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https://issues.apache.org/jira/browse/WICKET-5810?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Martin Grigorov resolved WICKET-5810.
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    Resolution: Not a Problem

Page#setVersioned(false) is an *instance* method saying that this page instance 
won't have several versions.
If you click on a link that creates a new instance of this page class then the 
new instance has nothing to do with the previous one.
This is the design.
Other frameworks (Tapestry 5.0/5.1) have tried to do what you suggest but they 
faced problems with this approach.

At https://github.com/martin-g/single-page-instance you may find an attempt to 
do something similar - one instance per page type per session, ignoring 
#setVersioned(). Read http://markmail.org/message/ofyvgybcjp5cvf75 for the 
discussion about it and the problems found with it so far.

> Component#setVersioned(false) should force singleton component instance per 
> session
> -----------------------------------------------------------------------------------
>
>                 Key: WICKET-5810
>                 URL: https://issues.apache.org/jira/browse/WICKET-5810
>             Project: Wicket
>          Issue Type: Improvement
>          Components: wicket
>    Affects Versions: 6.16.0
>         Environment: N/A
>            Reporter: bernard
>         Attachments: NullVersionedPanelReplacement.zip
>
>
> This is a follow-up issue from issue WICKET-5693.
> I am for now dropping from my requirement the provision of a mapper that does 
> not show the version number in the URL, for the reason that this seems to 
> complicate the discussion, not for the reason that I don't need it.
> Instead I am focusing on the essential requirement to prevent double submits 
> which should never happen if a stateful page was truly non-versioned in the 
> session scope, and the latest page instance cannot process a submit request. 
> We can discuss the URL issue later.
> To keep my use case simple, I am creating a basic implementation of a page 
> where the user replaces an old panel with a new one. Once this panel is 
> replaced, the user should not be given the chance to access any page version 
> containing the old panel.
> Only then, IMHO, would the contract of Component#setVersioned(false) be fully 
> implemented.
> When executing the attached test case as a web app, one finds that after 
> panel replacement with the new panel, it is possible to display the page 
> having the version containing the old panel by clicking on the original link 
> to the page.
> It appears that Wicket just starts fresh and forgets that the current version 
> of the page contains the new panel not the old one. It creates new version 
> numbers - however I am not saying that the numbers reflect the number of 
> versions in the session. I understand that most likely only a single version 
> exists.
> I was surprised to find in the "Apache Wicket Cookbook" 
> http://www.packtpub.com/apache-wicket-cookbook/book
> in recipe0203 a complex method to prevent double submits via the old J2EE 
> server token pattern. I was thinking that Wicket, supporting server side 
> component state, actually provides the token via a non-versioned page 
> instance (singleton per session) out of the box. I hope that it is not be too 
> late to implement this essential feature by addressing this Jira issue.
> I acknowledge that panel replacement may have its own issues, but it is 
> useful in a testcase, demonstrating component state. One could simply add a 
> server token to the page instance and process any request depending on it.



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