Is it possible to use ASP.NET validation controls when I need to modify HTML when validation fails?

Question

Let's say that I have the following HTML for a text box on an ASP.NET page:

<div class="myClass">
    <asp:TextBox ID="txtMyTextBox" runat="server"></asp:TextBox>
</div>

It is easy enough to add a required field validator to this page like this.

<asp:RequiredFieldValidator ID="valMyTextBox" runat="server" ControlToValidate="txtMyTextBox" ErrorMessage="My Text Box is required."></asp:RequiredFieldValidator>

But I need to modify the HTML slightly if this text box fails validation. I need to add a CSS class to the DIV. So if the user leaves this field blank I need the HTML to look like this:

<div class="myClass error">
    <asp:TextBox ID="txtMyTextBox" runat="server"></asp:TextBox>
</div>

Is this possible? I can't figure out if there is a way to write code behind that only fires if this particular validator control fails validation or something. I know I can write code that runs when the entire page is not valid. But I just want this code to run when this validator returns invalid. Hope this makes sense.

Corey

this could be solved by javascript or any other scripting languages are you familiar with them? — Laurence Burke, Mar 16 '11 at 19:41
Yes, of course there are lots of different ways to solve this. Specifically I am trying to figure out if there is a way to solve this using ASP.NET validation controls. — Corey Burnett, Mar 16 '11 at 19:44
checkout this answer it might help http://stackoverflow.com/a/12806045/696978 — gsimoes, Aug 16 '13 at 22:46

score 0 · Answer 1 · answered Mar 16 '11 at 19:51

OK I think this might help even though I am not to sure on the exact ways to do this

<div class=<%Response.Write(validateTextBox())%>>

that function which would be on the server that you would call to change the name of the class depending on the text box

score 0 · Accepted Answer · edited May 23 '17 at 12:19

0

Actually I found the answer in a different StackOverflow question. You can see it here: How do I add an additional CSS class on a surrounding DIV for failed form validation?.

edited May 23 '17 at 12:19

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answered Mar 16 '11 at 19:53

Corey Burnett

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This requires a postback. An alternative is to create a custom validator, to which you can specify both a client-side javascript function which can do the client validation, and you can provide a backend function that will run when post-back occurs – Prescott Mar 16 '11 at 22:01

score 0 · Answer 3 · edited May 23 '17 at 11:56

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Another way to do it without Postback is to override the default asp.net validation scripts. I posted an example here: https://stackoverflow.com/a/9857696/618044

edited May 23 '17 at 11:56

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answered Mar 25 '12 at 03:48

Jeremy A. West

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Is it possible to use ASP.NET validation controls when I need to modify HTML when validation fails?

3 Answers3