Validation And More: Getting ValidationSummary To Show On Events

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In creating various web apps, I use Peter Blum’s Professional Validation and More controls for page validation and error display. If you don’t, you really should. They’re much more flexible and robust than the Microsoft validation controls are.

One problem I ran into was in using the ValidationSummary control. I’m generating a huge form using all sorts of validation, and I want the ValidationSummary to display the list of errors on the form as they happen. The issue is, the ValidationSummary only displays when the user tries to submit the form - even if it’s a client-side validation, you only see it when the user clicks the submit button.

I wanted my ValidationSummary to display real-time, rather than waiting for the user to click the submit button. Here’s a little method you can use on your controls to make the page execute validation on a control event. Just pass in your control and the name of the event (“onclick,” “onchange,” etc.) and this will handle the rest.

/// <summary>
/// Adds a call to the VAM page validation to a specified control's event.
/// </summary>
/// <param name="control">The control that should call validation.</param>
/// <param name="eventName">The event that should fire validation (onClick, onChange, etc.)</param>
protected void AddPageValidationEvent(WebControl control, string eventName)
    var scriptKey = (string)control.ClientID + "_" + eventName + "_VAMValidate";
    if (!Page.IsStartupScriptRegistered(scriptKey))
        var scriptBase = "<script type=\"text/javascript\" language=\"javascript\">\n" +
            "<!-- \n" +
            "VAM_AttachEvent(VAM_GetById(\"{0}\"), \"{1}\", \"{2}\");\n" +
            "-->\n" +
        var eventAction = "VAM_ValidateGroup('', true);";
        var completeScript = string.Format(scriptBase, control.ClientID, eventName, eventAction);
        Page.RegisterStartupScript(scriptKey, completeScript);