Good point. And default/auto construction issue illuminates a design concern.
Currently -- as I understand it -- the ActionForm (bean) is populated by the
ActionServlet using introspection. And the Bean is then used by the Action (handler)
to modify/update the business
layer or model data. Then the actionForward is used to indicate which JSP the Servlet
should forward/dispatch to. The page (which could be a different JSP page or the same
used for the request) then searches for the ActionForm (bean) and creates one if it
does not exist in the request scope.
So (finally) here is the issue:
The controller and handler uses a "dumb" bean to modify the model (MVC). Cool!
But to gather information for use on a JSP, the bean must know how to gather that data
from
the business layer (model). BAD!!
The handler should configure the bean BEFORE dispatching to the JSP. This way, the
bean remains
"dumb" and the handler centralizes all knowledge of the business layer.
Struts seems to use 2 different patterns/approaches: the incoming processing is very
different than the processing used during display of the JSP.
Is my understanding correct?
ThomasB
Calmwater Software
ThomasB@Calmwaters
-----Original Message-----
From: Andreas Amundin [mailto:[EMAIL PROTECTED]]
Sent: Thursday, July 26, 2001 3:22 PM
To: '[EMAIL PROTECTED]'
Subject: RE: Creation of form bean
It is created by struts if it does not already exist. This is why the form
beans has to have a default constructor.
If one exists it will be used to populate the form with default values.
Rgs,
Andreas
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, July 26, 2001 1:18 PM
> To: [EMAIL PROTECTED]
> Subject: Creation of form bean
>
>
>
>
> Hi. Just a quick question - if I link directly to a jsp
> which contains an
> html:form tag with a formbean specified which I use on
> submit, is the formbean
> created by Struts?
>
> Or do I need to go through an empty action just to create it?
>
> thanks,
>
> Dave
>
>
>