method is to use caching. This method may cause problems if the network speed is slow. The best way is to use ajax. .

1． Use the header header to set the cache control header Cache-control.

PHP code
1.

tr>

The code is as follows

Copy code

header('Cache-control: private, must-revalidate'); //Support page bounce

代码如下	复制代码
header('Cache-control: private, must-revalidate'); //支持页面回跳

2． Use the session_cache_limiter method.

PHP code

The code is as follows

Copy code

1.session_cache_limiter('private, must-revalidate'); //Write before the session_start method

代码如下	复制代码
1.session_cache_limiter('private, must-revalidate'); //要写在session_start方法之前

The following is an introduction to the session_cache_limiter parameters:

The meaning of several parameters in session_cache_limiter is:
nocache: Of course it is not cached (for example: the form information is cleared), but public variables can be cached
private: private mode cache (for example: form information is retained, but valid within the lifetime)
private_no_cache: private mode but does not expire (form information is retained)
publice: public mode, (form information is also retained Reserved)

Set cache expiration time: session_cache_expire function setting, the default is 180 minutes.

Commonly encountered problems:

1. session_cache_limiter("private"); The form information is retained, but if I modify the submitted information, the information presented on the form page is still the information in the cache, which cannot be automatically refreshed in time. If session_cache_limiter("private"); is not used, it cannot Retain form information

Solution:

Add

The code is as follows

Copy code

代码如下	复制代码
session_cache_limiter( "private, must-revalidate" );即可

session_cache_limiter( "private, must-revalidate" ); That's it

Another way we can use ajax to instance

index.html template file large content:

The code is as follows	Copy code
Enter name: Enter password: ajax submission postsubmit getsubmit

There seems to be a bug in the original source code, but it runs normally after modification.

Contents of the login.php file:

?>

The code is as follows

代码如下	复制代码
echo json_encode(array ('username'=>$_REQUEST['username'],'password'=>$_REQUEST['password'])); ?>

Copy code

echo json_encode(array ('username'=>$_REQUEST['username'],'password'=>$ _REQUEST['password']));

In this case, we don’t need to refresh the page when submitting. If it fails, there will be a submission directly, which is 100% The data will not be lost after the save and submit fails.

http://www.bkjia.com/PHPjc/444583.htmlwww.bkjia.comtrue

http: //www.bkjia.com/PHPjc/444583.html

TechArticle

This article will introduce to students how to retain the filled-in information after PHP fails to submit the form. Some methods are summarized, the most commonly used Just use caching. This method may be possible if the network speed is slow...