This is a migrated thread and some comments may be shown as answers.

Limit number of items added to RadListBox2

14 Answers 420 Views

ListBox

This is a migrated thread and some comments may be shown as answers.

14 Answers, 1 is accepted

answered on 19 Mar 2010, 05:03 PM

Thanks for your suggestion. I am getting closer. Still have a small issue to figure out.

When using OnClientTransferring, when I check the count of RadListBox2 it gives the count of items before the transfer.

I am allowing SelectionMode="multiple". So, if there are already 7 items in RadListBox2 and they select 5 items from RadListBox1, the code allows the transfer as the count is < 10. But, we end up with 12 items in RadListBox2.

I have tried to use get_selected to find the number of items being transfered. But, it seems that once the "transfering" starts, they are no longer selected. So, I have been unable to make that work.

I am planning on adding some code for the OnClientTransfered as that gives me an accurate count of the new number of items after the transfer. But, at this point it is not possible to use the set_cancel(true). So, I will just have to write code that deletes the extra times.

If anyone has a better way to detect the number of items being transfered + the number of items currently in RadListBox2 to prevent more than 10 items total in RadListBox2, so that I can use the set_cancel(true), that would be a much better solution and I appreciate any assistance.

Thanks

Mike

answered on 23 Mar 2010, 04:10 PM

Hi Mike T,

In the clientTransferring event you can use the following code to find out how many items are being transferred:

<script type="text/javascript">

function clientTransferring(sender, args) {

var count = args.get_items().length;

}

</script>

<telerik:RadListBox runat="server" ID="RadListBox1" AllowTransfer="True"

TransferToID="RadListBox2" OnClientTransferring="clientTransferring" SelectionMode="Multiple">

Best wishes,
Genady Sergeev
the Telerik team

Do you want to have your say when we set our development plans? Do you want to know when a feature you care about is added or when a bug fixed? Explore the Telerik Public Issue Tracking system and vote to affect the priority of the items.

answered on 23 Mar 2010, 07:29 PM

Closer. This now works perfectly as long as you are transferring items from RadListBox1 to RadListBox2.

Is there any way to determine which direction items are being transferred?

IE, the goal here is to limit the number of items in RadListBox2 to no more than 10 items.

When transferring from box1 to box2, I can now get the number of items already in box2 + the items being transfered and this code works great.

However, it seems to trigger the same code block when transferring from box2 to box1. Example, if there are 9 items in box2. The user wants to remove some of those to make room for something else. So, they select 3 items and move them back to box1. The transfer triggers the code which gives items currently in box2 (9) + items being transfered (3) = 12 which is more than the 10 so it kills the transfer.

The code should only be triggered if the transfer is from box1 to box2. Is there anyway to determine this?

Thanks

Mike T

answered on 26 Mar 2010, 11:52 AM

Hi Mike T,

You can use the following code to determine which is the destination listbox:

<script type="text/javascript">

function clientTransferring(sender, args) {

var destinationListBox = args.get_destinationListBox();

}

</script>

<telerik:RadListBox runat="server" ID="RadListBox1" AllowTransfer="True"

TransferToID="RadListBox2" OnClientTransferring="clientTransferring" SelectionMode="Multiple">

Greetings,
Genady Sergeev
the Telerik team

answered on 26 Mar 2010, 06:46 PM

Thanks. That was the last piece of the puzzle.

If anyone else needs to do the same, the finished code is:

function clientTransferring(sender, args) {

var destinationListBox = args.get_destinationListBox();

if (destinationListBox.get_id()=='RadListBox2') {

var lb2 = $find("<%= RadListBox2.ClientID %>");

var intTransCount = args.get_items().length;

var intDestCount = lb2.get_items().get_count();

var intTotalCount = intTransCount + intDestCount;

if (intTotalCount > 10) {

args.set_cancel(true);

alert('You may only select up to 10 at a time.');

}

<telerik:RadListBox ID="RadListBox1" runat="server" AllowTransfer="True" TransferToID="RadListBox2"

AllowTransferOnDoubleClick="True" EnableDragAndDrop="True" SelectionMode="Multiple" OnClientTransferring="clientTransferring"></telerik:RadListBox>

<telerik:RadListBox ID="RadListBox2" runat="server" ></telerik:RadListBox>

Thanks for all of your help

Mike T

answered on 27 Sep 2010, 09:54 AM

testtransfer.zip

Hello Steve,

You can find sample project demonstrating how to do that as an attachment.

Kind regards,
Genady Sergeev
the Telerik team

answered on 12 Sep 2016, 12:32 PM

I was able to get this working by putting the following code at the bottom of my content page. I display the message in a RadWindow by putting a RadWindowManager with the ID of "rwmMessage" at the top of the screen. Because I am using a master page I had to fully qualify the name of the target listbox as "ctl00_MainContent_RadListBoxDestination" and not just it's ID of "RadListBoxDestination". Is there a better way to do this?

function onClientTransferring(sender, args) {

if (args.get_destinationListBox().get_id() == "ctl00_MainContent_RadListBoxDestination")

handleSourceToDestinationTransfer(args);

}

function handleSourceToDestinationTransfer(args) {

var maxNumberOfItems = 10;

var dest = args.get_destinationListBox();

var totalCount = dest.get_items().get_count();

var itemsToTransferCount = args.get_items().length;

if (totalCount == maxNumberOfItems) {

var oWnd = window.radalert("You may only select a maximum of 10 ports.", 330, 180, "Error");

args.set_cancel(true);

} else if (totalCount + itemsToTransferCount > maxNumberOfItems) {

while (totalCount + itemsToTransferCount > maxNumberOfItems) {

itemsToTransferCount--;

args.get_items().pop();

}