I've only seen this type of behavior if I have an empty <img src=""/> element or something similar.
On Mon, Jun 25, 2012 at 11:45 AM, Ian Marshall <[email protected]>wrote: > Hello All, > > My web application uses the default request cycle render strategy > IRequestCycleSettings.RenderStrategy.REDIRECT_TO_BUFFER. > > An external web site calls a web page on my web application using a URL > with > page parameters (all of which I set before I hand over to the external web > site). I find that the relevant WebPage constructor gets called twice > during > the request-response process, which I presume is expected behaviour: once > to > handle the action part of the request, again to handle the render part of > the request. > > In the past, I bypassed this issue by showing an option with an "OK" button > for action, so it didn't matter if the page constructor was called twice; > no > persistence code got executed until the user clicked "OK" subsequently. > > Now, however, I need to act on the request from the external web site > straight away, in order to ensure that the database is updated before the > user moves to another page without clicking "OK" (or away from my > application altogether). Currently, I code this to happen in the page's > constructor, so my database persistence code get called twice too. Not > good, > especially with Google App Engine, which does not like rapid updating of > the > same persistent "entity group". > > My question is: is there a (simple) way for me to know whether my page is > being constructed during the action part of the request as opposed to the > render part of the request? > > (I have a work-around in mind, which is to store relevant details in the > session, and use a check on these to prevent a second database persistence > operation for the same data, but I would have thought that a simpler, more > direct solution exists.) > > Any hints would be greatly appreciated. > > > MY DEVELOPMENT ENVIRONMENT > Web framework: Wicket 1.5.7 > Java: 1.6.0_33; Java HotSpot(TM) Client VM 20.8-b03 > Web server system: Google App Engine for Java version 1.6.6 > Operating system: Microsoft Windows XP Home Edition version 2002 SP3 > (version 5.1 running on x86; Cp1252; en_GB) (nb) > IDE: NetBeans IDE 7.1.2 (Build 201204101705) > > > Ian Marshall > > -- > View this message in context: > http://apache-wicket.1842946.n4.nabble.com/Wicket-Page-constructor-getting-called-twice-tp4650225.html > Sent from the Users forum mailing list archive at Nabble.com. > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [email protected] > For additional commands, e-mail: [email protected] > >
