OnError

The OnError client-side event handler is called when the input control detects that the user has tried to enter an invalid value. The input control may detect the error when the user presses a key to enter an invalid character, or after the input control loses focus and parses the value the user entered.

When RadDateInput cannot parse the value that the user entered, it raises two OnError events -- the first with the reason set to 1 (Parsing error) and the second with the reason set to 2 (Out of range).

The following example uses the OnError event to raise an alert when an error is detected:

<telerik:RadMaskedTextBox RenderMode="Lightweight" ID="RadMaskedTextBox1" runat="server" Mask="(###) ###-#####">
    <ClientEvents OnError="HandleError" />
</telerik:RadMaskedTextBox>
<telerik:RadTextBox RenderMode="Lightweight" ID="RadTextBox1" runat="server">
    <ClientEvents OnError="HandleError" />
</telerik:RadTextBox>
<telerik:RadNumericTextBox RenderMode="Lightweight" ID="RadNumericTextBox1" runat="server" MaxValue="10" MinValue="0">
    <Clientevents onerror="HandleError" />
</telerik:RadNumericTextBox>

<script type="text/javascript">
    function HandleError(sender, eventArgs)
    {
        if (sender.get_id() == "<%= RadMaskedTextBox1.ClientID %>")
        {
            alert("Invalid value: " + eventArgs.get_newValue());
            var part = eventArgs.get_currentPart();
            if (part)
            {
                sender.set_cursorPosition(part.offset);
            }
        }
        else
        {
            switch (eventArgs.get_reason())
            {
                case 1: // Parsing error     
                    if (sender.get_id() == "<%= RadNumericTextBox1.ClientID %>")
                        alert("Invalid character!");
                    else
                        alert("Value could not be parsed: " + eventArgs.get_inputText());
                    break;
                case 2: // Out of range
                    alert("Value out of range: " + eventArgs.get_inputText());
                    break;
            }
        }
        eventArgs.set_cancel(true);
    }
</script>

See Also

• OnValueChanging