Re: Data from .jsp page in JSF Application

From:
Arved Sandstrom <dcest61@hotmail.com>
Newsgroups:
comp.lang.java.programmer
Date:
Tue, 25 Aug 2009 18:39:41 GMT
Message-ID:
<NdWkm.40631$Db2.34539@edtnps83>
Mongoose wrote:

On Aug 24, 7:53 pm, Arved Sandstrom <dces...@hotmail.com> wrote:

[ SNIP ]

Just create your page as per normal, but for the select lists and menus,
input texts, radio buttons and checkboxes, all you need to specify is an
ID (obviously for the menus and listboxes you'll still need to supply
content in the usual way). Make the IDs nice and descriptive - they will
be your control map keys.

So no "binding" attributes, no "value" attributes.

In the action method, get the UIViewRoot from the FacesContext and
recursively walk the component tree. The getFamily() method on each
UIComponent will tell you whether or not it's a UIInput, or
UISelectMenu, and so forth. The getValue() method (you can ignore
getLocalValue() and getSubmittedValue()) will give you the actual value
you're looking for. Bear in mind it will be an array for the listboxes.
Also keep in mind converters if you've used any.

You can easily populate a HashMap or whatever with id-value pairs as you
walk the tree.

AHS- Hide quoted text -

- Show quoted text -


Hey Arved . . . thanks for that . . . exactly what I want to do . . .

However, I was wondering if you could sketch the loop out that walks
the component tree in a little more detail for me? I'm having trouble
finding the exact syntax of how to do that on the web . . . and I'm
still learning JSF so I'm not familiar with all the syntax and such
yet . . .

Thanks so much,

Andy


Here's one quick example:

package org.ahs.jsf.controls;

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.faces.component.UIComponent;
import javax.faces.component.UIInput;
import javax.faces.component.UIViewRoot;
import javax.faces.context.FacesContext;

public class ControlMapBean {

   public String save() {
     UIViewRoot viewRoot =
       FacesContext.getCurrentInstance().getViewRoot();
     Map<String, Object> controlMap =
       new HashMap<String, Object>();

     analyzeComponent(viewRoot, controlMap);

     // do stuff with loaded control map

     return null;
   }

   private void analyzeComponent(UIComponent uic,
       Map<String, Object> controlMap) {
     if (uic instanceof UIInput) {
       controlMap.put(uic.getId(),
         ((UIInput)uic).getValue());
     }

     if (uic.getChildCount() > 0) {
       List<UIComponent> children = uic.getChildren();
       for (UIComponent child : children) {
         analyzeComponent(child, controlMap);
       }
     }
   }
}

This is barebones. Once you have the control map it's up to you to
interpret the map values, but presumably that's where your logic comes
in, because at a minimum you need to know what the ID's correspond to.
In general they will be single values or arrays
(object.getClass().isArray() will help you here).

AHS

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