Elegant way to make CustomValidator work with ValidationSummary messagebox

Question

I have run into this problem before but never quite solved it. I have a form with several validators and also a CustomValidator.

<asp:Label ID="lblMemberNum" runat="server" Text="Membership #:" CssClass="LabelMedium"  ></asp:Label>
<asp:TextBox ID="txtMemberNum" runat="server" CssClass="TextBox" ></asp:TextBox>
<asp:RequiredFieldValidator ID="rfvMemberNum" SetFocusOnError="True" runat="server"
    ControlToValidate="txtMemberNum" ErrorMessage="[ Membership # ] is required"
    CssClass="ValidationMessage" Display="Dynamic" >*</asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="revMemberNum"  Display="Dynamic" runat="server" 
    ControlToValidate="txtMemberNum" CssClass="ValidationMessage" 
    ErrorMessage="[ Membership # ] can only contain letters" 
    ValidationExpression="^([a-zA-Z\d]+)$" >*</asp:RegularExpressionValidator>
<asp:CustomValidator ID="cvMemberNum" runat="server" 
    CssClass="ValidationMessage" Display="Dynamic"
    ControlToValidate="txtMemberNum" ValidateEmptyText="false"
    OnServerValidate="cvMemberNum_Validate" 
    ErrorMessage="This membership number is already registered">*</asp:CustomValidator>

<asp:ValidationSummary ID="ValidationSummary1" runat="server" 
    CssClass="ValidationMessage" 
    ShowMessageBox="True" ShowSummary="False" />

and on the server side:

protected void cvMemberNum_Validate(object source, ServerValidateEventArgs args)
{
    try
    {
        args.IsValid  = (!CampaignRegistration.IsMemberRegistered(args.Value));
    }
    catch
    {
        args.IsValid = false;
    }
}

My problem is: The ValidationSummary never shows the message from CustomValidator. This question has been asked in several places, but I havent seen a satisfactory answer.

Answer 1

Try using a ValidationGroup property across all your validators and the ValidationSummary.

EDIT: Another possibility could be the Server Validation Code

args.IsValid = (!CampaignRegistration.IsMemberRegistered(args.Value));

if CampaignRegistration.IsMemberRegistered(args.Value) is returning false, "!" is making it true and therefore making it valid. I think you should get rid of the "!" as follows:

args.IsValid = CampaignRegistration.IsMemberRegistered(args.Value);

UPDATE: In order for the ValidationSummary to display your custom validator message in a messagebox, you need to have ClientValidationFunction Code. If you need to display just the summary without a popup, this is not needed.

<asp:CustomValidator ID="cvMemberNum" runat="server" 
    CssClass="ValidationMessage" Display="Dynamic"
    ControlToValidate="txtMemberNum" ValidateEmptyText="false"
    OnServerValidate="cvMemberNum_Validate"
    ClientValidationFunction = "ClientValidate"  
    ErrorMessage="This membership number is already registered">*</asp:CustomValidator>
   //JavaScript Code.
   function ClientValidate(source, args)
   {         
      args.IsValid = false; //you need to add validation logic here
   }

MORE: If you don't want to do ClientSide Validation, try this trick to show the alert. Make this change to your CustomValidator ServerValidate method:

protected void cvMemberNum_Validate(object source, ServerValidateEventArgs args)
{
    bool isValid = true;
    try
    {
        isValid  = (!CampaignRegistration.IsMemberRegistered(args.Value));
    }
    catch
    {
        isValid = false;
    }
    args.IsValid = isValid;

    if(!isValid)
    {
       if(!Page.IsClientScriptBlockRegistered("CustomValidation")) 
         Page.RegisterClientScriptBlock("CustomValidation", "<script>alert('This membership number is already registered');</script>"); 

    }

}