Hi Bill, so you say, it is good practice to use the two forms in one action as I do in my current solution? Sure, one has to hide the internals from AF1 to an action primarily designed to use AF2 to keep the address module generic. Perhaps I should make the calling ActionForms implement a specific interface. If I really want a fully generic address module I would have to split the action(s) in two, simply because the actions designed for the address module need a generic API. I cannot rely (for full genericity) on a "calling" module to use AF1. In my current situation I will probably ignore this as it is a straightforward refactoring which can be done when need occurs. As to the question request vs. session scope I understand the problems which might occur using session scope. I do not see a solution which would also fulfil the modularization requirement.
Thanks! Martin > -----Ursprüngliche Nachricht----- > Von: Bill Keese [mailto:[EMAIL PROTECTED] > Gesendet: Dienstag, 16. November 2004 02:10 > An: Struts Users Mailing List > Betreff: Re: AW: using multiple action forms in one action. > Best practice? > > > Hi Martin, > > > From this JSP I want to access a (hopefully) generic module > to get the > > access points. This "module" has to get some information (e. g. a > > region to prefilter the addresses or access points already > existing) > > from JSP1. > > > I think you should generate the input to the generic module, rather > than passing the ActionForm directly: > > // get data from ActionForm1 needed to look up addresses > AddressLookupInfo info = getAddressInfoFromActionForm1(AF1); > > // lookup addresses > List res = AddressLookup.getAddresses(info); > ... > > Then your module can still be generic. > > > I could take the necessary information from AF1 to some > POJO (or bean) > > on model level (or controller level) and transfer it to > AF2. This is > > probably the "cleanest" solution but means to split each > action into > > two, just to do > > the data transfer. > > > > > You shouldn't need to split each action into two. Action1's > job is to > handle the input from ActionForm1, and then do the setup to display > JSP2, right? So, just create the ActionForm2 manually inside Action1: > > // Create AF2 as an input/output form > ActionForm2 af2 = new ActionForm2(); > session.setAttribute("actionForm2", af2); > > // ... and pre-populate it with the data the user has already input > ActionForm1 af1 = > (ActionForm1) getActionForm(mapping, form, > request, session); > af2.loadDataFromAF1(af1); > > // forward control to JSP2 > return (mapping.findForward("jsp2")); > > > My current solution simply accesses both action forms, AF1 and AF2 > > (getting > > the one not available as the "form"-parameter by MyForm mf = > > (MyForm)session.getAttribute("AFi"); > > but my feeling is that this is not really good style. > > > > > I guess it depends on whether you consider the two forms to represent > one logical command or two logical commands. > > The other thing to consider, though, is whether or not you > want to store > the ActionForms at session scope. Session scope is > problematic because > you might end up accessing old data (if the user previously > quit in the > middle of a wizard). Also, I imagine things would fail in a > distributed > application where the user's requests are randomly routed to multiple > servers. The alternative is to use request level scope, > but in this > case the information entered in Form#1 has to be embedded in > the output > of JSP2 as hidden HTML variables. > > Bill > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
