Using RequiredFieldValidator to check if at least one of the two textboxes has some text inside?

Question

I have two textboxes on my asp.net page and a submit button. How can I use a single or more RequiredFieldValidators to check if at least one of the two textboxes has some text inside on submit button click?

Answer 1

Along with two text boxes add a CustomValidator and call server side validation.

<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
<br />
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
<br />
<asp:CustomValidator ID="CustomValidator1" runat="server" ErrorMessage="CustomValidator" OnServerValidate="CustomValidator_ServerValidate"></asp:CustomValidator>
<br />
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Button" />

Server side function

public void CustomValidator_ServerValidate(object source, System.Web.UI.WebControls.ServerValidateEventArgs args)
    {
        args.IsValid = true;

        if (TextBox1.Text == "" && TextBox2.Text == "")
        {
            CustomValidator1.ErrorMessage = "Enter value in at least one text Box";
            args.IsValid = false;

        }
    }

Hope this helps you.

Answer 2

You can also use ClientValidationFunction attribute with CustomValidator and client side function

<asp:TextBox ID="txtBoxId1" runat="server"></asp:TextBox>
<asp:TextBox ID="txtBoxId2" runat="server"></asp:TextBox>
<asp:CustomValidator ID="cvId" runat="server" ClientValidationFunction="Validators.DoWork">
error</asp:CustomValidator>

<script language="javascript">
var Validators = {
DoWork: function (source, clientside_arguments) {

    var valid_val = true;

    //get the controls values using jQuery
    var txtBoxId1= $('input:text[id*=txtBoxId1]').val();
    var txtBoxId2= $('input:text[id*=txtBoxId2]').val();

    if (your condition) {
        valid_val = false;
    }

    clientside_arguments.IsValid = valid_val;
}
}
</script>