Where to put code to populate SELECT / OPTION lists?

[Martijn Spronk <sp...@columbusgroup.com>]

The part of my app I'm working on is a simple form submit, take the
struts-example/subscription for example.

My form is accessed by an editRequestTime.do?action=Create call in the
browser.
In the form I use the <html:select> and <html:option> tags to display
a selection box that is part of the form.

My problem is, what is the best place to create the ArrayList containing the
elements
for the option tag?

In the struts example it is hardcoded at the start of the JSP, with a
disclaimer that
it would normally be populated by the database (and I assume not in the
JSP).

So I figured I'll put it in my editRequestTimeAction code. Pass it on to the
JSP using
a request.setAttribute(). This works fine is the form is accessed through
the editRequestTime
call. 
However, the form submits to a new action, saveRequest.do. Which means that
if there is 
an error in the form, saveRequestAction will be executed, after which it
will forward to the form 
again. The form however is not aware of the ArrayList since it's not created
in the saveRequestAction
but only in the editRequestTimeAction.

It doesn't seem to make sense to have to create the ArrayList in both the
editRequestTimeAction
AND in the saveRequestTimeAction. Should I put the creation code (or at
least a handle to it)
in the JSP?? That doesn't seem to help the seperation?

Martijn.

Re: Where to put code to populate SELECT / OPTION lists?

[Scott Walter <tx...@yahoo.com>]

I have created a servlet where I do not code the
doGet() or doPost(), only the init() method.  This
allows me to get around the fact that the 2.2 servlet
api doesn't have a server startup event.

Then within the init() method I setup my arraylist of
values where each object in the arraylist is of type
LabelValueBean (which I got from the Struts Example).

I then store the arraylist as an application
attribute.  This way I can have dropdowns that
populated once and re-used across my entire app. 
Below is a sample servlet using this technique:

package sitemanager.shr.app;

import javax.servlet.http.*;
import javax.servlet.*;
import sitemanager.daemon.*;
import java.util.ArrayList;
import sitemanager.util.LabelValueBean;

/**
 *  Description of the Class
 *
 *@author     Scott F. Walter
 *@created    February 17, 2001
 */
public class InitApp extends HttpServlet {
	public void init(ServletConfig config) throws
ServletException {
		System.out.println("Loading dropdowns...");
		loadDropdowns(config);		
	}
	
	public void loadDropdowns(ServletConfig config) {
		ServletContext context = config.getServletContext();
		
		ArrayList list = new java.util.ArrayList();
		list.add(new LabelValueBean("What is your street
address?","" + 1));
		list.add(new LabelValueBean("Where were your
born?","" + 2));
		list.add(new LabelValueBean("What is your mother's
maiden name?","" + 3));
		list.add(new LabelValueBean("What is your favorite
car?","" + 4));
		
		context.setAttribute("dd_rememberpassword",list);		
	}
}
--- Martijn Spronk <sp...@columbusgroup.com> wrote:
> The part of my app I'm working on is a simple form
> submit, take the
> struts-example/subscription for example.
> 
> My form is accessed by an
> editRequestTime.do?action=Create call in the
> browser.
> In the form I use the <html:select> and
> <html:option> tags to display
> a selection box that is part of the form.
> 
> My problem is, what is the best place to create the
> ArrayList containing the
> elements
> for the option tag?
> 
> In the struts example it is hardcoded at the start
> of the JSP, with a
> disclaimer that
> it would normally be populated by the database (and
> I assume not in the
> JSP).
> 
> So I figured I'll put it in my editRequestTimeAction
> code. Pass it on to the
> JSP using
> a request.setAttribute(). This works fine is the
> form is accessed through
> the editRequestTime
> call. 
> However, the form submits to a new action,
> saveRequest.do. Which means that
> if there is 
> an error in the form, saveRequestAction will be
> executed, after which it
> will forward to the form 
> again. The form however is not aware of the
> ArrayList since it's not created
> in the saveRequestAction
> but only in the editRequestTimeAction.
> 
> It doesn't seem to make sense to have to create the
> ArrayList in both the
> editRequestTimeAction
> AND in the saveRequestTimeAction. Should I put the
> creation code (or at
> least a handle to it)
> in the JSP?? That doesn't seem to help the
> seperation?
> 
> Martijn.


=====
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Scott

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