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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.

note

The OnError event is supported by RadNumericTextBox , RadMaskedTextBox , and RadDateInput .

On RadNumericTextBox and RadDateInput, the following two parameters are passed to the event handler:

  • sender is the input control.

  • eventArgs has the following methods:

    • set_cancel() lets you tell the input control to cancel the event that caused the error.

    • get_inputText() returns the value that the user tried to assign to the input control, except in the case when RadNumericTextBox detects an invalid character, in which case it returns the current value of the numeric text box.

    • get_reason() returns a value indicating the type of error that was detected.The possible values are:

      1. Parsing error.

      2. Out of range.

note

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).

On RadMaskedTextBox, the following two parameters are passed to the event handler:

  • sender is the masked text box.

  • eventArgs has the following methods:

    • set_cancel() lets you tell the masked text box to cancel the event that caused the error.

    • get_newValue() returns the invalid value that the user tried to assign to a mask part.

    • get_oldValue()returns the value that was assigned to the mask part before the error.

    • get_currentPart() returns the client-side object of the mask part that detected the error.

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