這個技巧的主要原理是不允許用戶回退後再次提交,也就是說回退後修改再提交也是不允許的,而且也不能避免Ctrl-C/Ctrl-V的灌水辦法。究竟有沒有用,還是看各位站長的喜好了
你是否遇到過“重復提交”的問題?要解決這個問題其實並不難。這裡有一個簡單的方法避免同一表單的重復提交。
首先,我們可以定義一個session變量用來保存一個表單的提交序列號。這裡我定義為“$userLastAction”。然後在表單裡加入一個hidden變量,把值設為$userLastAction+1:
<input type=Hidden name=lastAction value=<? =$userLastAction+1 ?>>
最後,在處理提交之前判斷表單是否已被提交過:
if($lastAction>$userLastAction and inputIsValid(...)){
$userLastAction++; // 序列號加1
// 處理表單數據
}
原文:
Avoid multiple form submissions
Submitted By: Douglas E. Cook
Date: 07/26/00 19:46
Does your database suffer from "duplicate post" syndrome? The cure isn't too difficult. Here is a simple way to prevent users from submitting the same form multiple times.
First, declare a session variable to store a serial number for each form. I call mine "$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
}