CODEWITHSUNDEEP
javawicket
Rajani Sohoni
Rajani Sohoni

Reputation: 15

How to stop wicket-9 from throwing StalePageException

Wicket throws StalePageException only if some Ajax action has been performed on a page before duplicating the page.

Example wicket project can be found at, along with steps to reproduce the exception.

https://github.com/rjngshn/java-wicket-testing/tree/main

Is there a way to ensure this exception is not thrown?

Thanks

Rajani

Upvotes: 1

Views: 490

Answers (1)

martin-g
martin-g

Reputation: 17503

The default behavior provided in Wicket is too queue AJAX requests as they come in. Let’s say you have a button with a callback that does some work when clicked and updates the UI. This means that if the button is quickly clicked three times successively, the last two requests will be queued up and processed after the first request finishes.

A simple solution is to change the behavior of the AjaxChannel from queueing to active. This means that if any AJAX requests are received while there is an active(unfinished) request being processed, they will be ignored.

So how do we override Wicket’s default behavior in one spot and ensure all AjaxChannel‘s are modified? We use a custom AjaxRequestTarget.IListener.

public class ActiveAjaxListener implements AjaxRequestTarget.IListener {
 
 private static final AjaxChannel ACTIVE_CHANNEL = new AjaxChannel(AjaxChannel.DEFAULT_NAME, AjaxChannel.Type.ACTIVE);

 @Override
 public void updateAjaxAttributes(AbstractDefaultAjaxBehavior behavior, AjaxRequestAttributes attributes) {
    attributes.setChannel(ACTIVE_CHANNEL);
 }
}

Our ActiveAjaxListener class will modify every AJAX behavior and make sure it uses the active channel. To register it, we simple insert this line into our WebApplication init() method:

getAjaxRequestTargetListeners().add(new ActiveAjaxListener());

(I've copied this explanation from https://www.coderdreams.com/wicket-quick-tip-4-change-default-ajaxchannel-to-active/)

Another way is to use a veil that prevents the double clicks via JS/CSS. More details about this approach could be found at JavaScript / Wicket : How to display an overlay which prevents user interaction

Upvotes: 2

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