Confirm Closing
It is a common scenario that a confirmation is required from the user just before a popup dialog is closed, e.g. to confirm discarding changes. To achieve this with the RadWindow the OnClientBeforeClose event must be used. Two simple examples follow below. They can be extended to only ask for confirmation depending on a flag that can be raised from inside the content page -just wrap the functionality in an IF block. How to access the main page from inside the content page is explained in this help article. It also shows how to get a reference to the RadWindow from inside the content page, so that a custom field in the RadWindow object can also be used instead of using a global variable. The event handler receives the RadWindow instance as the first parameter and JavaScript allows for dynamic creation of fields inside the object.
Using the Standard Confirm dialog
The simplest approach is to use the standard browser confirm() dialog. It blocks the execution thread and thus interrupts the entire page:
<telerik:RadWindow RenderMode="Lightweight" runat="server" ID="RadWindow1" OnClientBeforeClose="OnClientBeforeClose">
</telerik:RadWindow>
<asp:Button ID="Button1" Text="text" runat="server" />
<script type="text/javascript">
function OnClientBeforeClose(sender, args)
{
args.set_cancel(!confirm("Are you sure you want to close this window"));
}
</script>
Using the RadConfirm dialog
The RadConfirm dialog is a standard RadWindow and thus cannot block the thread execution like the browser confirm() can. This means that the logic must be extended to dynamically add/remove the OnClientBeforeClose handler. The RadConfirm also requires that there is a RadWindowManager on the same page and that the event is cancelled each time so that the RadWindow can be closed with code depending on the user input. The benefit from this approach is that it provided consistent look and styling.
<telerik:RadWindowManager RenderMode="Lightweight" runat="server" id="RadWindowManager1"></telerik:RadWindowManager>
<telerik:RadWindow RenderMode="Lightweight" runat="server" ID="RadWindow1" OnClientBeforeClose="OnClientBeforeClose">
</telerik:RadWindow>
<script type="text/javascript">
function OnClientBeforeClose(sender, args)
{
args.set_cancel(true);
function confirmCallback(arg)
{
if (arg)
{
sender.remove_beforeClose(OnClientBeforeClose);
sender.close();
sender.add_beforeClose(OnClientBeforeClose);
}
}
radconfirm("Are you sure you want to close this window?", confirmCallback);
}
</script>