RE: [flexcoders] FB2B3 programmatically select an item in a ComboBox

Gordon Smith Tue, 16 May 2006 14:00:09 -0700

The whole chain of what?

Storing the dataProvider, the loop limit, and the data you're looking for in local vars WOULD be more efficient because they remain the same throughout the loop and it is inefficient to evaluate them over and over. But the item changes with each iteration so storing it in a local var before accessing its data property is just an extra step.

var dp:Object = cboCountry.dataProvider;
var n:int = dp.length;
var country:String = event.result.COUNTRY;

for (var i:int = 0; i < n ; i++)
{
    if (dp.getItemAt(i).data == country)
    {
        cboCountry.selectedIndex = i;
        break;
    }
}

- Gordon

From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of jeremy lu
Sent: Tuesday, May 16, 2006 3:00 AM
To: [email protected]
Subject: Re: [flexcoders] FB2B3 programmatically select an item in a ComboBox

hi Gordon,

that's interesting, please bring it back here if you do get time to check it, thanks :-)

btw, my rationale behind this is: player don't have to evaluate the whole chain during the loop by assigning it to a variable, but I might just be wrong.

On 5/16/06, Gordon Smith <[EMAIL PROTECTED]> wrote:

I'd expect that introducing an unnecessary local var would make it slightly less efficient, but I haven't looked at the bytecode for the two cases.

- Gordon

From: [email protected] [mailto: [email protected]] On Behalf Of jeremy lu
Sent: Monday, May 15, 2006 7:01 PM
To: [email protected]
Subject: Re: [flexcoders] FB2B3 programmatically select an item in a ComboBox

glad that helped.

adding var itm:* = cboCountry.dataProvider.getItemAt(i) might be a little bit efficient.

On 5/16/06, Steve Gustafson <[EMAIL PROTECTED]> wrote:

That solved it!
The key is using the dataProvider.length instead of the ComboBox .length

I shortened the code block a little to:

for(var i:Number = 0; i < cboCountry.dataProvider.length ; i++)
{

    if (cboCountry.dataProvider.getItemAt(i).data == event.result.COUNTRY)
    {
        cboCountry.selectedIndex = i;
        break;
    }
}

Thanks for the help!

Steve

On 5/15/06, jeremy lu <[EMAIL PROTECTED]> wrote:

well, I believe all the getItemAt() methods are removed from List-base components like Combobox, List, DataGrid in F2B3.

to do the loop correctly, try this:

for(var i:Number = 0; i < cboCountry.dataProvider.length; i++)
{
     var itm:* = cboCountry.dataProvider.getItemAt(i);

      if( itm.data == event.result.COUNTRY )
      {
        cboCountry.selectedIndex = i;
        break;

}
}

On 5/16/06, Simeon Bateman <[EMAIL PROTECTED] > wrote:

Well I dont know exactly what is wrong, but using flex builder it would be pretty easy to set a break point on the "if" line of code and then step through the loop to ensure that those to variables are what you think they should be.

I use a mac and so my solution is to just use an alert to pop up the 2 items each loop so I can compare them.

Give it a look, you might find that the two don't actually match up.

The other thing, is that if you are doing this on a tabnavigator or accordian and the page you are setting has not yet been drawn then the items wont get selected even if they match. If this is the case you might have to look into the creationPolicy for the parent, to ensure the children are all created before you try to set properties on them.

Hope that helps.

simeon

On 5/15/06, Steve Gustafson <[EMAIL PROTECTED]> wrote:

Greetings and thanks in advance for your help!

I have a ComboBox that displays a countries.
The label is a country Name
The data is a country code

I then retrieve a users record via AMF. Standard stuff with First Name, Last Name etc.

I am populating various fields with the retrieved data, which is working fine.

Where I am stuck is on the country ComboBox. I want to select the appropriate country for the user.

I expected something like this to work:

for(var i:Number = 0; i < cboCountry.length; i++)
{
      if(cboCountry.getItemAt(i).data == event.result.COUNTRY)
      {
        cboCountry.selectedIndex = i;
        break;
      }
}

I have yet to figure out how to loop through the ComboBox to match the users country. Or if I even need to run a loop in FB2B3.

This has got to be a very common task, yet I am not finding any decent info on an approach.

Any help is greatly appreciated.

Steve

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