struts-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Schuster Joel M Contr ESC/NDC <Joel.Schus...@cisf.af.mil>
Subject RE: Correct Prepopulate Method
Date Fri, 11 Mar 2005 19:39:49 GMT
Ok, I understand. I'm just really trying to understand this.

http://resonus.net/wiki/uploads/strutsq.jpg

Here's a link to a little picture that I put together because that happens
to be how I think.

Please tell me what I'm missing in my understanding of what struts is all
about. 

1. Standard login process.
	a) request to website from browser, we redirect to the login.jsp via
an action or forward.
	b) Submit is clicked and system encapsulates the data from the
request into a form which is then given to the action.execute which
	c) then determines if the values are correct and forwards to the
right place depending.

2. Now, If I want to have the main menu simply go from one screen to another
then I have a link. But the second screen needs to be 'populated' (for lack
of a better word) with data. 

3. To do it the struts 'way' is to link to an action instead. This action
fills the framework provided form (because it is defined in the mapping) and
forwards to the edit screen.

4. The update action uses the same form which is now filled with changed
values from the jsp.

--- I keep getting the impression that I've missed something in my
understanding of how and more importantly why --- I want to understand, not
just do things blindly.

I understand that the ActionForm is intended to STORE and VALIDATE
USER-ENTERED data (off the struts page)... but then there seems to be a big
hole in the functionality of struts. How do you get to the point of having a
person select inventory and purchase it if you can't first display that
inventory?

- Joel


-----Original Message-----
From: Dakota Jack [mailto:dakota.jack@gmail.com] 
Sent: Friday, March 11, 2005 12:02 PM
To: Struts Users Mailing List
Subject: Re: Correct Prepopulate Method

I may be wrong, Joel, but I think Joe and Hubert are thinking of you
instantiating a form that is not listed in your action mapping.  You
can readily figure out why they think this way.  You can, as you seem
to want to, avoid this complication that actually sort of takes you
out of the reason for the Struts framework by having your ActionForm
encompass the data in both the "pre-Action" and "post-Action" JSP/HTML
forms.

Jack


On Fri, 11 Mar 2005 11:57:33 -0700, Schuster Joel M Contr ESC/NDC
<Joel.Schuster@cisf.af.mil> wrote:
> I've been looking into the RequestProcessor and RequestUtils classes and
it
> looks like as long as my action mapping specifies a name, even on a setup
> action goes through the same process... calling createActionForm().
> 
> Thus there is no reason to go through my own ModuleConfig again.
> 
> 
> -----Original Message-----
> From: Hubert Rabago [mailto:hrabago@gmail.com]
> Sent: Friday, March 11, 2005 10:13 AM
> To: Struts Users Mailing List
> Subject: Re: Correct Prepopulate Method
> 
> On Fri, 11 Mar 2005 09:50:59 -0700, Schuster Joel M Contr ESC/NDC
> <Joel.Schuster@cisf.af.mil> wrote:
> > I'm not sure I understand the need for the moduleConfig and such for
> > creating the DynaActionForm.
> 
> The FormBeanConfig object provides access to the createActionForm()
> method.  That's the object you actually need.  You can get to that
> through the ModuleConfig for the current module.
> 
> >
> > If we've specified the name="myForm" in the action config then shouldn't
> the
> > form coming into the execute be and empty version of my form? Thus
> allowing:
> >
> >      execute( ActionMapping mapping, ActionForm form ... {
> >             DynaActionForm myForm = (DynaActionForm) form;
> >      }
> >
> > (As a matter of fact I know this works :))
> >
> 
> This is true when you're in the action to which the form was
> submitted.  In the example I gave, this would be the /submitForm
> action.  In a setup action, this mapping may not be available or may
> be referring to a different form altogether.
> 
> > Also, using
> >
> > request.getSession().setAttribute("myForm", myForm);
> >
> > is exactly the issue. Although it then allows the follow up jsp to gain
> > access to the formbean during form(html) creation it doesn't determine
how
> > then to remove the form from the session except by explicit removal in
the
> > final update/submit action unless you config the submit as request scope
> > only. But that doesn't actually remove the formbean from the session
scope
> > that we added it into... it just copies it into the request scope too.
> >
> > --- so back to sqare one. :P
> 
> You can specify which scope you want the form bean to be in (read the
> bottom of my prev email).  Struts uses session scope by default, which
> is why that's what I mentioned first.  You can choose to use request
> scope.
> 
> hth,
> Hubert
> 
> >
> >
> > -----Original Message-----
> > From: Hubert Rabago [mailto:hrabago@gmail.com]
> > Sent: Friday, March 11, 2005 9:36 AM
> > To: Struts Users Mailing List
> > Subject: Re: Correct Prepopulate Method
> >
> > You would usually do prepopulation in a setup form.  Which scope you
> > place the form in depends on how you configure the action that the
> > form will be submitted to.  For example, if you have "/showPage.do"
> > and "/submitForm.do", where submitForm is configured as:
> >
> > <action path="/submitForm" name="myForm" ...>....</action>
> >
> > Then in the action for showPage, you'd:
> >
> >     ModuleConfig moduleConfig =
> > ModuleUtils.getInstance().getModuleConfig(request);
> >     FormBeanConfig formBeanConfig =
> > moduleConfig.findFormBeanConfig("myForm");
> >     DynaActionForm myForm = (DynaActionForm)
> > formBeanConfig.createActionForm(getServlet());
> >
> >     myForm.set("propName",propValue);
> >     request.getSession().setAttribute("myForm", myForm);
> >
> > If you want to use request scope, change /submitForm to:
> > <action path="/submitForm" name="myForm"
scope="request"...>....</action>
> >
> > then in showPage:
> >     request.setAttribute("myForm", myForm);
> >
> > Hubert
> >
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: user-unsubscribe@struts.apache.org
> For additional commands, e-mail: user-help@struts.apache.org
> 
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: user-unsubscribe@struts.apache.org
> For additional commands, e-mail: user-help@struts.apache.org
> 
> 


-- 
"You can lead a horse to water but you cannot make it float on its back."
~Dakota Jack~

---------------------------------------------------------------------
To unsubscribe, e-mail: user-unsubscribe@struts.apache.org
For additional commands, e-mail: user-help@struts.apache.org

---------------------------------------------------------------------
To unsubscribe, e-mail: user-unsubscribe@struts.apache.org
For additional commands, e-mail: user-help@struts.apache.org


Mime
View raw message