ASP.NET Custom Validator Client side & Server Side validation not firing
Solution 1
Your CustomValidator
will only fire when the TextBox
isn't empty.
If you need to ensure that it's not empty then you'll need a RequiredFieldValidator
too.
EDIT:
If your CustomValidator
specifies the ControlToValidate
attribute (and your original example does) then your validation functions will only be called when the control isn't empty.
If you don't specify ControlToValidate
then your validation functions will be called every time.
This opens up a second possible solution to the problem. Rather than using a separate RequiredFieldValidator
, you could omit the ControlToValidate
attribute from the CustomValidator
and setup your validation functions to do something like this:
Client Side code (Javascript):
function TextBoxDCountyClient(sender, args) {
var v = document.getElementById('<%=TextBoxDTownCity.ClientID%>').value;
if (v == '') {
args.IsValid = false; // field is empty
}
else {
// do your other validation tests here...
}
}
Server side code (C#):
protected void TextBoxDTownCity_Validate(
object source, ServerValidateEventArgs args)
{
string v = TextBoxDTownCity.Text;
if (v == string.Empty)
{
args.IsValid = false; // field is empty
}
else
{
// do your other validation tests here...
}
}
Solution 2
Use this:
<asp:CustomValidator runat="server" id="vld" ValidateEmptyText="true"/>
To validate an empty field.
You don't need to add 2 validators !
Solution 3
Client-side validation was not being executed at all on my web form and I had no idea why. It turns out the problem was the name of the javascript function was the same as the server control ID.
So you can't do this...
<script>
function vld(sender, args) { args.IsValid = true; }
</script>
<asp:CustomValidator runat="server" id="vld" ClientValidationFunction="vld" />
But this works:
<script>
function validate_vld(sender, args) { args.IsValid = true; }
</script>
<asp:CustomValidator runat="server" id="vld" ClientValidationFunction="validate_vld" />
I'm guessing it conflicts with internal .NET Javascript?
Solution 4
Did you verify that the control causing the post back has CausesValidation set to tru and that it does not have a validation group assigned to it?
I'm not sure what else might cause this behavior.
REA_ANDREW
Typing keys in the correct order (generally) since 2004. Occasionally the key strokes produce something useful. Other times it is backspace FTW, then I realise I am in command mode. :xa @REA_ANDREWlinkedin
Updated on July 05, 2022Comments
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REA_ANDREW almost 2 years
This has not happened to me before, but for some reason both the client and server side validation events are not being triggered:
<asp:TextBox ID="TextBoxDTownCity" runat="server" CssClass="contactfield" /> <asp:CustomValidator ID="CustomValidator2" runat="server" EnableClientScript="true" ErrorMessage="Delivery Town or City required" ClientValidationFunction="TextBoxDTownCityClient" ControlToValidate="TextBoxDTownCity" OnServerValidate="TextBoxDTownCity_Validate" Display="Dynamic" > </asp:CustomValidator>
Server-side validation event:
protected void TextBoxDTownCity_Validate(object source, ServerValidateEventArgs args) { args.IsValid = false; }
Client-side validation event:
function TextBoxDCountyClient(sender, args) { args.IsValid = false; alert("test"); }
I thought at the least the Server Side validation would fire but no. this has never happened to me before. This has really got me stumped.
I looked at the output and ASP.NET is recognizing the client side function:
ASP.NET JavaScript output:
var ctl00_ctl00_content_content_CustomValidator2 = document.all ? document.all["ctl00_ctl00_content_content_CustomValidator2"] : document.getElementById("ctl00_ctl00_content_content_CustomValidator2"); ctl00_ctl00_content_content_CustomValidator2.controltovalidate = "ctl00_ctl00_content_content_TextBoxDTownCity"; ctl00_ctl00_content_content_CustomValidator2.errormessage = "Delivery Town or City required"; ctl00_ctl00_content_content_CustomValidator2.display = "Dynamic"; ctl00_ctl00_content_content_CustomValidator2.evaluationfunction = "CustomValidatorEvaluateIsValid"; ctl00_ctl00_content_content_CustomValidator2.clientvalidationfunction = "TextBoxDTownCityClient";
Rendered custom validator:
<span id="ctl00_ctl00_content_content_CustomValidator2" style="color:Red;display:none;">Delivery Town or City required</span>
Can any one shed some light as to why both client and server side validation would not be firing.
Edit: Typo I pasted in the wrong function, problem still the same
Just another update to the last comment: where by the TextBox cannot be empty. I tested this out and it is not true. On a blank page the CustomValidator fired my client side validation function fine without a value:
<asp:TextBox ID="TextBox1" runat="server" /> <asp:CustomValidator ID="CustomValidator1" runat="server" ErrorMessage="CustomValidator" ClientValidationFunction="TextBoxDAddress1Client"></asp:CustomValidator> <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
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REA_ANDREW about 15 yearsI use an ImageButton for the Submit, and I have not stated any validation group.
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David Waters about 15 yearstoo quick for me, I was typing same answer :) +1
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REA_ANDREW about 15 years"Your CustomValidator will only fire when the TextBox isn't empty" I tested this on a clean page and it is not true. The client validation function fires even when the textbox is empty
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REA_ANDREW about 15 yearsMy bad. I see what i need to do. If I omit the ControlToValidate property then I succeed in what I want to do, and the client side function fires when I need.
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Mike Cole about 15 yearsThis is a cool fix and worked for me. However, I use the ValidatorCalloutExtender from the Ajax Control Toolkit and it requires the ControlToValidate property to be set. It's always something... :-(
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Tys almost 12 yearsDont forget to specify your javascript script tag correctly, otherwise the validation method is not triggered. (Only if you use an ugly javascript block in your ASPX file.) <script language="javascript" type="text/javascript">
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Mehmood almost 8 yearsThe solution i was searching for. Thanks.
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IrishChieftain over 6 yearsYou could also use the CustomValidator.ValidateEmptyText Property? msdn.microsoft.com/en-us/library/…