Two Methods for page rollback supported by PHP

During the development process, the information filled in when the page is returned due to a form error is often lost. To support page Jump, you can use two methods.
First, use the header method to set the message header cache-control

Header ('cache-control: private, must-revalidate'); // supports page Jump back

Second, use the session_cache_limiter method.

// Note that it should be written before the session_start method.
Session_cache_limiter ('Private, must-revalidate ');

PS: cache-Control Message Header domain description
Cache-control specifies the cache mechanism that requests and responses follow. Setting cache-control in a request message or response message does not modify the cache processing process of another message. The cache commands in the request include no-cache, no-store, Max-age, Max-stale, Min-fresh, only-if-cached, commands in the Response Message include public, private, no-cache, no-store, no-transform, must-revalidate, proxy-revalidate, and Max-age. The instructions in each message are as follows:

Public indicates that the response can be cached in any cache area.
Private indicates that the whole or part of the response message of a single user cannot be processed by the shared cache. This allows the server to only describe part of the user's response message, which is invalid for requests of other users.
No-Cache indicates that the request or response message cannot be cached.
No-store is used to prevent the unintentional release of important information. Sending a request message does not cache the request and response messages.
Max-age indicates that the client can receive responses with a lifetime not greater than the specified time (in seconds.
Min-fresh indicates that the client can receive a response whose response time is earlier than the current time plus the specified time.
Max-stale indicates that the client can receive response messages beyond the timeout period. If the value of the Max-stale message is specified, the client can receive response messages that exceed the timeout period.

 

Reference Source: http://17drupal.com/node/7193