Block Slider Auto Postback

[Yuri Kovalenko]

I have slider with AutoPostBack property set to "true". How can I block auto postback when changing value of a slider with the client side API? E. g. I don't need postback to fire when running this code:
$find('slider_name').set_value(0);
At the same time I need postback to fire when I change value of a slider by Drag Handle.

[Tsvetie]

Hello Yuri,
You cannot block the postback using the client-side API of the RadSlider. You can only cancel the ValueChange operation using the OnClientBeforeValueChange handler. Basically, in this case, you can think of the RadSlider as of a simple ASP Button. You can block the postback of the slider the same way you can block the postback of a Button when a certain condition is met.

For example:

<script type="text/javascript">
var toPostBack = true;
function OnClientValueChange(sender, args)
{
    if(toPostBack)
    {
        __doPostBack('<%= RadSlider1.ClientID %>');
    }
    else
    {
        toPostBack = true;
    }
}

function ChangeValueWithCode()
{
    var slider = $find('<%= RadSlider1.ClientID %>');
    toPostBack = false;
    slider.set_value(5);
}
</script>

<asp:Label ID="slValue" runat="server"></asp:Label>

<telerik:RadSlider ID="RadSlider1" runat="server"
    AutoPostBack="false"
    OnClientValueChange="OnClientValueChange"
    OnValueChanged="RadSlider1_ValueChanged"></telerik:RadSlider>

<button onclick="ChangeValueWithCode(); return false;">No PostBack</button>

protected void RadSlider1_ValueChanged(object sender, EventArgs e)
{
    slValue.Text = RadSlider1.Value.ToString();
}

Best wishes,
Tsvetie
the Telerik team

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