Introduction
Joe was doing online shopping, he clicked the Submit button to place an order, there was no response for 5 seconds, he thought something had gone wrong and clicked the button again!
What happened?
Joe probably got charged twice!! It was only because he could not receive the response for whatever reason, but the sever got two requests from him and placed duplicate orders for him.
Here is a solution which can prevent such kind of mistakes.
Background
Basically, this is a .NET implementation of the SynchronizerToken pattern which has been used in the Java world for years (refer to Core J2EE Patterns).
Using the code
It is pretty easy to use:
- add a reference to the
SynchronizerToken
assembly in your project.
- inherit you page from the
Synchronizer
page.
- add the
[OneSubmitOnly]
attribute right before your page class.
[OneSubmitOnly(RedirectURL = "~/ErrorPage.aspx")]
public class WebForm1 : Synchronizer
{
.......
}
Points of Interest
- The
OneSumbmitOnly
attribute has an optional RedirectURL
property which points to any valid URL to where a request gets redirected when duplicated submission happens. If no RedirectURL
property is set, the request gets rejected and the default message will show up.
- Resubmission is checked before any subclass event.
History
- Version: 1.0
- Creation date: 2005-09-30
- Version: 1.1