Using radconfirm() CallBackFunction to perform a postback

Environment

Product

Telerik WebForms ToolBar for ASP.NET AJAX

Description

Unlike the standard confim(), radconfirm() cannot block the execution of the thread (this is something that cannot be done with Javascript) and a CallBackFunction is needed.

The sample code snippet demonstrates a real-life scenario where when clicking one of the Toolbar's buttons we want to ask a confirmation from the user before performing the postback. RadWindowManager and RadToolbar are wrapped in RadAjaxPanel to avoid full page's postback.

Solution

The implementation of such scenario is relatively simple - when the user clicks on the button, we need to make a check what button is clicked and if it is the one which requires confirmation - cancel the postback and call radconfirm().

Once the user confirms the postback, in the radconfirm's CallBackFunction we will use __doPostBack() to send the information on the server:

    <%= RadToolbar1.ClientID %>.attachEvent("OnClientClick", "Toolbar_ClientClick");

    function Toolbar_ClientClick(sender, e) {
        if (sender.CommandName == "Delete") {
            radconfirm("Delete?", CallBackFn);
            return false;
        }
        else {
            return true;
        }
    }

    function CallBackFn(arg) {
        if (arg) {
            __doPostBack("<%= RadToolbar1.UniqueID %>", "onclick#Delete");
        }
    }

In the __doPostBack() we are provide the following arguments:

1. The UniqueID of the RadToolbar - this will allow us to reference the toolbar even if a MasterPage is used
2. The RadToolBar command that we want to be executed.

And in the codebehind:

protected void RadToolbar1_OnClick(object sender, Telerik.WebControls.RadToolbarClickEventArgs e)  
{  
    Message.Text = "You clicked " +  e.Button.CommandName + " " + DateTime.Now.ToString("hh:mm:ss");  
} 

DOWNLOAD the sample project: toolbar-using-radconfirm-callbackfunction-to-perform-a-postback.zip