cancel postback on onClientClicking

[Jagat]

I'm checking if the internet is available or not by pinging my server. This method is called in onClientClicking event of the button.

If not connected to the internet I want to prevent the postback.
It displays 'Not connected to internet' message but after the user clicks 'OK' , it does a postback.

function checkinternetOnButtonClick(button, args) {
                $.ajax({
                    url: 'http://www.MyDomainName.com',
                    success: function() {


                    },
                    error: function() {
                    alert('No internet connection available on button click!');
                    args.set_cancel(true);
                        return false;
                    }
                });
            }

<telerik:RadButton ID="btnBulkUpdate" runat="server" Text="Bulk Update" Width="150px"
                               Font-Size="Medium" OnClientClicking = "checkinternetOnButtonClick"   />

[Danail Vasilev]

Hello Jagat,

The OnClientClicking event executes too quickly, so that the set_cancel method in the error handler of the ajax request could not be executed.

What I can suggest you in that case is to simply cancel the postback of the RadButton at the beginning of the checkinternetOnButtonClick JavaScript function. Then you can trigger a button click on the success handler of the ajax request in order to make the postback. For example:

<script type="text/javascript">
    function checkinternetOnButtonClick(button, args) {
        args.set_cancel(true);
        $telerik.$.ajax({
            url: 'http://www.MyDomainName.com',
            success: function () {
                button.click();
            },
            error: function () {
                alert('No internet connection available on button click!');
            }
        });
    }
</script>

You can also find a similar scenario with the RadConfirm button located in Button - Confirm Postback online demo.

Kind regards,
Danail Vasilev
the Telerik team

[Jagat]

Thanks Danail,

I'm yet to try your suggestion.

I also need to check for internet connection when pageNumber on the RadGrid's pager  is clicked. How to I call checkinternetOnButtonClick function?

Thanks for your help!!

[Danail Vasilev]

Hi Jagat,

You can use the client-side event handlers OnPageIndexChanging or OnPageSizeChanging of the DataPager object, and there you can call the desired JavaScript function.

Greetings,
Danail Vasilev
the Telerik team