I need to validate various ASP.NET controls, but instead of displaying the standard text/asterisk/image next to each when validation fails, I need to display custom content (change the outline color of the input textbox, display a tooltip, etc.). I could use a standard validation control in most cases (e.g., RequiredFieldValidator for a TextBox), except for the display when validation fails.
I've started out creating CustomValidators, but I need to do this many times for various validations (required field, regular expressions, ranges). It seems a waste to recreate the logic of these validators only so that it can change the response output. The MS documentation at http://msdn.microsoft.com/en-us/library/3w0bs977.aspx says a custom response can be done on both client and server in this case: "On both the client and server side you can create a custom response, such as a color change in a control or a font change for text on a label." It gives an example for the server side, but does not give a method for the client side. What is the best way to handle the custom response on the client?