长沙北大青鸟作者:科泰校区guestzzz
原文:
Avoid multiple form submissions
Submitted By: Douglas E. Cook
Date: 07/26/00 19:46
Does your database suffer from "duplicate post" syndrome? The cure isn't too difficult. Here is a simple way to prevent users from submitting the same form multiple times.
First, declare a session variable to store a serial number for each form. I call mine "$userLastAction." Then, in every form where duplicate submission is a problem, include a hidden field, and set the value to $userLastAction+1:
<INPUT TYPE=HIDDEN NAME=lastAction VALUE=<?= $userLastAction+1 ?>>
Finally, verify that the form has not been previously submitted before acting on the submission:
if($lastAction>$userLastAction and inputIsValid(...)){
$userLastAction++; // Increment serial number
// Act on form here
}
译自:phpbuilder
这只是一个小技巧,用来避免一个表单的重复提交。这样多少可以防止一些灌水的现象,另外有时候由于网络状况等原因用户不知道提交是否成功,也会再次提交同一份表单。
这个技巧的主要原理是不允许用户回退后再次提交,也就是说回退后修改再提交也是不允许的,而且也不能避免Ctrl-C/Ctrl-V的灌水办法。究竟有没有用,还是看各位站长的喜好了。