JSF : How to populate textbox from Dropdown selection

[4fingers]

Hi, I hope someone can please help me with this
I select a value from a Dropdown, then click on an Edit button to edit the values for the selected Item. I want my page to now display the selected values in various text boxes below the Dropdown. When I check the values in the backing bean (prerender), I can see the new values which I want and even set the fields to, but when the page is displayed, I get blanks in those fields.

I have read that JSF will do a page validation and if it detects no changes it will display the same values again?

How do I get around this problem - I have done a lot of searching and simply cannot find a solution ?

Any help will be greatly appreciated.

[4fingers]

Hi

After bashing my head for a couple of days, I finally found the answer to my question. I will describe my fix below for the benefit of others just in case someone has a similar problem :
I left out a crucial piece of information in my original question
I did not mention that I was making use of Virtual Forms, which was in fact causing the problem in my code.

I added the following code in my button's Change_action() event :
form1.discardSubmittedValues("ItemDelete");
form1.discardSubmittedValues("ItemOk");
form1.discardSubmittedValues("ItemPreview");

This solved my problem of the latest value being displayed when selected
from the list and clicking the "Update" button.

Hope this helps someone else !

[ceyezumma]

Impressive
good job.
I have been trying to work with the jsf2.0 netbeans 6.8
Is this what you are working with.

I can't get the items loaded to the dropdown list. It would be great to see your code. if possible.

I'm trying to understand the JSF
Thanks
-ceyesumma

[4fingers]

Hi ceyesumma
I am currently using Netbeans 6.7.1 and Faces 1.2

In my case I am populating an Option[] in my Sessionbean.
You then bind your Dropdown to this array (right-click on Dropdown and click on bind to data. Select the listItems Option array).

I populate the array by calling it from the formsBean at the point
that I need it. In my web app, I have an Items tab and when I select it,
I call getSessionBean1().loadItems();

In the SessionBean, I have the following code :
Add :
private Option[] listItems; //Use this array to populate the list
private List<ItemsDTO> myItems; //Use this array to retrieve data
private ItemsDTO[] itemsArray; //Use array to hold Item details

Generate the relavant Getters and Setters for listItems:
public Option[] getListItems() {
return listItems;
}

public void setListItems(Option[] listItems) {
this.listItems = listItems;
}


Create a load method which will populate the array
public void loadItems(){
int listcount = 0;

// Check for items in array
if (getItemsArray() != null){
listcount = itemsArray.length;
}

// Clear array
for (int i=0; i<listcount; i++){
itemsArray[i] = null;
}


List loadList = new ArrayList();

// Create a new Data Access Object - connect to Oracle db
ORACLE_DAO myDAO = new ORACLE_DAO();

//Create a new Arraylist Collection and populate from db call
myItems = new ArrayList<ItemsDTO>();
myItems = myDAO.getItems(getSelectedInitiative());

//Process records retrieved from database
if (!myItems.isEmpty()){
itemsArray = new ItemsDTO[myItems.size()];

int i = 0;
for(ItemsDTO item : myItems){
itemsArray[i] = item;
loadList.add(item.getItemName());

//Pass the index and display value to method
addOption(item.getItemId(), item.getItemName());

i++;
}
}else{
//Create empty array
itemsArray = new ItemsDTO[10];
itemsCounter = 10;
}

if (itemsArray != null){
itemsCounter = itemsArray.length;
}

}

//Method to populate Option array with new values
public void addOption(int ii, String s) {
// Add a new item to the list by creating an
// updated array that contains the new item
Option opt = new Option(ii,s);

//Create a temp array to hold existing values
Option[] current;

//Populate temp array
current = getListItems();

int size = 0;

if (current == null){
size = 1;
}else{
size = current.length + 1;
}

// Create a new Option array with the new size
Option[] newOpts = new Option[size];

if (size > 1){
// add the current items to the new array
for (int i = 0; i < size - 1; i++){
newOpts[i] = current[i];
}
}
newOpts[size-1] = opt;

// Add the new Option to the list in question
setListItems(newOpts);

}


I hope I am not confusing you with my code

Cheers

[ceyezumma]

Thanks for your code.
I am now working with netbeans 6.7 again I think 6.8 should be running in November.

I worked with actionscript for the last 6months and I trying to switch gears back into java and good examples are hard to come by.
Are you aware of a good source of examples? The netbean page isn't really working for me at the moment.
Thanks again
-ceyesumma

[4fingers]

Hi ceyezumma
I make use of many of the Netbeans tutorials - http://www.netbeans.org/kb/index.html which is a great source of information. Then "University of Google" is your best friend

Some sites that I often look at :
www.javapassion.com - Training
http://java.sun.com/docs/books/tutorial/
http://java.dzone.com/
www.javaranch.com
www.nabble.com/
http://blogs.sun.com/
http://blogs.sun.com/divas/


There are numerous other good java sites, really depends on what you are looking for, and there Google is your best friend.

Good luck and happy hunting

[ceyezumma]

hey thanks I really need somathose.
these should help me while working on my associates in googleology

[jyeary]

I have an example on my blog on how to do this sort of binding.

http://javaevangelist.blogspot.com/2009/07/woodstock-dropdown-list-binding.html


On Thu, Aug 27, 2009 at 12:19 PM, 4fingers <address-removed ([email]address-removed[/email])> wrote: