CODEWITHSUNDEEP
c#asp.net
moe
moe

Reputation: 5249

How do i validate a field based on the input of another field

I have 2 fields and I need to make one of the fields a required fields only if the other field has content of "NO" value in it. So I have researched online and this is what I ended up having. The only question I have and need help with this is the first part of the code where it calls this: .getElementByID. How can I construct that? Or if you could shed some lights on will be great.

<script>
        function Validate(source, args) {
                if (document.getElementById('<%= TextBox1.ClientID %>').value.toUpperCase() == "NO" &&
                document.getElementById('<%= TextBox2.ClientID %>').value.length == 0)
                        args.IsValid = false;
                else
                        args.IsValid = true;
        }
</script>
</head>
<body>
        <form id="form1" runat="server">
        <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
        <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
        <asp:CustomValidator ID="CustomValidator1" runat="server" ErrorMessage="TextBox2 Should Be Filled"
                Display="Dynamic" ClientValidationFunction="Validate" OnServerValidate="CustomValidator1_ServerValidate"></asp:CustomValidator>
        <asp:Button ID="Button1" runat="server" Text="Button" />
        </form>
</body>
</html>

protected void Page_Load(object sender, EventArgs e)
        {
                if (!Page.IsPostBack)
                {
                        Page.Validate();
                        if (!Page.IsValid)
                                Response.Write("TextBox2 should be filled");

                }
        }

        protected void CustomValidator1_ServerValidate(object source, ServerValidateEventArgs args)
        {
                args.IsValid = !(this.TextBox1.Text.Equals("NO", StringComparison.CurrentCultureIgnoreCase) && this.TextBox2.Text.Length == 0);

Upvotes: 0

Views: 326

Answers (1)

Tim Schmelter
Tim Schmelter

Reputation: 460208

The first error within sight is:

if (!Page.IsPostBack)  // <--- here
{
        Page.Validate();
        if (!Page.IsValid)
                Response.Write("TextBox2 should be filled");

}

Change !Page.IsPostBack to Page.IsPostBack since it makes no sense to validate user input if the page was not posted back yet.

According to your question about your clientside validation code: what is the problem actually? Does your code work, do you get an exception, does it postback even if it's invalid? What's going wrong?

Upvotes: 4

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