strange "behavior" when using args.set_cancel(true)

[Eric]

I have been working with client script using RadButton, and noticed some odd behavior when calling args.set_cancel. During the OnClientClicking event, i check a condition, if true, button is allowed to postback, if false, set_cancel is set to true. I have two buttons using this event.

function OnClientClicking(sender, args) {
    if (somecondition == false) {
        args.set_cancel(true);
    }
}

Now, if I click Button1, and somecondition is false, then the postback will cancel. However, if I click Button2 next, when the OnClientClicking event is fired, somecondition is true, and set_cancel(true) is NOT called, but... the button does not post back. Now if I reload the page and click Button2 first, then it posts back, until i click Button1, then Button2 no longer posts back.

I tried explicitly calling args.set_cancel(false); 
but it still does not work right.

function OnClientClicking(sender, args) {
    if (somecondition == false) {
        args.set_cancel(true);
    } else {
        args.set_cancel(false);
    }
}

Any ideas what might be causing this weirdness?

[Shinu]

Hi Eric,

I have tried a similar scenario and its working fine at my end. Here is the sample code I tried.

ASPX:

<telerik:RadButton ID="RadButton1" runat="server" Text="Button 1" OnClientClicking="OnClientClicking"
    OnClick="RadButton1_Click">
</telerik:RadButton>
<telerik:RadButton ID="RadButton2" runat="server" Text="Button 2" OnClientClicking="OnClientClicking"
    OnClick="RadButton2_Click">
</telerik:RadButton>

JavaScript:

<script type="text/javascript">
    function OnClientClicking(sender, args) {
        if (sender._text == "Button 1") {
            args.set_cancel(true);
        }
    }
</script>

Thanks,
Shinu.

[Eric]

well, I tried your code and yes, it works as expected, however... i realized something. I forgot to mention that i was using SingleClick=true and one button had causes validation set to false.

<asp:TextBox ID="txtTest" runat="server" />
<asp:RequiredFieldValidator ID="rfvtxtTest" ErrorMessage="Test is required" ControlToValidate="txtTest"
    runat="server" />

<telerik:RadButton ID="RadButton1" runat="server" Text="Button 1" OnClientClicking="OnClientClicking"
    SingleClick="true" CausesValidation="true">
</telerik:RadButton>
<telerik:RadButton ID="RadButton2" runat="server" Text="Button 2" OnClientClicking="OnClientClicking"
    SingleClick="true" CausesValidation="false">
</telerik:RadButton>

the code above does exactly what I described. First button will have its set_cancel set to true, and button 2 will not trigger postback after button 1 is pressed.

So I narrowed down the issue to validation. I have a textbox with a required field validator. Button 1 trips validation, Button 2 is clicked... no post back. If Button 2 is pressed, it will post back until Button 1 trips the validator, then Button 2 will stop posting back.

Sorry, I should have mentioned the SingleClick and CausesValidation

EDIT: One more thing. I know you're probably wondering, why use set_cancel? Well, I'm working on a custom button for our developers, and i need to cancel the OnClientClick event to prevent other script from running. I can do a work around in the meantime, but I figured I would point out this oddness.

[Danail Vasilev]

Hi Eric,

I have successfully reproduce the unexpected behavior. This seems to be an issue with the control when a RadButton is clicked and the following conditions are met:

• Page validation is not passed
• RadButton's postback is cancelled in OnClientClicking event by setting args.set_cancel(true)

which leads to the prevention of the postback of the RadButtons.

I have logged the issue in our feedback portal here, so that you can monitor, comment and vote on it.

I have also updated your Telerik points for reporting this issue to us.

Regards,
Danail Vasilev
Telerik

[Keith]

I also need a button to conditionally postback. Getting this to work correctly will solve many problems for me.