[seam-dev] Re: [Richfaces-exadel] Concurrent requests (event queue and errorcondition)

RichFaces (A4J) allows to alter the default error message or default error handling. In case of session expiration, the alert box is shown and then the redirect is performed, by default. Default error message shown in the box is: AJAX_VIEW_EXPIRED=View state could't be restored - reload page ? Developer can alter it defining AJAX_VIEW_EXPIRED key in the message bundle. If another than showing alert box behaviour is required, developer can alter the error handler like that: A4J.AJAX.onExpired = function(loc,expiredMsg){ // Custom Developer Code }; Where: loc is a URL of the current view expiredMsg - the message defining with AJAX_VIEW_EXPIRED key. ----- Original Message ----- From: "Pete Muir" <pmuir(a)redhat.com&gt; To: "Pete Muir" <pmuir(a)redhat.com&gt; Cc: "Shane Bryzak" <shane.bryzak(a)jboss.com>; "JBoss Seam Development List" <seam-dev(a)lists.jboss.org>; "Prakasha Aradhya" <paradhya(a)redhat.com>; "Rodney Russ" <rruss(a)redhat.com>; "Ted Goddard" <ted.goddard(a)icesoft.com>; <richfaces-exadel(a)redhat.com>; "Judy Guglielmin" <jguglielmin(a)icesoft.com&gt; Sent: Tuesday, September 02, 2008 2:22 PM Subject: Re: [Richfaces-exadel] Concurrent requests (event queue and errorcondition) > > On 2 Sep 2008, at 19:49, Pete Muir wrote: > >> >> On 2 Sep 2008, at 19:19, Ted Goddard wrote: >> >>> >>> Hi Pete, >>> >>> The ICEfaces bridge can handle errors to various Ajax responses; for >>> instance, >>> in some cases the icon in the connection status component will be >>> changed to >>> reflect an error response. >> >> Ok, this is good - means that it should work as it is today with >> IceFaces. >> >> Seam requires a bit of a rejig to make it do this, so I'll work on that >> next. > > So, Seam now throws an exception when it can't serialize a concurrent > request, and you can use Seam's standard exception handler to translate > that into the appropriate response (e.g. redirect to an error page, send > an http error code). > > I've tested A4Js error handling, and it all works well (e.g. you can pop > up a message to the user). > > Shane, can Seam remoting deal with an HTTP error being sent to it? > > The changes the user will need to make: > > 1) Define the exception handling in pages.xml to either send an HTTP > error or go to an error page. Sending a 503 error with logging turned off > will be the recommended approach. > 2a) A4J: alter their templates to override the A4J error handling > 2b) ICEfaces: ??? (do nothing by the sound of it) > 2c) Seam Remoting: ??? > > Currently the system boots them out of the conversation, we replace that > with throwing an exception, both are equally bad so this shouldn't be too > much of regression for existing apps. > >>> So responding with an error to the Ajax request sounds good ... the >>> question is >>> how it should be displayed to the user. Or should this error cause a >>> retry >>> over Ajax after some period of time (and not be displayed to the user >>> immediately)? >> >> I think both these are reasonable options, and should be up to the >> developer to choose one. I would say the default behaviour should be to >> display a message to the user. > > Thanks! > >> >> >>> >>> >>> Regards, >>> Ted. >>> >>> On 2-Sep-08, at 12:06 PM, Pete Muir wrote: >>> >>>> Ted, Judy, Shane, >>>> >>>> I've recently been working on >>>> https://jira.jboss.org/jira/browse/JBSEAM-1832 and am trying to define >>>> better what Seam should do when it cannot successfully serialize >>>> requests to the conversation scope (because the queue times out). My >>>> preferred solution is to drop the request, and send an error to the >>>> browser for it to deal with. I'm looking for your input on the best >>>> way to send such an error that will work with different remoting/ajax >>>> frameworks. >>>> >>>> A couple of points >>>> >>>> 1) Should work ootb - the user should just get some error message in >>>> the browser by default, which they can customize >>>> 2) Should work the same for all different JS frameworks >>>> >>>> Having looked at A4J, I notice that it can handle being sent an HTTP >>>> error. Semantically, it seems correct to approach it this way >>>> (specifically sending a 503) but if we do that, we need a way for (at >>>> least) Seam Remoting, A4J and IceFaces to intercept that request and >>>> translate it to a message to the user (and not bring up an ugly error >>>> message). We can send a detailed error message as the body of the >>>> message (e.g. concurrent request) and perhaps add a http header that >>>> shows where this error comes from. >>>> >>>> WDYT? >>>> >>>> On 2 Sep 2008, at 18:55, Pete Muir wrote: >>>> >>>>> Seam serializes, also using a timed queue. We need to do *something* >>>>> when the event reaches the timeout. Currently, Seam will make the >>>>> active conversation inactive, which isn't the best behaviour, and I >>>>> think the correct approach is to stay in the conversation, but to >>>>> send an error. I took a look at the A4J error handling, and it looks >>>>> like the best approach is to send an Http error to the browser, which >>>>> can then be intercepted and handled? Can we provide a default >>>>> behaviour for this? >>>>> >>>>> Thanks, >>>>> >>>>> Pete >>>>> >>>>> _______________________________________________ >>>>> Richfaces-exadel mailing list >>>>> Richfaces-exadel(a)redhat.com >>>>> https://www.redhat.com/mailman/listinfo/richfaces-exadel >>>> >>> >>> >>> _______________________________________________ >>> Richfaces-exadel mailing list >>> Richfaces-exadel(a)redhat.com >>> https://www.redhat.com/mailman/listinfo/richfaces-exadel >> > > _______________________________________________ > Richfaces-exadel mailing list > Richfaces-exadel(a)redhat.com > https://www.redhat.com/mailman/listinfo/richfaces-exadel