Thank you Craig, I see the point, You are right it makes a lot of sense. But the behind the scene matter of my question was the performance reason. I have to copy all the properties of ActionForm to appropriate business logic object. The clean way of doing this is using the reflection API, which is rather slow.
regards Wojtek ----- Original Message ----- From: "Craig R. McClanahan" <[EMAIL PROTECTED]> To: "Struts Developers List" <[EMAIL PROTECTED]>; "box" <[EMAIL PROTECTED]> Sent: Sunday, November 25, 2001 7:14 AM Subject: Re: General model question ? > > > On Thu, 22 Nov 2001, box wrote: > > > Date: Thu, 22 Nov 2001 19:36:25 +0100 > > From: box <[EMAIL PROTECTED]> > > Reply-To: Struts Developers List <[EMAIL PROTECTED]>, > > box <[EMAIL PROTECTED]> > > To: [EMAIL PROTECTED] > > Subject: General model question ? > > > > Hi everybody, > > > > I am new to struts, but I find them very usefull. > > > > There is one question that bothers me. > > > > Wy is ActionForm a class not an interface ? > > > > I have got my own application data model and I would just need to > > implement > > the ActionForm to update/input the data via html forms. > > > > But it's not possible - I must inherit the struts structure, so I have to > > create ActionForm with get, set methods and after all copy all properties > > between my data model and the corresponding ActionForm. > > > > Am I missing something ? > > > > ActionForm is a class in order to *prevent* exactly the behavior you > propose :-). > > The purpose of an ActionForm is to contain the server-side state of the > input fields, for the following reasons: > > * So that you can validate them (you don't want invalid data > being scribbled into your application data objects by Struts's > automatic bean population) > > * So that you can reproduce the user's input data in case of an > error such as an invalid integer (you would use a String in the > ActionForm for an EJB property that is an "int"). > > * So that your application data objects can be reused in non-Struts > contexts (otherwise, they would always require struts.jar to be around). > > You *really* don't want to modify anything in your application data model > until *after* validation has succeeded. That's why the Struts design > pattern is to do this in an Action, by copying the appropriate values from > the ActionForm into your application data objects, performing any data > conversions that are necessary. Making ActionForm a class instead of an > interface forces you to do the right thing. > > > regards > > > > Wojtek > > > > Craig McClanahan > > > -- > To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> > For additional commands, e-mail: <mailto:[EMAIL PROTECTED]> > > > -- > Myslisz o otworzeniu wlasnego sklepu internetowego? > A moze o wynajeciu stoiska w wirtualnym pasazu? > W Centrum e-biznesu mozesz miec jedno i drugie. Juz od 290 zl za rok. > Wybierz: e-witryne lub e-sklep. http://handel.getin.pl/ > > -- Myslisz o otworzeniu wlasnego sklepu internetowego? A moze o wynajeciu stoiska w wirtualnym pasazu? W Centrum e-biznesu mozesz miec jedno i drugie. Juz od 290 zl za rok. Wybierz: e-witryne lub e-sklep. http://handel.getin.pl/ -- To unsubscribe, e-mail: <mailto:[EMAIL PROTECTED]> For additional commands, e-mail: <mailto:[EMAIL PROTECTED]>
